ORCID Profile
0000-0002-5509-8071
Current Organisation
RMIT University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Materials Engineering | Metals and Alloy Materials | Materials Engineering not elsewhere classified | Biological Physics | Biophysics | Manufacturing Processes and Technologies (excl. Textiles) | Pyrometallurgy | Biomedical Engineering | Other Physical Sciences | Nanotechnology | Structural biology (incl. macromolecular modelling) | Colloid And Surface Chemistry | Biochemistry and cell biology not elsewhere classified | Powder and Particle Technology | Analytical Spectrometry | Synchrotrons; Accelerators; Instruments and Techniques | Nanofabrication growth and self assembly | Innovation and Technology Management | Functional Materials | Manufacturing Engineering | Nanotechnology | Cellular Interactions (Incl. Adhesion, Matrix, Cell Wall) | Biochemistry and cell biology | Colloid and Surface Chemistry | Interdisciplinary Engineering not elsewhere classified | Biomechanical Engineering | Biomaterials | Physical Chemistry (Incl. Structural) | Nanometrology | Nanoscale Characterisation | Nanomanufacturing | Nanomaterials | Condensed Matter Imaging | Nanobiotechnology
ANZSRC Socio-Economic Objective (SEO)
Coated Metal and Metal-Coated Products | Expanding Knowledge in Engineering | Expanding Knowledge in Technology | Basic Iron and Steel Products | Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in the Physical Sciences | Expanding Knowledge in the Biological Sciences | Education and Training Systems not elsewhere classified | Materials performance and processes | Emerging Defence Technologies | Fabricated Metal Products not elsewhere classified | Nautical equipment | Concentrating processes of other base metal ores | Structural Metal Products | Management of Solid Waste from Manufacturing Activities | Integrated Circuits and Devices | Diagnostics | Treatments (e.g. chemicals, antibiotics) | Soaps and cosmetics | Medical instrumentation | Manufacturing not elsewhere classified | Processed food products and beverages not elsewhere classified | Polymeric materials (e.g. paints) | Expanding Knowledge in the Earth Sciences | Medical Instruments |
Related Links
Publications
Impact of confining 3-D polymer networks on dynamics of bacterial ingress and self-organisation
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TB01880C
Abstract: Alignment of microbial colonies along with polymeric cell wall.
Structure and Chemical Organization in Damselfly Calopteryx haemorrhoidalis Wings: A Spatially Resolved FTIR and XRF Analysis with Synchrotron Radiation
Publisher: Springer Science and Business Media LLC
Date: 30-05-2018
DOI: 10.1038/S41598-018-26563-6
Abstract: Insects represent the majority of known animal species and exploit a variety of fascinating nanotechnological concepts. We investigated the wings of the damselfly Calopteryx haemorrhoidalis , whose males have dark pigmented wings and females have slightly pigmented wings. We used scanning electron microscopy (SEM) and nanoscale synchrotron X-ray fluorescence (XRF) microscopy analysis for characterizing the nanostructure and the elemental distribution of the wings, respectively. The spatially resolved distribution of the organic constituents was examined by synchrotron Fourier transform infrared (s-FTIR) microspectroscopy and subsequently analyzed using hierarchical cluster analysis. The chemical distribution across the wing was rather uniform with no evidence of melanin in female wings, but with a high content of melanin in male wings. Our data revealed a fiber-like structure of the hairs and confirmed the presence of voids close to its base connecting the hairs to the damselfly wings. Within these voids, all detected elements were found to be locally depleted. Structure and elemental contents varied between wing membranes, hairs and veins. The elemental distribution across the membrane was rather uniform, with higher Ca, Cu and Zn levels in the male damselfly wing membranes.
X-ray laser on transitions of Pd-like ions from ErXXIII to ReXXX
Publisher: IOP Publishing
Date: 31-10-2008
Wettability of natural superhydrophobic surfaces
Publisher: Elsevier BV
Date: 08-2014
DOI: 10.1016/J.CIS.2014.01.020
Abstract: Since the description of the 'Lotus Effect' by Barthlott and Neinhuis in 1997, the existence of superhydrophobic surfaces in the natural world has become common knowledge. Superhydrophobicity is associated with a number of possible evolutionary benefits that may be bestowed upon an organism, ranging from the ease of dewetting of their surfaces and therefore prevention of encumbrance by water droplets, self-cleaning and removal of particulates and potential pathogens, and even to antimicrobial activity. The superhydrophobic properties of natural surfaces have been attributed to the presence of hierarchical microscale (>1 μm) and nanoscale (typically below 200 nm) structures on the surface, and as a result, the generation of topographical hierarchy is usually considered of high importance in the fabrication of synthetic superhydrophobic surfaces. When one surveys the breadth of data available on naturally existing superhydrophobic surfaces, however, it can be observed that topographical hierarchy is not present on all naturally superhydrophobic surfaces in fact, the only universal feature of these surfaces is the presence of a sophisticated nanoscale structure. Additionally, several natural surfaces, e.g. those present on rose petals and gecko feet, display high water contact angles and high adhesion of droplets, due to the pinning effect. These surfaces are not truly superhydrophobic, and lack significant degrees of nanoscale roughness. Here, we discuss the phenomena of superhydrophobicity and pseudo-superhydrophobicity in nature, and present an argument that while hierarchical surface roughness may aid in the stability of the superhydrophobic effect, it is nanoscale surface architecture alone that is the true determinant of superhydrophobicity.
Fluorescence Colour Control in Perylene-Labeled Polymer Chains Trapped by Nanotextured Silicon.
Publisher: Wiley
Date: 27-01-2022
Abstract: The ability to modulate, tune, and control fluorescence colour has attracted much attention in photonics-related research fields. Thus far, it has been impossible to achieve fluorescence colour control (FCC) for material with a fixed structure, size, surrounding medium, and concentration. Here, we propose a novel approach to FCC using optical tweezers. We demonstrate an optical trapping technique using nanotextured Si (black-Si) that can efficiently trap polymer chains. By increasing the laser intensity, the local concentration of perylene-labelled water-soluble polymer chains increased inside the trapping potential. Accordingly, the excimer fluorescence of perylene increased while the monomer fluorescence decreased, evidenced by a fluorescence colour change from blue to orange. Using nanostructure-assisted optical tweezing, we demonstrate control of the relative intensity ratio of fluorescence of the two fluorophores, thus showing remote and reversible FCC of the polymer assembly.
Structure of an acidic polysaccharide from the agar-decomposing marine bacterium Pseudoalteromonas atlantica strain IAM 14165 containing 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulos
Publisher: Elsevier BV
Date: 2005
DOI: 10.1016/J.CARRES.2004.11.007
Abstract: The structure of an acidic polysaccharide from Pseudoalteromonas atlantica strain 14165 containing 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-manno-non-2-ulosonic acid (di-N-acetylpseudaminic acid, Pse5Ac7Ac) has been elucidated. The polysaccharide was studied by 1H and 13C NMR spectroscopy, including 2D experiments, along with sugar and methylation analyses. After a selective hydrolysis a modified polysaccharide devoid of its side chain could be isolated. It was found that the polysaccharide has pentasaccharide repeating units with following structure: [structure: see text].
Hydrophobicity of Nonwetting Soils
Publisher: Elsevier
Date: 2015
“Pseudoalteromonas januaria” SUT 11 as the Source of Rare Lipodepsipeptides
Publisher: Springer Science and Business Media LLC
Date: 08-01-2008
DOI: 10.1007/S00284-007-9023-6
Abstract: The marine bacterium "Pseudoalteromonas januaria" SUT 11 isolated from a seawater s le produced the rare cell-bound cyclic lipodepsipeptides A/A', B/B', and C/C'. The matrix-assisted laser desorption/ionization mass spectra indicated that one bromine atom presented in the peptides B/B' and C/C', whereas the component A/A' contained no bromine atom. The acyldepsipeptides A/A'-C/C' have an identical amino acid sequence, Thr-Val-Asn-Asn-Leu/allo-Ile, but differed in C-terminal amino acid and acyl moieties. Peptides A-C have Leu as a C-terminal amino acid, whereas peptides A'-C' have allo-Ile. Acyl moieties in peptides A/A', B/B', and C/C' have been found to consist of 11-(4'-hydroxyphenyl)-undeca-2,4,6,8,10-pentaenic acid, 9-(3'-bromo-4'-hydroxyphenyl)-nona-2,4,6,8-tetraenic acid, and 11-(3'-bromo-4'-hydroxyphenyl)-undeca-2,4,6,8,10-pentaenic acid, respectively. The structure of a main pair of peptides B/B' with molecular masses 843/845 Da has been determined by means of ultraviolet, infrared, and two-dimensional nuclear magnetic resonance spectroscopy. We have demonstrated that tandem nano-electrospray ionization mass spectrometry is a very efficient way for the fast and sensitive investigation of lipopeptides A/A' and C/C' with molecular masses 791 and 869/871 Da, respectively, which have been isolated in small amounts.
Plastic degradation and its environmental implications with special reference to poly(ethylene terephthalate)
Publisher: MDPI AG
Date: 28-12-2013
DOI: 10.3390/POLYM5010001
Nanotopography as a trigger for the microscale, autogenous and passive lysis of erythrocytes
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4TB00239C
Abstract: A mechano-responsive topology provides a highly active yet autogenous surface for erythrocyte lysis towards microfluidic haematology platforms.
Alteromonas australica sp. nov., isolated from the Tasman Sea
Publisher: Springer Science and Business Media LLC
Date: 06-01-2013
DOI: 10.1007/S10482-012-9869-X
Abstract: A non-pigmented, motile, Gram-negative bacterium designated H 17(T) was isolated from a seawater s le collected in Port Phillip Bay (the Tasman Sea, Pacific Ocean). The new organism displayed optimal growth between 4 and 37 °C, was found to be neutrophilic and slightly halophilic, tolerating salt water environments up to 10 % NaCl. Strain H 17(T) was found to be able to degrade starch and Tween 80 but unable to degrade gelatin or agar. Phosphatidylglycerol (27.7 %) and phosphatidylethanolamine (72.3 %) were found to be the only associated phospholipids. The major fatty acids identified are typical for the genus Alteromonas and include C16:0, C16:1ω7, C17:1ω8 and C18:1ω7. The G+C content of the DNA was found to be 43.4 mol%. A phylogenetic study, based on the 16S rRNA gene sequence analysis and Multilocus Phylogenetic Analysis, clearly indicated that strain H 17(T) belongs to the genus Alteromonas. The DNA-DNA relatedness between strain H 17(T) and the validly named Alteromonas species was between 30.7 and 46.4 mol%. Based on these results, a new species, Alteromonas australica, is proposed. The type strain is H 17(T) (= KMM 6016(T) = CIP 109921(T)).
Mechano-bactericidal mechanism of graphene nanomaterials
Publisher: The Royal Society
Date: 20-04-2018
Abstract: Growing interest in the bactericidal effect of graphene and graphene-derived nanomaterials has led to the investigation and effective publication of the bactericidal effects of the substratum, many of which present highly conflicting material. The nature of bacterial cell death on graphene bio-interfaces, therefore, remains poorly understood. Here, we review recent findings on the bactericidal effect of graphene and graphene-derived nanomaterials, and proposed mechanisms of cell inactivation, due to mechanical contact with graphene materials, including lipid extraction, physical damage to membranes and pore formation.
The Family Granulosicoccaceae
Publisher: Springer Berlin Heidelberg
Date: 2014
Spinodal decomposition and the emergence of dissipative transient periodic spatio-temporal patterns in acentrosomal microtubule multitudes of different morphology
Publisher: AIP Publishing
Date: 06-2013
DOI: 10.1063/1.4807909
Abstract: We have studied a spontaneous self-organization dynamics in a closed, dissipative (in terms of guansine 5′-triphosphate energy dissipation), reaction-diffusion system of acentrosomal microtubules (those nucleated and organized in the absence of a microtubule-organizing centre) multitude constituted of straight and curved acentrosomal microtubules, in highly crowded conditions, in vitro. Our data give experimental evidence that cross-diffusion in conjunction with excluded volume is the underlying mechanism on basis of which acentrosomal microtubule multitudes of different morphologies (straight and curved) undergo a spatial-temporal demix. Demix is constituted of a bifurcation process, manifested as a slow isothermal spinodal decomposition, and a dissipative process of transient periodic spatio-temporal pattern formation. While spinodal decomposition is an energy independent process, transient periodic spatio-temporal pattern formation is accompanied by energy dissipative process. Accordingly, we have determined that the critical threshold for slow, isothermal spinodal decomposition is 1.0 ± 0.05 mg/ml of microtubule protein concentration. We also found that periodic spacing of transient periodic spatio-temporal patterns was, in the overall, increasing versus time. For illustration, we found that a periodic spacing of the same pattern was 0.375 ± 0.036 mm, at 36 °C, at 155th min, while it was 0.540 ± 0.041 mm at 31 °C, and at 275th min after microtubule assembly started. The lifetime of transient periodic spatio-temporal patterns spans from half an hour to two hours approximately. The emergence of conditions of macroscopic symmetry breaking (that occur due to cross-diffusion in conjunction with excluded volume) may have more general but critical importance in morphological pattern development in complex, dissipative, but open cellular systems.
Decontamination-Induced Modification of Bioactivity in Essential Oil-Based Plasma Polymer Coatings
Publisher: MDPI AG
Date: 25-11-2021
DOI: 10.3390/MOLECULES26237133
Abstract: Plasma polymer coatings fabricated from Melaleuca alternifolia essential oil and its derivatives have been previously shown to reduce the extent of microbial adhesion on titanium, polymers, and other implantable materials used in dentistry. Previous studies have shown these coatings to maintain their performance under standard operating conditions however, when used in e.g., a dental implant, these coatings may inadvertently become subject to in situ cleaning treatments, such as those using an atmospheric pressure plasma jet, a promising tool for the effective in situ removal of biofilms from tissues and implant surfaces. Here, we investigated the effect of such an exposure on the antimicrobial performance of the Melaleuca alternifolia polymer coating. It was found that direct exposure of the polymer coating surface to the jet for periods less than 60 s was sufficient to induce changes in its surface chemistry and topography, affecting its ability to retard subsequent microbial attachment. The exact effect of the jet exposure depended on the chemistry of the polymer coating, the length of plasma treatment, cell type, and incubation conditions. The change in the antimicrobial activity for polymer coatings fabricated at powers of 20–30 W was not statistically significant due to their limited baseline bioactivity. Interestingly, the bioactivity of polymer coatings fabricated at 10 and 15 W against Staphylococcus aureus cells was temporarily improved after the treatment, which could be attributed to the generation of loosely attached bioactive fragments on the treated surface, resulting in an increase in the dose of the bioactive agents being eluted by the surface. Attachment and proliferation of Pseudomonas aeruginosa cells and mixed cultures were less affected by changes in the bioactivity profile of the surface. The sensitivity of the cells to the change imparted by the jet treatment was also found to be dependent on their origin culture, with mature biofilm-derived P. aeruginosa bacterial cells showing a greater ability to colonize the surface when compared to its planktonic broth-grown counterpart. The presence of plasma-generated reactive oxygen and nitrogen species in the culture media was also found to enhance the bioactivity of polymer coatings fabricated at power levels of 10 and 15 W, due to a synergistic effect arising from simultaneous exposure of cells to reactive oxygen and nitrogen species (RONS) and eluted bioactive fragments. These results suggest that it is important to consider the possible implications of inadvertent changes in the properties and performance of plasma polymer coatings as a result of exposure to in situ decontamination, to both prevent suboptimal performance and to exploit possible synergies that may arise for some polymer coating-surface treatment combinations.
Cytotoxicity and biocompatibility of metallic biomaterials
Publisher: Elsevier
Date: 2014
Laser-Induced µ-Rooms for Osteocytes on Implant Surface: An In Vivo Study
Publisher: MDPI AG
Date: 28-11-2022
DOI: 10.3390/NANO12234229
Abstract: Laser processing of dental implant surfaces is becoming a more widespread replacement for classical techniques due to its undeniable advantages, including control of oxide formation and structure and surface relief at the microscale. Thus, using a laser, we created several biomimetic topographies of various shapes on the surface of titanium screw-shaped implants to research their success and survival rates. A distinctive feature of the topographies is the presence of “µ-rooms”, which are special spaces created by the depressions and elevations and are analogous to the µ-sized room in which the osteocyte will potentially live. We conducted the comparable in vivo study using dental implants with continuous (G-topography with µ-canals), discrete (S-topography with μ-cavities), and irregular (I-topography) laser-induced topographies. A histological analysis performed with the statistical method (with p-value less than 0.05) was conducted, which showed that G-topography had the highest BIC parameter and contained the highest number of mature osteocytes, indicating the best secondary stability and osseointegration.
Antibacterial Action of Nanoparticles by Lethal Stretching of Bacterial Cell Membranes
Publisher: Wiley
Date: 12-11-2020
Lipid Composition of Novel Shewanella Species Isolated from Far Eastern Seas
Publisher: Springer Science and Business Media LLC
Date: 11-2005
Nanostructured Antireflective and Thermoisolative Cicada Wings
Publisher: American Chemical Society (ACS)
Date: 29-04-2016
DOI: 10.1021/ACS.LANGMUIR.6B00621
Abstract: Inter-related mechanical, thermal, and optical macroscopic properties of biomaterials are defined at the nanoscale by their constituent structures and patterns, which underpin complex functions of an entire bio-object. Here, the temperature diffusivity of a cicada (Cyclochila australasiae) wing with nanotextured surfaces was measured using two complementary techniques: a direct contact method and IR imaging. The 4-6-μm-thick wing section was shown to have a thermal diffusivity of α⊥ = (0.71 ± 0.15) × 10(-7) m(2)/s, as measured by the contact temperature wave method along the thickness of the wing it corresponds to the inherent thermal property of the cuticle. The in-plane thermal diffusivity value of the wing was determined by IR imaging and was considerably larger at α∥ = (3.6 ± 0.2) × 10(-7) m(2)/s as a result of heat transport via air. Optical properties of wings covered with nanospikes were numerically simulated using an accurate 3D model of the wing pattern and showed that light is concentrated between spikes where intensity is enhanced by up to 3- to 4-fold. The closely packed pattern of nanospikes reduces the reflectivity of the wing throughout the visible light spectrum and over a wide range of incident angles, hence acting as an antireflection coating.
Silicon-Doped Graphene Oxide Quantum Dots as Efficient Nanoconjugates for Multifunctional Nanocomposites
Publisher: American Chemical Society (ACS)
Date: 25-01-2022
Abstract: Graphene oxide quantum dots (GOQDs) hold great promise as a new class of high-performance carbonaceous nanomaterials due to their numerous functional properties, such as tunable photoluminescence (PL), excellent thermal and chemical stability, and superior biocompatibility. In this study, we developed a facile, one-pot, and effective strategy to engineer the interface of GOQDs through covalent doping with silicon. The successful covalent attachment of the silane dopant with pendant vinyl groups to the edges of the GOQDs was confirmed by an in-depth investigation of the structural and morphological characteristics. The Si-GOQD nanoconjugates had an average dimension of ∼8 nm, with a graphite-structured core and amorphous carbon on their shell. We further used the infrared nanoimaging based on scattering-type scanning near-field optical microscopy to unveil the spectral near-field response of GOQD s les and to measure the nanoscale IR response of its network we then demonstrated their distinct domains with strongly enhanced near fields. The doping of Si atoms into the sp
Proposal for precision wavelength measurement of the Ni-like gadolinium x-ray laser formed during the interaction of a nanostructured target with an ultrashort laser beam
Publisher: IOP Publishing
Date: 09-09-2015
Peculiarities of adhesion of epiphytic bacteria on leaves of the seagrass Zostera marina and on abiotic surfaces
Publisher: Pleiades Publishing Ltd
Date: 08-2007
Advancing of 3D-Printed Titanium Implants with Combined Antibacterial Protection Using Ultrasharp Nanostructured Surface and Gallium-Releasing Agents
Publisher: American Chemical Society (ACS)
Date: 29-12-2021
DOI: 10.1021/ACSBIOMATERIALS.1C01030
Abstract: This paper presents the development of advanced Ti implants with enhanced antibacterial activity. The implants were engineered using additive manufacturing three-dimensional (3D) printing technology followed by surface modification with electrochemical anodization and hydrothermal etching, to create unique hierarchical micro/nanosurface topographies of microspheres covered with sharp nanopillars that can mechanically kill bacteria in contact with the surface. To achieve enhanced antibacterial performance, fabricated Ti implant models were loaded with gallium nitrate as an antibacterial agent. The antibacterial efficacy of the fabricated substrates with the combined action of sharp nanopillars and locally releasing gallium ions (Ga
Plasma for aquaponics
Publisher: Elsevier BV
Date: 2023
DOI: 10.1016/J.TIBTECH.2022.08.001
Abstract: Global environmental, social, and economic challenges call for innovative solutions to food production. Current food production systems require advances beyond traditional paradigms, acknowledging the complexity arising from sustainability and a present lack of awareness about technologies that may help limit, for ex le, loss of nutrients from soil. Aquaponics, a closed-loop system that combines aquaculture with hydroponics, is a step towards the more efficient management of scarce water, land, and nutrient resources. However, its large-scale use is currently limited by several significant challenges of maintaining desirable water chemistry and pH, managing infections in fish and plants, and increasing productivity efficiently, economically, and sustainably. This paper investigates the opportunities presented by plasma technologies in meeting these challenges, potentially opening new pathways for sustainability in food production.
Computational prediction of microRNAs in marine bacteria of the genus Thalassospira
Publisher: Public Library of Science (PLoS)
Date: 12-03-2019
An improved assembly and annotation of the allohexaploid wheat genome identifies complete families of agronomic genes and provides genomic evidence for chromosomal translocations
Publisher: Cold Spring Harbor Laboratory
Date: 18-04-2017
Abstract: Advances in genome sequencing and assembly technologies are generating many high-quality genome sequences, but assemblies of large, repeat-rich polyploid genomes, such as that of bread wheat, remain fragmented and incomplete. We have generated a new wheat whole-genome shotgun sequence assembly using a combination of optimized data types and an assembly algorithm designed to deal with large and complex genomes. The new assembly represents % of the genome with a scaffold N50 of 88.8 kb that has a high fidelity to the input data. Our new annotation combines strand-specific Illumina RNA-seq and Pacific Biosciences (PacBio) full-length cDNAs to identify 104,091 high-confidence protein-coding genes and 10,156 noncoding RNA genes. We confirmed three known and identified one novel genome rearrangements. Our approach enables the rapid and scalable assembly of wheat genomes, the identification of structural variants, and the definition of complete gene models, all powerful resources for trait analysis and breeding of this key global crop.
Poly(ethylene terephthalate) polymer surfaces as a substrate for bacterial attachment and biofilm formation
Publisher: Japanese Society of Microbial Ecology
Date: 2009
Abstract: Plastic debris causes extensive damage to the marine environment, largely due to its ability to resist degradation. Attachment on plastic surfaces is a key initiation process for their degradation. The tendency of environmental marine bacteria to adhere to poly(ethylene terephthalate) (PET) plastic surfaces as a model material was investigated. It was found that the overall number of heterotrophic bacteria in a s le of sea water taken from St. Kilda Beach, Melbourne, Australia, was significantly reduced after six months from 4.2-4.7×10(3) cfu mL(-1) to below detectable levels on both full-strength and oligotrophic marine agar plates. The extinction of oligotrophs after six months was detected in all s les. In contrast, the overall bacterial number recovered on full strength marine agar from the s le flasks with PET did not dramatically reduce. Heterotrophic bacteria recovered on full-strength marine agar plates six months after the commencement of the experiment were found to have suitable metabolic activity to survive in sea water while attaching to the PET plastic surface followed by the commencement of biofilm formation.
X-ray laser near 13.5 and 11.3 nm in Xe26+ driven by an intense pump laser interacting with xenon cluster jet as a promising radiation source for nanolithography
Publisher: IOP Publishing
Date: 07-04-2017
Superhydrophobic Polymers
Publisher: Elsevier
Date: 2015
Erratum: 18 GHz electromagnetic field induces permeability of Gram-positive cocci (Scientific Reports (2015) 5 (10980) doi: 10.1038/srep10980))
Publisher: Springer Science and Business Media LLC
Date: 02-09-2015
DOI: 10.1038/SREP13507
Abstract: The effect of electromagnetic field (EMF) exposures at the microwave (MW) frequency of 18 GHz, on four cocci, Planococcus maritimus KMM 3738, Staphylococcus aureus CIP 65.8 T , S. aureus ATCC 25923 and S. epidermidis ATCC 14990 T , was investigated. We demonstrate that exposing the bacteria to an EMF induced permeability in the bacterial membranes of all strains studied, as confirmed directly by transmission electron microscopy (TEM), and indirectly via the propidium iodide assay and the uptake of silica nanospheres. The cells remained permeable for at least nine minutes after EMF exposure. It was shown that all strains internalized 23.5 nm nanospheres, whereas the internalization of the 46.3 nm nanospheres differed amongst the bacterial strains ( S. epidermidis ATCC 14990 T ~ 0% Staphylococcus aureus CIP 65.8 T S. aureus ATCC 25923, ~40% Planococcus maritimus KMM 3738, ~80%). Cell viability experiments indicated that up to 84% of the cells exposed to the EMF remained viable. The morphology of the bacterial cells was not altered, as inferred from the scanning electron micrographs, however traces of leaked cytosolic fluids from the EMF exposed cells could be detected. EMF-induced permeabilization may represent an innovative, alternative cell permeability technique for applications in biomedical engineering, cell drug delivery and gene therapy.
Natural polymer biomaterials: advanced applications
Publisher: Elsevier
Date: 2014
Translocation of silica nanospheres through giant unilamellar vesicles (GUVs) induced by a high frequency electromagnetic field
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1RA05459G
Abstract: Membrane model systems capable of mimicking live cell membranes were used for the first time in studying the effects arising from electromagnetic fields (EMFs) of 18 GHz where membrane permeability was observed following exposure.
Critical Review of Nanopillar-Based Mechanobactericidal Systems
Publisher: American Chemical Society (ACS)
Date: 05-01-2022
Metallic biomaterials: types and advanced applications
Publisher: Elsevier
Date: 2014
A study of a retention of antimicrobial activity by plasma polymerized terpinen-4-ol thin films
Publisher: Trans Tech Publications, Ltd.
Date: 06-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.654-656.2261
Abstract: Terpinen-4-ol is the main constituent of Melaleuca alternifolia essential oil known for its biocidal and anti-inflammatory properties. The possibility of fabricating polymer thin films from terpinen-4-ol using radio frequency (RF) plasma polymerisation for the prevention of the growth of Pseudomonas aeruginosa was investigated, and the properties of the resultant films compared against their biologically active precursor. Films fabricated at 10 W prevented bacterial attachment and EPS secretion, whilst polyterpenol films deposited at 25 W demonstrated no biocidal activity against the pathogen.
Three-dimensional visualization of nanostructured surfaces and bacterial attachment using Autodesk (R) Maya (R)
Publisher: Springer Science and Business Media LLC
Date: 28-02-2014
DOI: 10.1038/SREP04228
Nanopillar Polymer Films as Antibacterial Packaging Materials
Publisher: American Chemical Society (ACS)
Date: 04-02-2022
Ecophysiological diversity of a novel member of the genus Alteromonas, and description of Alteromonas mediterranea sp. nov.
Publisher: Springer Science and Business Media LLC
Date: 19-10-2014
DOI: 10.1007/S10482-014-0309-Y
Abstract: Nine non-pigmented, motile, Gram-negative bacteria originally designated as Alteromonas macleodii deep-sea ecotypes, were isolated from seawater s les collected from four separate locations two deep-sea sites in the Mediterranean Sea and surface water of the Aegean Sea and English Channel. The six strains studied in vitro were found to tolerate up to 20 % NaCl. The DNA-DNA relatedness between the deep-sea ecotype strains was found to be between 75 and 89 %, whilst relatedness with the validly named Alteromonas species was found to be between 31 and 69 %. The average nucleotide identity (ANI) amongst the deep-sea ecotype strains was found to be 98-100 % the in silico genome-to-genome distance (GGD), 85-100 % the average amino acid identity (AAI) of all conserved protein-coding genes, 95-100 % and the strains possessed 30-32 of the Karlin's genomic signature dissimilarity. The ANI between the deep-sea ecotype strains and A. macleodii ATCC 27126(T) and Alteromonas australica H 17(T) was found to be 80.6 and 74.6 %, respectively. A significant correlation was observed between the phenotypic data obtained in vitro and data retrieved in silico from whole genome sequences. The results of a phylogenetic study that incorporated a 16S rRNA gene sequence analysis, multilocus phylogenetic analysis (MLPA) and genomic analysis, together with the physiological, biochemical and chemotaxonomic data, clearly indicated that the group of deep-sea ecotype strains represents a distinct species within the genus Alteromonas. Based on these data, a new species, Alteromonas mediterranea, is proposed. The type strain is DE(T) ( = CIP 110805(T) = LMG 28347(T) = DSM 17117(T)).
The Fate of Osteoblast-Like MG-63 Cells on Pre-Infected Bactericidal Nanostructured Titanium Surfaces
Publisher: MDPI AG
Date: 14-05-2019
DOI: 10.3390/MA12101575
Abstract: Biomaterials that have been newly implanted inside the body are the substratum targets for a “race for the surface”, in which bacterial cells compete against eukaryotic cells for the opportunity to colonize the surface. A victory by the former often results in biomaterial-associated infections, which can be a serious threat to patient health and can undermine the function and performance of the implant. Moreover, bacteria can often have a ‘head start’ if implant contamination has taken place either prior to or during the surgery. Current prevention and treatment strategies often rely on systemic antibiotic therapies, which are becoming increasingly ineffective due to a growing prevalence of antibiotic-resistant bacteria. Nanostructured surfaces that kill bacteria by physically rupturing bacterial cells upon contact have recently emerged as a promising solution for the mitigation of bacterial colonization of implants. Furthermore, these nanoscale features have been shown to enhance the adhesion and proliferation of eukaryotic cells, which is a key to, for ex le, the successful osseointegration of load-bearing titanium implants. The bactericidal activity and biocompatibility of such nanostructured surfaces are often, however, examined separately, and it is not clear to what extent bacterial cell-surface interactions would affect the subsequent outcomes of host-cell attachment and osseointegration processes. In this study, we investigated the ability of bactericidal nanostructured titanium surfaces to support the attachment and growth of osteoblast-like MG-63 human osteosarcoma cells, despite them having been pre-infected with pathogenic bacteria. MG-63 is a commonly used osteoblastic model to study bone cell viability, adhesion, and proliferation on the surfaces of load-bearing biomaterials, such as titanium. The nanostructured titanium surfaces used here were observed to kill the pathogenic bacteria, whilst simultaneously enhancing the growth of MG-63 cells in vitro when compared to that occurring on sterile, flat titanium surfaces. These results provide further evidence in support of nanostructured bactericidal surfaces being used as a strategy to help eukaryotic cells win the “race for the surface” against bacterial cells on implant materials.
Bacterial patterning at the three-phase line of contact with microtextured alkanes
Publisher: Informa UK Limited
Date: 16-03-2015
DOI: 10.1080/08927014.2015.1038706
Abstract: Aliphatic crystallites, characteristic of the eicosane and docosane components of naturally occurring lipids, were found to form microtextures that were structured by specific interactions with ordered graphite (HOPG) used as the underlying substratum, as confirmed by scanning electron microscopy (SEM) and fast Fourier transform (FFT) analysis. Confocal scanning laser microscopy (CLSM) showed highly directed bacterial alignment for two bacterial species (spherical and rod-shaped), reflecting the preferential orientation of the crystallite-air-water interfaces to give linear and triangular bacterial patterning. The mechanisms of bacterial attachment are demonstrated in terms of the balance between effective radial adhesional forces and the capillary forces resulting from the water contact angle of the bacteria at the three-phase line (TPL) of the lipid surface. It is suggested that these microtextured surfaces, which exhibit the ability to limit bacterial adhesion to a precise patterning at the lipid TPL, could be used as a means of controlling bacterial colonization.
Renewable Bio-anodes for Microbial Fuel Cells
Publisher: Springer International Publishing
Date: 08-12-2017
A highly active alkaline phosphatase from the marine bacterium Cobetia
Publisher: Springer Science and Business Media LLC
Date: 26-05-2005
DOI: 10.1007/S10126-004-3022-4
Abstract: An alkaline phosphatase with unusually high specific activity has been found to be produced by the marine bacterium Cobetia marina (strain KMM MC-296) isolated from coelomic liquid of the mussel Crenomytilus grayanus. The properties of enzyme, such as a very high specific activity (15000 DE U/1 mg of protein), no activation with alent cations, resistance to high concentrations of inorganic phosphorus, as well as substrate specificity toward 5' nucleotides suggest that the enzyme falls in an intermediate position between unspecific alkaline phosphatases (EC 3.1.3.1) and 5' nucleotidases (EC 3.1.3.5).
Tone reversal of an AFM lateral force image due to hybridization of oligonucleotides immobilized on polymers
Publisher: Wiley
Date: 28-04-2005
Engineering the Interface: Nanodiamond Coating on 3D-Printed Titanium Promotes Mammalian Cell Growth and Inhibits Staphylococcus aureus Colonization
Publisher: American Chemical Society (ACS)
Date: 14-06-2019
Abstract: Additively manufactured selective laser melted titanium (SLM-Ti) opens the possibility of tailored medical implants for patients. Despite orthopedic implant advancements, significant problems remain with regard to suboptimal osseointegration at the interface between the implant and the surrounding tissue. Here, we show that applying a nanodiamond (ND) coating onto SLM-Ti scaffolds provides an improved surface for mammalian cell growth while inhibiting colonization of
Molecular Organization of the Nanoscale Surface Structures of the Dragonfly Hemianax papuensis Wing Epicuticle
Publisher: Public Library of Science (PLoS)
Date: 09-07-2013
Celeribacter neptunius gen. nov., sp. nov., a new member of the class Alphaproteobacteria
Publisher: Microbiology Society
Date: 07-2010
Abstract: A whitish Gram-negative, motile, aerobic bacterium, designated strain H 14 T , was isolated from seawater collected at St Kilda beach in Port Phillip Bay, Melbourne, Australia. Analysis of 16S rRNA gene sequences revealed that the organism belonged to the Roseobacter lineage of the class Alphaproteobacteria , forming a distinct evolutionary lineage at the genus level. Strain H 14 T was distantly related to the genera Nautella , Ruegeria and Pseudoruegeria (family Rhodobacteraceae ). Strain H 14 T was unable to degrade gelatin, casein, chitin, agar and starch, did not produce any carotenoids, did not possess bacteriochlorophyll a and had a limited ability to utilize carbon sources. Strain H 14 T grew with concentrations of 1–8 % (w/v) NaCl and over a temperature range of 5–35 °C. Phosphatidylglycerol was the major phospholipid (90 %) phosphatidylcholine (7.9 %) and phosphatidylethanolamine (2.0 %) were present in minor quantities. The predominant fatty acids were C 18 : 1 ω 7 c (82.4 %), C 18 : 1 ω 9 c (5.1 %) and C 18 : 0 (3.8 %). The DNA G+C composition for strain H 14 T was 59.1 mol%. Based on the results of physiological, biochemical, chemotaxonomic and phylogenetic investigations, a new genus, Celeribacter gen. nov., with the type species Celeribacter neptunius sp. nov. is proposed. The type strain of the type species is H 14 T (=KMM 6012 T =CIP 109922 T ).
Roughness parameters for standard description of surface nanoarchitecture
Publisher: Wiley
Date: 13-02-2012
DOI: 10.1002/SCA.21002
Abstract: The nanoarchitecture and surface roughness of metallic thin films prepared by magnetron sputtering were analyzed to determine the topographical statistics that give the optimum description of their nanoarchitechture. Nanoscale topographical profiles were generated by performing atomic force microscopy (AFM) scans of 1 μm × 1 μm areas of titanium and silver films of three different thicknesses (3 nm, 12 nm, and 150 nm). Of the titanium films, the 150-nm film had the highest average roughness (R(a) = 2.63 nm), more than four times that of the 3-nm and 12-nm titanium films. When silver films were coated on top of 150-nm titanium films, the average roughness increased further the 3-nm (R(a) = 4.96 nm) and 150-nm (R(a) = 4.65 nm) silver films average roughnesses were approximately twice that of the 150-nm titanium film. For topographical analysis, seven statistical parameters were calculated. These parameters included commonly used roughness measurements, as well as some less commonly used measurements, in order to determine which combination of parameters gave the best overall description of the nanoarchitecture of the films presented. Skewness (R(skw)), surface area increase (R(sa)), and peak counts (R(pc)) provided the best description of horizontal surface dimensions, and in conjunction with vertical descriptors R(a) and R(q) gave the best characterization of surface architecture. The five roughness parameters R(a), R(q), R(skw), R(sa), and R(pc) are proposed as a new standard for describing surface nanoarchitecture.
Alteromonas addita sp. nov.
Publisher: Microbiology Society
Date: 05-2005
Abstract: On the basis of phenotypic, genotypic characteristics and analysis of 16S rRNA gene sequences, a novel species belonging to the genus Alteromonas is described. A non-pigmented, motile, Gram-negative bacterium designated R10SW13 T was isolated from sea water s les collected in Chazhma Bay (Sea of Japan, Pacific Ocean). The novel organism mainly grew between 4 °C and 37 °C, was neutrophilic and slightly halophilic, tolerating up to 10 % NaCl. Strain R10SW13 T was haemolytic and was able to degrade starch and Tween 80 and to degrade gelatin and agar weakly, but did not degrade casein. Phosphatidylethanolamine (44·3±0·9 %) and phosphatidylglycerol (55·7±0·9 %) were the predominant phospholipids. The major fatty acids formed were typical for the genus Alteromonas , including 16 : 0, 16 : 1 ω -7 and 18 : 1 ω -7. The G+C content of the DNA was 43·4 mol%. DNA–DNA hybridization experiments showed 38–53 % binding with the DNAs of type strains of phylogenetically related species of the genus Alteromonas , namely: Alteromonas macleodii , Alteromonas marina , Alteromonas stellipolaris , Alteromonas litorea , ‘ Alteromonas macleodii subsp. fijiensis ’ and ‘ Alteromonas infernus ’. Based on these results, a novel species, Alteromonas addita sp. nov., is proposed, with strain R10SW13 T (=KMM 3600 T =KCTC 12195 T =LMG 22532 T ) as the type strain.
Assessment of interfacial interactions between starch and non-isocyanate polyurethanes in their hybrids
Publisher: Elsevier BV
Date: 10-2020
The Bioeffects Resulting from Prokaryotic Cells and Yeast Being Exposed to an 18 GHz Electromagnetic Field
Publisher: Public Library of Science (PLoS)
Date: 08-07-2016
Imaging the air-water interface: Characterising biomimetic and natural hydrophobic surfaces using in situ atomic force microscopy
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.JCIS.2018.10.059
Abstract: The interface between water and a textured hydrophobic surface can exist in two regimes either the Wenzel (surface-engulfed) or Cassie-Baxter (water-suspended) state. Better understanding of the influence of pattern geometry and spacing is crucial for the design of functional (super)hydrophobic surfaces, as inspired by numerous ex les in nature. In this work, we have employed litude modulated - atomic force microscopy to visualize the air-water interface with an unprecedented degree of clarity on a superhydrophobic and a highly hydrophobic nanostructured surface. The images obtained provide the first real-time experimental visualization of the Cassie-Baxter wetting on the surface of biomimetic silicon nanopillars and a naturally superhydrophobic cicada wing. For both surfaces, the air-water interface was found to be remarkably well-defined, revealing a distinctly nanostructured air-water interface in the interstitial spacing. The degree of interfacial texture differed as a function of surface geometry. These results reveal that the air-water interface is heterogeneous in its structure and confirmed the presence of short-range interfacial ordering. Additionally, the overpressure values for each point on the interface were calculated, quantifying the difference in wetting behavior for the biomimetic and natural surface. Results suggest that highly-ordered, closely spaced nanofeatures facilitate robust Cassie-Baxter wetting states and therefore, can enhance the stability of (super)hydrophobic surfaces.
Structure of the O-specific polysaccharide from Shewanella japonica type strain KMM 3299T containing the rare amino sugar Fuc4NAc
Publisher: Elsevier BV
Date: 06-2005
DOI: 10.1016/J.CARRES.2005.01.040
Abstract: An acidic O-specific polysaccharide (PS) of the agar-digesting bacterium Shewanella japonica with the type strain KMM 3299(T) was obtained by mild acid hydrolysis of the lipopolysaccharide. The polysaccharide was studied by component analysis, methylation analysis, (1)H and (13)C NMR spectroscopy, including 2D NMR experiments. The PS was determined to have the following structure involving three unusual amino sugars:
Incoherent Optical Tweezers on Black Titanium
Publisher: American Chemical Society (ACS)
Date: 04-06-2021
Optically self-photopumped x-ray laser at 13.4 nm in Ni-like tin (Sn22+)
Publisher: IOP Publishing
Date: 26-07-2018
A comparative study between the adsorption and covalent binding of human immunoglobulin and lysozyme on surface-modified poly(tert-butyl methacrylate)
Publisher: IOP Publishing
Date: 03-2006
DOI: 10.1088/1748-6041/1/1/004
Abstract: The adsorption and covalent immobilization of human immunoglobulin (HIgG) and lysozyme (LYZ) on surface-modified poly(tert-butyl methacrylate) PtBMA films have been evaluated using x-ray photoelectron spectroscopy (XPS), ellipsometry and atomic force microscopy (AFM). Surface modification of PtBMA (UV irradiation) afforded surfaces suitable for both the physical and covalent attachment of proteins. The XPS and ellipsometry results showed good correlation in terms of variable-dense/thickness protein layer formation between physisorbed and covalently bound proteins. The amount of physisorbed HIgG ranged from 23.0 +/- 1.6 ng mm(2) on PtBMA, with corresponding film thicknesses 17.0 +/- 1.2 nm. Covalent immobilization mediated through 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/N-hydroxysulfosuccinimide (sulfo-NHS) coupling chemistry, afforded 5.6-8 ng mm(2) of HIgG with a corresponding thickness of 5.9 +/- 0.6 nm on PtBMA. The attachment of LYZ to modified PtBMA surface was similarly translated, where adsorption yielded up to 15 ng mm(2), while covalent immobilization afforded typically 7-8 ng mm(2). The thickness of the adsorbed LYZ protein layer was 11.0 +/- 3.2 nm (PtBMA), suggesting the greater portion of protein adsorbs on surface-modified PtBMA.
Attenuated total reflection FTIR microspectroscopy at the Australian synchrotron
Publisher: OSA
Date: 2016
Natural Superhydrophobic Surfaces
Publisher: Elsevier
Date: 2015
Synchrotron macro ATR-FTIR microspectroscopic analysis of silica nanoparticle-embedded polyester coated steel surfaces subjected to prolonged UV and humidity exposure
Publisher: Public Library of Science (PLoS)
Date: 18-12-2017
Modulation of MG-63 Osteogenic Response on Mechano-Bactericidal Micronanostructured Titanium Surfaces
Publisher: American Chemical Society (ACS)
Date: 07-03-2023
The effect of a high frequency electromagnetic field in the microwave range on red blood cells
Publisher: Springer Science and Business Media LLC
Date: 07-09-2017
DOI: 10.1038/S41598-017-11288-9
Abstract: The effect of red blood cells (RBC) exposed to an 18 GHz electromagnetic field (EMF) was studied. The results of this study demonstrated for the first time that exposure of RBCs to 18 GHz EMF has the capacity to induce nanospheres uptake in RBCs. The uptake of nanospheres (loading efficiency 96% and 46% for 23.5 and 46.3 nm nanospheres respectively), their presence and locality were confirmed using three independent techniques, namely scanning electron microscopy, confocal laser scanning microscopy and transmission electron microscopy. It appeared that 23.5 nm nanospheres were translocated through the membrane into the cytosol, while the 46.3 nm-nanospheres were mostly translocated through the phospholipid-cholesterol bilayer, with only some of these nanospheres passing the 2D cytoskeleton network. The nanospheres uptake increased by up to 12% with increasing temperature from 33 to 37 °C. The TEM analysis revealed that the nanospheres were engulfed by the cell membrane itself, and then translocated into the cytosol. It is believed that EMF-induced rotating water dipoles caused disturbance of the membrane, initiating its deformation and result in an enhanced degree of membrane trafficking via a quasi-exocytosis process.
Thalassospira australica sp. nov. isolated from sea water
Publisher: Springer Science and Business Media LLC
Date: 14-05-2016
DOI: 10.1007/S10482-016-0710-9
Abstract: Two Gram-negative, non-pigmented, motile bacteria were isolated from a sea water s le collected at St. Kilda Beach, Port Philip Bay, Victoria, Australia. The two strains were found to grow between 4 and 40 °C, pH 5-10 and tolerate up to 10 % NaCl. A phylogenetic study, based on a 16S rRNA gene sequence analysis indicated that strains NP 3b2(T) and H 94 belong to the genus Thalassospira. The sequence similarity of the 16S rRNA gene between the two new isolates is 99.8 % and between these strains and all validly named Thalassospira species was found to be in the range of 95-99.4 %. The DNA-DNA relatedness between the two strains was found to be 80.2 %, while relatedness with other validly named species of the genus Thalassospira was between 53 and 65 %. The average nucleotide identity (ANI) and the in silico genome-to-genome distance (GGD) between the two bacteria and T. profundimaris WP0211(T), T. xiamenensis M-5(T), 'T. permensis' NBRC 106175(T) and T. lucentensis QMT2(T) was 76-82 % and 21-25 %, respectively. The results of phylogenetic and genomic analysis, together with physiological and biochemical properties, indicated that the two strains represent a new species of the genus Thalassospira. Based on these data, a new species, Thalassospira australica, is proposed with strain NP 3b2(T) (=KMM 6365(T) = JCM 31222(T)) as the type strain.
The Genus Alteromonas and Related Proteobacteria
Publisher: Springer New York
Date: 2006
Advanced synthetic and hybrid polymer biomaterials derived from inorganic and mixed organic-inorganic sources
Publisher: Elsevier
Date: 2014
Granulosicoccus coccoides sp. nov., isolated from leaves of seagrass (Zostera marina)
Publisher: Microbiology Society
Date: 04-2010
Abstract: A non-pigmented, motile, Gram-negative bacterium, strain Z 271 T , was isolated from the surface of leaves of the seagrass Zostera marina which was collected in Troitza Bay (Sea of Japan, Pacific Ocean). The new isolate grew between 5 °C and 28 °C and was slightly halophilic, tolerating environments containing up to 5 % (w/v) NaCl. Strain Z 271 T was able to degrade Tweens 20, 40 and 80 and partially degrade gelatin, but was unable to degrade casein. Phosphatidylethanolamine (36.9 %) and phosphatidylglycerol (63.1 %) were the predominant phospholipids. The major fatty acids included C 18 : 1 ω 7 c (43.7 %), C 16 : 1 ω 7 c (31.1 %) and C 16 : 0 (16.8 %). The main respiratory quinone was Q-8. The DNA–DNA relatedness value of strain Z 271 T with Granulosicoccus antarcticus IMCC3135 T was 35 %. The G+C content of the DNA of strain Z 271 T was 60.2 mol%. On the basis of phenotypic and genotypic characteristics and 16S rRNA gene sequence analysis, strain Z 271 T represents a novel species of the genus Granulosicoccus for which the name Granulosicoccus coccoides sp. nov. is proposed. The type strain is Z 271 T (=KMM 6014 T =CIP 109923 T ).
Three-dimensional reconstruction of surface nanoarchitecture from two-dimensional datasets
Publisher: Springer Science and Business Media LLC
Date: 10-01-2014
Abstract: The design of biomaterial surfaces relies heavily on the ability to accurately measure and visualize the three-dimensional surface nanoarchitecture of substrata. Here, we present a technique for producing three-dimensional surface models using displacement maps that are based on the data obtained from two-dimensional analyses. This technique is particularly useful when applied to scanning electron micrographs that have been calibrated using atomic force microscopy (AFM) roughness data. The evaluation of four different surface types, including thin titanium films, silicon wafers, polystyrene cell culture dishes and dragonfly wings confirmed that this technique is particularly effective for the visualization of conductive surfaces such as metallic titanium. The technique is particularly useful for visualizing surfaces that cannot be easily analyzed using AFM. The speed and ease with which electron micrographs can be recorded, combined with a relatively simple process for generating displacement maps, make this technique useful for the assessment of the surface topography of biomaterials.
The effect of polyterpenol thin film surfaces on bacterial viability and adhesion
Publisher: MDPI AG
Date: 28-01-2011
DOI: 10.3390/POLYM3010388
The multi-faceted mechano-bactericidal mechanism of nanostructured surfaces
Publisher: Proceedings of the National Academy of Sciences
Date: 26-05-2020
Abstract: The bactericidal action delivered by rigid nanopillar arrays stems from the mechanical rupture of the bacterial cell membrane however, the precise mechanism may be unique to the in idual nanopillar geometries. In this study, we demonstrate that the bactericidal action of highly ordered, high-aspect-ratio nanopillar arrays may be associated with the relative flexibility of the in idual nanopillars and the mechanical energy stored within the nanopillars. We propose that the lateral stretching of the cell membrane and interactions at the cell edge are induced by elastic pillar deformations that occur during bacterial adhesion. The results obtained in this study provide insight into a previously unknown category of mechano-bactericidal mechanism, highlighting another facet to the mechano-bactericidal action of nanostructured surfaces.
Tissue Characterization Using Synchrotron Radiation at 0.7 THz to 10.0 THz with Extended ATR Apparatus Techniques
Publisher: MDPI AG
Date: 31-10-2022
DOI: 10.3390/S22218363
Abstract: The attenuated total reflection (ATR) apparatus, with an added partial reflection artial transmission mode, was used to demonstrate a novel way of characterizing water-based substances at 0.7 to 10.0 THz at the Australian Synchrotron THz-far infrared beamline. The technique utilized a diamond-crystal-equipped ATR to track temperature-dependent changes in reflectance. A “crossover flare” feature in the spectral scan was noted, which appeared to be a characteristic of water and water-dominated compounds. A “quiet zone” feature was also seen, where no temperature-dependent variation in reflectance exists. The variation in these spectral features can be used as a signature for the presence of bound and bulk water. The method can also potentially identify the presence of fats and oils in a biological specimen. The technique requires minimal s le preparation and is non-destructive. The presented method has the promise to provide a novel, real-time, low-preparation, analytical method for investigating biological material, which offers avenues for rapid medical diagnosis and industrial analysis.
Subpicosecond 41.8-nm X-ray laser in the plasma produced by femtosecond laser irradiation of a xenon cluster jet
Publisher: IOP Publishing
Date: 31-12-2012
The Families Hahellaceae and Litoricolaceae
Publisher: Springer Berlin Heidelberg
Date: 2014
The O-chain structure from the LPS of marine halophilic bacterium Pseudoalteromonas carrageenovora-type strain IAM 12662T
Publisher: Elsevier BV
Date: 12-2005
DOI: 10.1016/J.CARRES.2005.09.007
Abstract: The O-chain polysaccharide of the lipopolysaccharide from the halophilic marine bacterium Pseudoalteromonas carrageenovora IAM 12662T was characterized. The structure was studied by means of chemical analysis and 2D NMR spectroscopy of the de-O-acylated lipopolysaccharide and shown to be the following:Col is colitose, 3,6-di-deoxy-L-xylo-hexose.
Specific Electromagnetic Effects of Microwave Radiation on Escherichia coli
Publisher: American Society for Microbiology
Date: 05-2011
DOI: 10.1128/AEM.01899-10
Abstract: The present study investigated the effects of microwave (MW) radiation applied under a sublethal temperature on Escherichia coli . The experiments were conducted at a frequency of 18 GHz and at a temperature below 40°C to avoid the thermal degradation of bacterial cells during exposure. The absorbed power was calculated to be 1,500 kW/m 3 , and the electric field was determined to be 300 V/m. Both values were theoretically confirmed using CST Microwave Studio 3D Electromagnetic Simulation Software. As a negative control, E. coli cells were also thermally heated to temperatures up to 40°C using Peltier plate heating. Scanning electron microscopy (SEM) analysis performed immediately after MW exposure revealed that the E. coli cells exhibited a cell morphology significantly different from that of the negative controls. This MW effect, however, appeared to be temporary, as following a further 10-min elapsed period, the cell morphology appeared to revert to a state that was identical to that of the untreated controls. Confocal laser scanning microscopy (CLSM) revealed that fluorescein isothiocyanate (FITC)-conjugated dextran (150 kDa) was taken up by the MW-treated cells, suggesting that pores had formed within the cell membrane. Cell viability experiments revealed that the MW treatment was not bactericidal, since 88% of the cells were recovered after radiation. It is proposed that one of the effects of exposing E. coli cells to MW radiation under sublethal temperature conditions is that the cell surface undergoes a modification that is electrokinetic in nature, resulting in a reversible MW-induced poration of the cell membrane.
Wavelength-Sensitive Optical Tweezers Using Black-Si Nanospikes for Controlling the Internal Polarity of a Polymer Droplet
Publisher: American Chemical Society (ACS)
Date: 22-12-2022
Against the rules: A marine bacterium, Loktanella rosea, possesses a unique lipopolysaccharide
Publisher: Oxford University Press (OUP)
Date: 21-01-2010
Abstract: Bacteria are an inimitable source of new glyco-structures potentially useful in medicinal and environmental chemistry. Lipopolysaccharides (LPS endotoxins) are the major components of the outer membrane of Gram-negative bacteria being exposed toward the external environment they can undergo structural changes and thus, they often possess peculiar chemical features that allow them to thrive in harsh chemical and physical environments. Marine bacteria have evolved and adapted over millions of years in order to succeed in different environments, finding a niche for their survival characterized by severe physical or chemical parameters. The present work focuses on the structural investigation of the LPS from Loktanella rosea, a marine Gram-negative bacterium. Through chemical analysis, 2D nuclear magnetic resonance and matrix-assisted laser desorption ionization mass spectrometry investigations, a unique LPS carbohydrate backbone has been defined. The lipid A skeleton consists of a trisaccharide backbone lacking the typical phosphate groups and is characterized by two beta-glucosamines and an alpha-galacturonic acid. The core region is built up of three ulosonic acids, with two 3-deoxy-d-manno-oct-2-ulopyranosonic acid residues, one of which is carrying a neuraminic acid. This carbohydrate structure is an exceptional variation from the typical architectural skeleton of endotoxins which consequently implies a very different biosynthesis.
Adsorption of Human Plasma Albumin and Fibronectin onto Nanostructured Black Silicon Surfaces
Publisher: American Chemical Society (ACS)
Date: 10-10-2016
DOI: 10.1021/ACS.LANGMUIR.6B02601
Abstract: The protein adsorption of two human plasma proteins-albumin (Alb) and fibronectin (Fn)-onto synthetic nanostructured bactericidal material-black silicon (bSi) surfaces (that contain an array of nanopillars) and silicon wafer (nonstructured) surfaces-was investigated. The adsorption behavior of Alb and Fn onto two types of substrata was studied using a combination of complementary analytical techniques. A two-step Alb adsorption mechanism onto the bSi surface has been proposed. At low bulk concentrations (below 40 μg/mL), the Alb preferentially adsorbed at the base of the nanopillars. At higher bulk concentrations, the Alb adsorbed on the top of the nanopillars. In the case of Fn, the protein preferentially adsorbed on the top of the nanopillars, irrespective of its bulk concentration.
Fluorescence Colour Control in Perylene‐Labeled Polymer Chains Trapped by Nanotextured Silicon
Publisher: Wiley
Date: 26-01-2022
Abstract: The ability to modulate, tune, and control fluorescence colour has attracted much attention in photonics‐related research fields. Thus far, it has been impossible to achieve fluorescence colour control (FCC) for material with a fixed structure, size, surrounding medium, and concentration. Here, we propose a novel approach to FCC using optical tweezers. We demonstrate an optical trapping technique using nanotextured Si (black‐Si) that can efficiently trap polymer chains. By increasing the laser intensity, the local concentration of perylene‐labelled water‐soluble polymer chains increased inside the trapping potential. Accordingly, the excimer fluorescence of perylene increased while the monomer fluorescence decreased, evidenced by a fluorescence colour change from blue to orange. Using nanostructure‐assisted optical tweezing, we demonstrate control of the relative intensity ratio of fluorescence of the two fluorophores, thus showing remote and reversible FCC of the polymer assembly.
Antibacterial surfaces
Publisher: Springer International Publishing
Date: 2015
Structure of the O-specific polysaccharide from Shewanella japonica KMM 3601 containing 5,7-diacetamido-3,5,7,9-tetradeoxy-d-glycero-d-talo-non-2-ulosonic acid
Publisher: Pleiades Publishing Ltd
Date: 07-2011
Electrospun Nanodiamond-Silk Fibroin Membranes: A Multifunctional Platform for Biosensing and Wound-Healing Applications
Publisher: American Chemical Society (ACS)
Date: 13-10-2020
Use of Synergistic Interactions to Fabricate Transparent and Mechanically Robust Nanohybrids Based on Starch, Non-Isocyanate Polyurethanes, and Cellulose Nanocrystals
Publisher: American Chemical Society (ACS)
Date: 12-10-2020
Comparative genomics of pathogens
Publisher: Springer New York
Date: 03-10-2010
Efficient surface modification of biomaterial to prevent biofilm formation and the attachment of microorganisms
Publisher: Springer Science and Business Media LLC
Date: 18-05-2012
DOI: 10.1007/S00253-012-4144-7
Abstract: Biomaterials play a fundamental role in disease management and the improvement of health care. In recent years, there has been a significant growth in the ersity, function, and number of biomaterials used worldwide. Yet, attachment of pathogenic microorganisms onto biomaterial surfaces remains a significant challenge that substantially undermines their clinical applicability, limiting the advancement of these systems. The emergence and escalating pervasiveness of antibiotic-resistant bacterial strains makes the management of biomaterial-associated nosocomial infections increasingly difficult. The conventional post-operative treatment of implant-caused infections using systemic antibiotics is often marginally effective, further accelerating the extent of antimicrobial resistance. Methods by which the initial stages of bacterial attachment and biofilm formation can be restricted or prevented are therefore sought. The surface modification of biomaterials has the potential to alleviate pathogenic biofouling, therefore preventing the need for conventional antibiotics to be applied.
Biomimetic Nanopillar Silicon Surfaces Rupture Fungal Spores
Publisher: MDPI AG
Date: 09-01-2023
DOI: 10.3390/IJMS24021298
Abstract: The mechano-bactericidal action of nanostructured surfaces is well-documented however, synthetic nanostructured surfaces have not yet been explored for their antifungal properties toward filamentous fungal species. In this study, we developed a biomimetic nanostructured surface inspired by dragonfly wings. A high-aspect-ratio nanopillar topography was created on silicon (nano-Si) surfaces using inductively coupled plasma reactive ion etching (ICP RIE). To mimic the superhydrophobic nature of insect wings, the nano-Si was further functionalised with trichloro(1H,1H,2H,2H-perfluorooctyl)silane (PFTS). The viability of Aspergillus brasiliensis spores, in contact with either hydrophobic or hydrophilic nano-Si surfaces, was determined using a combination of standard microbiological assays, confocal laser scanning microscopy (CLSM), and focused ion beam scanning electron microscopy (FIB-SEM). Results indicated the breakdown of the fungal spore membrane upon contact with the hydrophilic nano-Si surfaces. By contrast, hydrophobised nano-Si surfaces prevented the initial attachment of the fungal conidia. Hydrophilic nano-Si surfaces exhibited both antifungal and fungicidal properties toward attached A. brasisiensis spores via a 4-fold reduction of attached spores and approximately 9-fold reduction of viable conidia from initial solution after 24 h compared to their planar Si counterparts. Thus, we reveal, for the first time, the physical rupturing of attaching fungal spores by biomimetic hydrophilic nanostructured surfaces.
Advanced synthetic polymer biomaterials derived from organic sources
Publisher: Elsevier
Date: 2014
Frontispiz: Fluorescence Colour Control in Perylene‐Labeled Polymer Chains Trapped by Nanotextured Silicon
Publisher: Wiley
Date: 27-02-2022
Intrinsic microtubule GTP-cap dynamics in semi-confined systems: Kinetochore-microtubule interface
Publisher: Springer Science and Business Media LLC
Date: 18-10-2013
The Design of Superhydrophobic Surfaces
Publisher: Elsevier
Date: 2015
Energy levels of ions of silver and rhodium isoelectronic sequences with Z < 86
Publisher: Pleiades Publishing Ltd
Date: 11-2007
Robust and Eco-Friendly Superhydrophobic Starch Nanohybrid Materials with Engineered Lotus Leaf Mimetic Multiscale Hierarchical Structures
Publisher: American Chemical Society (ACS)
Date: 21-07-2021
“Race for the Surface”: Eukaryotic Cells Can Win
Publisher: American Chemical Society (ACS)
Date: 16-08-2016
Abstract: With an aging population and the consequent increasing use of medical implants, managing the possible infections arising from implant surgery remains a global challenge. Here, we demonstrate for the first time that a precise nanotopology provides an effective intervention in bacterial cocolonization enabling the proliferation of eukaryotic cells on a substratum surface, preinfected by both live Gram-negative, Pseudomonas aeruginosa, and Gram-positive, Staphylococcus aureus, pathogenic bacteria. The topology of the model black silicon (bSi) substratum not only favors the proliferation of eukaryotic cells but is biocompatible, not triggering an inflammatory response in the host. The attachment behavior and development of filopodia when COS-7 fibroblast cells are placed in contact with the bSi surface are demonstrated in the dynamic study, which is based on the use of real-time sequential confocal imaging. Bactericidal nanotopology may enhance the prospect for further development of inherently responsive antibacterial nanomaterials for bionic applications such as prosthetics and implants.
Edge and Contrast Enhancement Using Spatially Incoherent Correlation Holography Techniques
Publisher: MDPI AG
Date: 16-06-2021
Abstract: Image enhancement techniques (such as edge and contrast enhancement) are essential for many imaging applications. In incoherent holography techniques such as Fresnel incoherent correlation holography (FINCH), the light from an object is split into two, each of which is modulated differently from one another by two different quadratic phase functions and coherently interfered to generate the hologram. The hologram can be reconstructed via a numerical backpropagation. The edge enhancement procedure in FINCH requires the modulation of one of the beams by a spiral phase element and, upon reconstruction, edge-enhanced images are obtained. An optical technique for edge enhancement in coded aperture imaging (CAI) techniques that does not involve two-beam interference has not been established yet. In this study, we propose and demonstrate an iterative algorithm that can yield from the experimentally recorded point spread function (PSF), a synthetic PSF that can generate edge-enhanced reconstructions when processed with the object hologram. The edge-enhanced reconstructions are subtracted from the original reconstructions to obtain contrast enhancement. The technique has been demonstrated on FINCH and CAI methods with different spectral conditions.
Interaction of Giant Unilamellar Vesicles with the Surface Nanostructures on Dragonfly Wings
Publisher: American Chemical Society (ACS)
Date: 10-01-2019
DOI: 10.1021/ACS.LANGMUIR.8B03470
Abstract: The waxy epicuticle of dragonfly wings contains a unique nanostructured pattern that exhibits bactericidal properties. In light of emerging concerns of antibiotic resistance, these mechano-bactericidal surfaces represent a particularly novel solution by which bacterial colonization and the formation of biofilms on biomedical devices can be prevented. Pathogenic bacterial biofilms on medical implant surfaces cause a significant number of human deaths every year. The proposed mechanism of bactericidal activity is through mechanical cell rupture however, this is not yet well understood and has not been well characterized. In this study, we used giant unilamellar vesicles (GUVs) as a simplified cell membrane model to investigate the nature of their interaction with the surface of the wings of two dragonfly species, Austrothemis nigrescens and Trithemis annulata, sourced from Victoria, Australia, and the Baix Ebre and Terra Alta regions of Catalonia, Spain. Confocal laser scanning microscopy and cryo-scanning electron microscopy techniques were used to visualize the interactions between the GUVs and the wing surfaces. When exposed to both natural and gold-coated wing surfaces, the GUVs were adsorbed on the surface, exhibiting significant deformation, in the process of membrane rupture. Differences between the tensile rupture limit of GUVs composed of 1,2-dioleoyl- sn-glycero-3-phosphocholine and the isotropic tension generated from the internal osmotic pressure were used to indirectly determine the membrane tensions, generated by the nanostructures present on the wing surfaces. These were estimated as being in excess of 6.8 mN m
Microlithographically fabricated bar-coded microarrays
Publisher: SPIE
Date: 22-06-2004
DOI: 10.1117/12.537491
Pheochromocytoma (PC12) Cell Response on Mechanobactericidal Titanium Surfaces
Publisher: MDPI AG
Date: 14-04-2018
DOI: 10.3390/MA11040605
Bacterial Interaction with Graphene Particles and Surfaces
Publisher: InTech
Date: 31-07-2013
DOI: 10.5772/56172
3D printed polarizing grids for IR-THz synchrotron radiation
Publisher: IOP Publishing
Date: 25-01-2018
Energy levels and probabilities of radiative transitions in the Kr IX ion
Publisher: Pleiades Publishing Ltd
Date: 08-2014
Surface Characteristics and Bone Biocompatibility of Cold-Sprayed Porous Titanium on Polydimethylsiloxane Substrates
Publisher: American Chemical Society (ACS)
Date: 22-02-2023
Marinobacter salarius sp. nov. and Marinobacter similis sp. nov., Isolated from Sea Water
Publisher: Public Library of Science (PLoS)
Date: 08-09-2014
Review of the specific effects of microwave radiation on bacterial cells
Publisher: Springer Science and Business Media LLC
Date: 09-08-2012
DOI: 10.1007/S00253-012-4339-Y
Abstract: The aim of the present review was to evaluate the literature suggesting that consideration be given to the existence of specific microwave (MW) effects on prokaryotic microorganisms that is, effects on organisms that cannot be explained by virtue of temperature increases alone. This review considered a range of the reported effects on cellular components including membranes, proteins, enzyme activity as well as cell death. It is concluded that the attribution of such effects to non-thermal mechanisms is not justified due to poor control protocols and because of the possibility that an unmeasurable thermal force, relating to instantaneous temperature (T (i)) that occurs during MW processing, has not been taken into account. However, due to this lack of control over T (i), it also follows that it cannot be concluded that these effects are not 'non-thermal'. Due to this ambiguity, it is proposed that internal 'micro'-thermal effects may occur that are specific to MW radiation, given its inherent unusual energy deposition patterning.
Black-Si as a Photoelectrode
Publisher: MDPI AG
Date: 05-2020
DOI: 10.3390/NANO10050873
Abstract: The fabrication and characterization of photoanodes based on black-Si (b-Si) are presented using a photoelectrochemical cell in NaOH solution. B-Si was fabricated by maskless dry plasma etching and was conformally coated by tens-of-nm of TiO2 using atomic layer deposition (ALD) with a top layer of CoO x cocatalyst deposited by pulsed laser deposition (PLD). Low reflectivity R 5 % of b-Si over the entire visible and near-IR ( λ 2 μ m) spectral range was favorable for the better absorption of light, while an increased surface area facilitated larger current densities. The photoelectrochemical performance of the heterostructured b-Si photoanode is discussed in terms of the n-n junction between b-Si and TiO2.
Polymerization-Induced Phase Segregation and Self-Assembly of Siloxane Additives to Provide Thermoset Coatings with a Defined Surface Topology and Biocidal and Self-Cleaning Properties
Publisher: MDPI AG
Date: 13-11-2019
DOI: 10.3390/NANO9111610
Abstract: In this work, we report on the incorporation of a siloxane copolymer additive, poly((2-phenylethyl) methylsiloxane)-co(1-phenylethyl) methylsiloxane)-co-dimethylsiloxane), which is fully soluble at room temperature, in a rapid-cure thermoset polyester coating formulation. The additive undergoes polymerization-induced phase segregation (PIPS) to self-assemble on the coating surface as discrete discoid nanofeatures during the resin cure process. Moreover, the copolymer facilitates surface co-segregation of titanium dioxide pigment microparticulate present in the coating. Depending on the composition, the coatings can display persistent superhydrophobicity and self-cleaning properties and, surprisingly, the titanium dioxide pigmented coatings that include the siloxane copolymer additive display high levels of antibacterial performance against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria. This antibacterial performance is believed to be associated with the unique surface topology of these coatings, which comprise stimuli-responsive discoid nanofeatures. This paper provides details of the surface morphology of the coatings and how these relates to the antimicrobial properties of the coating.
Frontispiece: Fluorescence Colour Control in Perylene‐Labeled Polymer Chains Trapped by Nanotextured Silicon
Publisher: Wiley
Date: 27-02-2022
The Family Methylocystaceae
Publisher: Springer Berlin Heidelberg
Date: 2014
A new sterilization technique of bovine pericardial biomaterial using microwave radiation
Publisher: Mary Ann Liebert Inc
Date: 09-2009
DOI: 10.1089/TEN.TEC.2008.0350
Abstract: Bioprosthetic valves created from chemically treated natural tissues such as bovine pericardial biomaterial are used as heart valve scaffolds. Methods currently available for sterilization of biomaterial for transplantation include the application of gamma radiation and chemical sterilants. These techniques, however, can be problematic because they can be expensive and lead to a reduction in tissue integrity. Therefore, improved techniques are needed that are cost effective and do not disrupt the physical properties, functionality, and lifespan of the valvular leaflets. This study examined a novel technique using nonthermal microwave radiation that could lead to the inactivation of bacteria in bovine pericardial biomaterial without compromising valve durability. Two common pathogenic species of bacteria, Escherichia coli and Staphylococcus aureus, were used as test microorganisms. Optimized microwave parameters were used to determine whether inactivation of pathogenic bacteria from bovine pericardium could be achieved. In addition, the effect of microwave sterilization on tissue integrity was examined. The mechanical properties (assessed using dynamic mechanical analysis) and tensile strength testing (using a Universal Tensile Tester) as well as thermal analysis (using thermogravimetric analysis and differential scanning calorimetry) indicated that microwave sterilization did not compromise the functionality of bovine pericardial biomaterial. Scanning electron microscopy imaging and cytotoxicity testing also confirmed that the structure and biocompatibility of transplant biomaterial remained unaltered after the sterilization process. Results from the application of this new microwave (MW) sterilization technique to bovine pericardium showed that near-complete inactivation of the contaminant bacteria was achieved. It is concluded that nonthermal inactivation of pathogenic bacteria from bovine pericardial biomaterial could be achieved using microwave radiation.
Dual role of outer epicuticular lipids in determining the wettability of dragonfly wings
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.COLSURFB.2013.01.042
Abstract: Numerous natural surfaces possess superhydrophobicity and self-cleaning properties that would be extremely beneficial when applied in industry. Dragonfly wings are one ex le of such surfaces, and while their general surface structure is known, their precise chemical composition is not. Here, the epicuticular lipids of dragonfly wing membranes were characterized to investigate their significance in contributing to self-cleaning and superhydrophobic properties. After just 10s of lipid extraction using chloroform, the water contact angles exhibited by the wings decreased below the accepted threshold for superhydrophobicity (150°). Infrared spectra collected at the Australian Synchrotron contained characteristic absorption bands of amide, ester and aliphatic hydrocarbons moieties on the wing surfaces, the latter of which was decreased post-extraction with chloroform. GC-MS data analysis revealed that the epicuticular wax components were dominated by n-alkanes with even-numbered carbons, especially n-hexacosane, and palmitic acid. SEM and AFM data analysis conducted on the untreated and chloroform-extracted wing surfaces demonstrated that surface topography changed after extraction the surface nanostructure was progressively lost with extended extraction times. The data presented here indicate that epicuticular lipids contribute not only to self-cleaning and superhydrophobic properties through their inherent hydrophobic nature, but also by forming the physical structure of the wing surface. This knowledge will be extremely valuable for reconstruction of dragonfly wing structures as a biomimetic template.
Winogradskyella exilis sp. nov., isolated from the starfish Stellaster equestris, and emended description of the genus Winogradskyella
Publisher: Microbiology Society
Date: 07-2010
Abstract: A pale-yellowish-pigmented strain, 022-2-26 T , was isolated from a starfish, Stellaster equestris . Cells of strain 022-2-26 T were Gram-negative short rods that were chemo-organotrophic, alkalitolerant and mesophilic. The predominant menaquinone was MK-6. The major cellular fatty acids were iso-C 15 : 0 , iso-C 15 : 1 , C 15 : 0 , iso-C 15 : 0 2-OH and iso-C 17 : 0 3-OH (together representing 87 % of the total fatty acids). The DNA G+C content was 30.1 mol%. A 16S rRNA gene sequence of the isolate was determined and phylogenetic analyses revealed that strain 022-2-26 T formed a robust clade (neighbour-joining algorithm with a bootstrap value of 95 % and parsimony and maximum-likelihood algorithms) with type strains of species in the genus Winogradskyella . The closest phylogenetic neighbour of strain 022-2-26 T was Winogradskyella poriferorum UST030701-295 T (96 % 16S rRNA gene sequence similarity 59 differences between sequences). On the basis of the phenotypic and chemotaxonomic characteristics and the phylogenetic evidence, it is proposed that strain 022-2-26 T represents a novel species, Winogradskyella exilis sp. nov. The type strain is 022-2-26 T (=KMM 6013 T =CIP 109976 T ).
Phenotypic and physiological changes in the phototrophic purple nonsulfur bacterium Rhodopseudomonas palustris transformed with the binary vector pGA482 carrying the cytokinin biosynthesis gene ipt
Publisher: Pleiades Publishing Ltd
Date: 08-2007
Surface characterization of oligonucleotides immobilized on polymer surfaces
Publisher: SPIE
Date: 11-2002
DOI: 10.1117/12.471946
Structure of teichoic acid from the marine proteobacterium Sulfitobacter brevis KMM 6006
Publisher: Springer Science and Business Media LLC
Date: 11-2007
Do bacteria differentiate between degrees of nanoscale surface roughness?
Publisher: Wiley
Date: 26-08-2011
Abstract: Whereas the employment of nanotechnology in electronics and optics engineering is relatively well established, the use of nanostructured materials in medicine and biology is undoubtedly novel. Certain nanoscale surface phenomena are being exploited to promote or prevent the attachment of living cells. However, as yet, it has not been possible to develop methods that completely prevent cells from attaching to solid surfaces, since the mechanisms by which living cells interact with the nanoscale surface characteristics of these substrates are still poorly understood. Recently, novel and advanced surface characterisation techniques have been developed that allow the precise molecular and atomic scale characterisation of both living cells and the solid surfaces to which they attach. Given this additional capability, it may now be possible to define boundaries, or minimum dimensions, at which a surface feature can exert influence over an attaching living organism.This review explores the current research on the interaction of living cells with both native and nanostructured surfaces, and the role that these surface properties play in the different stages of cell attachment.
Highly selective trapping of enteropathogenic E. coli on Fabry-Perot sensor mirrors
Publisher: Elsevier BV
Date: 05-2012
DOI: 10.1016/J.BIOS.2012.03.019
Abstract: Untreated recycled water, such as sewage and graywater, will almost always contain a wide range of agents that are likely to present risks to human health, including chemicals and pathogenic microorganisms. The microbial hazards, such as large numbers of enteric pathogens that can cause gastroenteric illness if ingested, are the main cause of concern for human health. The presence of the enteropathogenic Escherichia coli (EPEC) serotype is of particular concern, as this group of bacteria is responsible for causing severe infant and travelers' diarrhea, gastroenteritis and hemolytic uremic syndrome. A biosensing system based on an optical Fabry-Pérot (FP) cavity, capable of directly detecting the presence of EPEC within 5 min, has been developed using a simple micro-thin double-sided adhesive tape and two semi-transparent FP mirror plates. The system utilizes a poly(methyl methacrylate) (PMMA) or glass substrates sputtered by 40-nm-thick gold thin films serving as FP mirrors. Mirrors have been activated using 0.1M mercaptopropionic acid, influencing an immobilization density of the translocated intimin receptor (TIR) of 100 ng/cm(2). The specificity of recognition was confirmed by exposing TIR functionalized surfaces to four taxonomically related and/or distantly related bacterial strains. It was found that the TIR-functionalized surfaces did not show any bacterial capture for these other bacterial strains within a 15 min incubation period.
Wavelengths of the self-photopumped nickel-like 4f1P1 →4d1P1 X-ray laser transitions
Publisher: MDPI AG
Date: 13-07-2017
DOI: 10.3390/ATOMS5030025
Diversity of experimental designs for the fabrication of antifungal surfaces for the built environment
Publisher: Springer Science and Business Media LLC
Date: 11-03-2021
Bactericidal activity of black silicon
Publisher: Springer Science and Business Media LLC
Date: 26-11-2013
DOI: 10.1038/NCOMMS3838
The complete structure of the core carbohydrate backbone from the LPS of marine halophilic bacterium Pseudoalteromonas carrageenovora type strain IAM 12662T
Publisher: Elsevier BV
Date: 06-2005
DOI: 10.1016/J.CARRES.2005.03.012
Abstract: The complete novel structure of the components of the core oligosaccharide fraction from the LOS of the halophilic marine bacterium Pseudoalteromonas carrageenovora was characterized. The fully de-acylated lipooligosaccharide was studied by means of compositional analysis, matrix-assisted laser desorption/ionization mass spectrometry and complete (1)H and (13)C and (31)P NMR spectroscopy. The core oligosaccharide is composed by a mixture of species differing for the length of the sugar chain and the phosphorylation pattern: [carbohydrate structure] see text. All sugars are D-pyranoses. Hep is L-glycero-D-manno-heptose, Kdo is 3-deoxy-D-manno-oct-2-ulosonic acid, P is phosphate, residues and substituents in italic are not stoichiometrically linked.
Direct Measurement of Temperature Diffusivity of Nanocellulose-Doped Biodegradable Composite Films
Publisher: MDPI AG
Date: 29-07-2020
DOI: 10.3390/MI11080738
Abstract: The thermal properties of novel nanomaterials play a significant role in determining the performance of the material in technological applications. Herein, direct measurement of the temperature diffusivity of nanocellulose-doped starch–polyurethane nanocomposite films was carried out by the micro-contact method. Polymer films containing up to 2 wt%. of nanocellulose were synthesised by a simple chemical process and are biodegradable. Films of a high optical transmittance T≈80% (for a 200 μm thick film), which were up to 44% crystalline, were characterised. Two different modalities of temperature diffusivity based on (1) a resistance change and (2) micro-thermocouple detected voltage modulation caused by the heat wave, were used for the polymer films with cross sections of ∼100 μm thickness. Twice different in-plane α‖ and out-of-plane α⊥ temperature diffusivities were directly determined with high fidelity: α‖=2.12×10−7 m2/s and α⊥=1.13×10−7 m2/s. This work provides an ex le of a direct contact measurement of thermal properties of nanocellulose composite biodegradable polymer films. The thermal diffusivity, which is usually high in strongly interconnected networks and crystals, was investigated for the first time in this polymer nanocomposite.
A study of expression of hypoxanthine and cytokinin-like compounds in the presence of acetosyringone and dexamethasone in phototrophic purple bacteria and their sensor histidine kinases: Biochemical and computer analysis
Publisher: Pleiades Publishing Ltd
Date: 10-2006
Biological Interactions with Superhydrophobic Surfaces
Publisher: Elsevier
Date: 2015
Distribution of Saprophytic Bacteria in the Atomic Submarine Accident Zone in Chazhma Bay, Sea of Japan
Publisher: Springer Science and Business Media LLC
Date: 03-2005
The Effect of Coatings and Nerve Growth Factor on Attachment and Differentiation of Pheochromocytoma Cells
Publisher: MDPI AG
Date: 31-12-2017
DOI: 10.3390/MA11010060
Structure of an acidic polysaccharide from the marine bacterium Pseudoalteromonas aliena type strain KMM 3562T containing two residues of l-serine in the repeating unit
Publisher: Elsevier BV
Date: 06-2005
DOI: 10.1016/J.CARRES.2005.03.013
Abstract: The structure of an acidic polysaccharide from Pseudoalteromonas aliena type strain KMM 3562(T) has been elucidated. The polysaccharide was studied by component analysis, (1)H and (13)C NMR spectroscopy, including 2D NMR experiments. A (1)H, (13)C band-selective constant-time heteronuclear multiple-bond connectivity experiment was used to determine amide linkages, between serine and uronic acid (UA) residues, via (3)J(H,C) correlations between Ser-alphaH and UA-C-6. It was found that the polysaccharide consists of pentasaccharide repeating units with the following structure: [carbohydrate structure] see text.
Modifications to surface chemistry and nanotopography of poly(ethylene terephthalate) by marine bacteria
Publisher: IEEE
Date: 02-2010
Effect of brown algae metabolites on the synthesis of O-glycosyl hydrolases by bacteria degrading the thallus of Fucus evanescens
Publisher: Pleiades Publishing Ltd
Date: 05-2012
Functional nanomaterials, synergisms, and biomimicry for environmentally benign marine antifouling technology
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1MH01103K
Abstract: This review outlines recent progress and strategies for highly efficient, environmentally-friendly marine antifouling technology based on nanomaterials and nanocomposites, as well as synergistic and biomimetic approaches.
Visitors' wayfinding strategies and navigational aids in unfamiliar urban environment
Publisher: Informa UK Limited
Date: 12-2019
Salegentibacter flavus sp. nov.
Publisher: Microbiology Society
Date: 03-2006
Abstract: A yellow-pigmented, non-motile, Gram-negative bacterium, designated Fg 69 T , was isolated from a sediment s le collected in Chazhma Bay (Sea of Japan). The novel organism grew at 10–35 °C, was neutrophilic and required 3–10 % NaCl for optimal growth. Strain Fg 69 T was able to degrade starch and to hydrolyse gelatin and Tween 80 weakly but not casein or agar. Predominant cellular fatty acids comprised n-C 15 and n-C 16 branched-chain and straight-chain saturated and unsaturated fatty acids, including iso-C 15 : 0 (5 %), anteiso-C 15 : 0 (11 %), C 15 : 0 (9 %), iso-C 15 : 1 (5 %), iso-C 16 : 0 (8 %), C 16 : 0 (5 %) and C 16 : 1 ω 7 (5 %) and iso- and anteiso-branched 2-OH and 3-OH C 15 : 0 to C 17 : 0 fatty acids (26 % in total). The G+C content of the DNA was 40·4 mol%. 16S rRNA gene sequence data indicated that strain Fg 69 T belonged to the genus Salegentibacter but was distinct from recognized Salegentibacter species (94–95 % sequence similarity). Based on these results, a novel species, Salegentibacter flavus sp. nov., is proposed. The type strain is Fg 69 T (=KMM 6000 T =CIP 107843 T ).
Superhydrophobicity – An Introductory Review
Publisher: Elsevier
Date: 2015
Double-Locus Sequence Typing Using porA and peb1A for Epidemiological Studies of Campylobacter jejuni
Publisher: Mary Ann Liebert Inc
Date: 03-2014
Abstract: C ylobacter jejuni is the leading cause of foodborne bacterial gastroenteritis worldwide. Bacterial typing schemes play an important role in epidemiological investigations to trace the source and route of transmission of the infectious agent by identifying outbreak and differentiating among sporadic infections. In this study, a double-locus sequence typing (DLST) scheme for C. jejuni based on concatenated partial sequences of porA and peb1A genes is proposed. The DLST scheme was validated using 50 clinical and environmental C. jejuni strains isolated from human (C5, H, H15-H19), chicken (CH1-CH15), water (W2-W17), and ovine s les (OV1-OV6). The scheme was found to be highly discriminatory (discrimination index [DI]=0.964) and epidemiologically concordant based on C. jejuni strains studied. The DLST showed discriminatory power above 0.95 and excellent congruence to multilocus sequence typing and can be recommended as a rapid and low-cost typing scheme for epidemiological investigation of C. jejuni. It is suggested that the DLST scheme is suitable for identification of outbreak strains and differentiation of the sporadic infection strains.
High-spatial-resolution mapping of superhydrophobic cicada wing surface chemistry using infrared microspectroscopy and infrared imaging at two synchrotron beamlines
Publisher: International Union of Crystallography (IUCr)
Date: 22-03-2013
DOI: 10.1107/S0909049513004056
Abstract: The wings of some insects, such as cicadae, have been reported to possess a number of interesting and unusual qualities such as superhydrophobicity, anisotropic wetting and antibacterial properties. Here, the chemical composition of the wings of the Clanger cicada ( Psaltoda claripennis ) were characterized using infrared (IR) microspectroscopy. In addition, the data generated from two separate synchrotron IR facilities, the Australian Synchrotron Infrared Microspectroscopy beamline (AS-IRM) and the Synchrotron Radiation Center (SRC), University of Wisconsin-Madison, IRENI beamline, were analysed and compared. Characteristic peaks in the IR spectra of the wings were assigned primarily to aliphatic hydrocarbon and amide functionalities, which were considered to be an indication of the presence of waxy and proteinaceous components, respectively, in good agreement with the literature. Chemical distribution maps showed that, while the protein component was homogeneously distributed, a significant degree of heterogeneity was observed in the distribution of the waxy component, which may contribute to the self-cleaning and aerodynamic properties of the cicada wing. When comparing the data generated from the two beamlines, it was determined that the SRC IRENI beamline was capable of producing higher-spatial-resolution distribution images in a shorter time than was achievable at the AS-IRM beamline, but that spectral noise levels per pixel were considerably lower on the AS-IRM beamline, resulting in more favourable data where the detection of weak absorbances is required. The data generated by the two complementary synchrotron IR methods on the chemical composition of cicada wings will be immensely useful in understanding their unusual properties with a view to reproducing their characteristics in, for ex le, industry applications.
Features of the Emission Spectra of Ni-Like Ions. Application to Calculating the Wavelengths of Self-Photo-Pumped X-Ray Lasers
Publisher: Pleiades Publishing Ltd
Date: 08-2018
Protein immobilisation on micro/nanostructures fabricated by laser microablation
Publisher: Elsevier BV
Date: 12-2010
DOI: 10.1016/J.BIOS.2010.07.044
Abstract: The performance of biomedical microdevices requires the accurate control of the biomolecule concentration on the surface, as well as the preservation of their bioactivity. This desideratum is even more critical for proteins, which present a significant propensity for surface-induced denaturation, and for microarrays, which require high multiplexing. We have previously proposed a method for protein immobilisation on micro/nanostructures fabricated via laser ablation of a thin metal layer deposited on a transparent polymer. This study investigates the relationship between the properties of the micro/nanostructured surface, i.e., topography and physico-chemistry, and protein immobilisation, for five, molecularly different proteins, i.e., lysozyme, myoglobin, α-chymotrypsin, human serum albumin, and human immunoglobulin. Protein immobilisation on microstructures has been characterised using quantitative fluorescence measurements and atomic force microscopy. It has been found that the sub-micrometer-level, combinatorial nature of the microstructure translates in a 3-10-fold lification of protein adsorption, as compared to flat, chemically homogenous polymeric surfaces. This lification is more pronounced for smaller proteins, as they can capitalize better on the newly created surface and variability of the nano-environments.
Outsmarting superbugs: bactericidal activity of nanostructured titanium surfaces against methicillin- and gentamicin-resistant Staphylococcus aureus ATCC 33592
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TB00102F
Abstract: The colonisation of biomaterial surfaces by pathogenic bacteria is a significant issue of concern, particularly in light of the rapid rise of antibiotic resistance.
Erythrobacter vulgaris sp. nov., a novel organism isolated from the marine invertebrates
Publisher: Elsevier BV
Date: 03-2005
DOI: 10.1016/J.SYAPM.2004.11.001
Abstract: Four yellow-pigmented, gram-negative, chemoorganotrophic aerobic bacteria were isolated from starfish Stellaster equestris (strains 022-2-10T, 022-2-9, and 022-2-12) and soft coral (unidentified species) (strain 022-4-7) collected in the South China Sea. 16S rRNA gene sequence-based analyses of the new organisms revealed that Erythrobacter spp. were the closest relatives and shared the highest similarity of 98.7% to E. citreus, 98.5% to E. flavus, 97.9% to E. litoralis and 97.6% to E. longus. The novel organisms were tolerant to 3-6% NaCl, grew between 10 degrees C and 40 degrees C, and were not able to degrade gelatin, casein, and agar, while degraded Tween 80. Two strains (022-2-9 and 022-2-12) could weakly degrade starch. All strains produced a large pool of carotenoids and did not have Bacteriochlorophyll a. Phosphatidylethanolamine (30-36%), phosphatidylglycerol (39-46%), and phosphatidylcholine (21-27%) were the predominant phospholipids. Sphingoglycolipid was not detected. The major fatty acids were 16:0 (6-11%), 16:1omega7 (12-15%), and 18:1omega7 (46-49%). The two-hydroxy fatty acids, 13:0-2OH, 14:0-2OH, 15:0-2OH, 16:0-2OH were also present. The G + C content of the DNAs ranged from 61 to 62 mol%. The level of DNA similarity among four strains was conspecific and ranged from 94% to 98%. Even though new strains and other species of the genus had rather high level of 16S rRNA gene sequence similarities, DNA-DNA hybridization experiments showed only 33-39% of binding with the DNA of the type strains. On the basis of these results and the significant differences demonstrated in the phenotypic and chemotaxonomic characteristics, it is suggested that the new organisms be classified as a novel species the name Erythrobacter vulgaris sp. nov. is proposed. The type strain is 022-2-10T (= KMM 3465T = CIP 107841T).
Introduction to antibacterial surfaces
Publisher: Springer International Publishing
Date: 2015
Natural antibacterial surfaces
Publisher: Springer International Publishing
Date: 2015
Oceanimonas smirnovii sp. nov., a novel organism isolated from the Black Sea
Publisher: Elsevier BV
Date: 03-2005
DOI: 10.1016/J.SYAPM.2004.11.002
Abstract: A slightly creamy, melanogenic, gram-negative, aerobic bacterium was isolated from seawater s le collected in the Karadag Natural Reserve of the Eastern Crimea, the Black Sea. The novel organism was chemoorganotrophic, had no obligate requirement in NaCl, tolerated to 12% NaCl, grew between 10 and 45 degrees C, was slightly alkaliphilic, and was not able to degrade starch, gelatin, agar, and Tween 80. 16S rRNA gene sequence-based analyses of the new organism revealed that Oceanimonas doudoroffii ATCC 27123T, Oceanimonas baumanii ATCC 700832T, and Oceanisphaera litoralis DSM 15406T were the closest relatives (similarity around 97%-96%). The G + C content of the DNA of the strain 31-13T was 55.5mol%. Phosphatidylethanolamine (49.0%), phosphatidylglycerol (41.8%), and diphosphatidylglycerol (9.2%) were the predominant phospholipids. The major fatty acids were 16:0 (24.1%), 16:1omega7 (40.3%), and 18:1omega7 (29.2%). On the basis of the significant differences demonstrated in the phenotypic and chemotaxonomic characteristics, it is suggested that the bacterium be classified as a novel species the name Oceanimonas smirnovii sp. nov. is proposed. The type strain is 31-13T (UCM B-11076T = LMG 22147T = ATCC BAA-899T).
Designing antibacterial surfaces for biomedical implants
Publisher: Springer International Publishing
Date: 2015
Plasma-assisted surface modification of organic biopolymers to prevent bacterial attachment
Publisher: Elsevier BV
Date: 05-2011
DOI: 10.1016/J.ACTBIO.2010.12.024
Abstract: Despite many synthetic biomaterials having physical properties that are comparable or even superior to those of natural body tissues, they frequently fail due to the adverse physiological reactions they cause within the human body, such as infection and inflammation. The surface modification of biomaterials is an economical and effective method by which biocompatibility and biofunctionality can be achieved while preserving the favorable bulk characteristics of the biomaterial, such as strength and inertness. Amongst the numerous surface modification techniques available, plasma surface modification affords device manufacturers a flexible and environmentally friendly process that enables tailoring of the surface morphology, structure, composition, and properties of the material to a specific need. There are a vast range of possible applications of plasma modification in biomaterial applications, however, the focus of this review paper is on processes that can be used to develop surface morphologies and chemical structures for the prevention of adhesion and proliferation of pathogenic bacteria on the surfaces of in-dwelling medical devices. As such, the fundamental principles of bacterial cell attachment and biofilm formation are also discussed. Functional organic plasma polymerised coatings are also discussed for their potential as biosensitive interfaces, connecting inorganic/metallic electronic devices with their physiological environments.
Wavelengths of the 4d–4p, 0–1 transitions of X-ray lasers in Ni-like ions with Z ≤ 79
Publisher: Pleiades Publishing Ltd
Date: 04-2015
The idiosyncratic self-cleaning cycle of bacteria on regularly arrayed mechano-bactericidal nanostructures
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NR05923G
Abstract: Bacterial cells are lysed when they attach onto regularly arrayed silicon nanopillars. Following cell lysis, the cell debris detaches from the surface and is released back into the immediate environment which allows for restored bactericidal activity of the substratum.
Graphene Induces Formation of Pores That Kill Spherical and Rod-Shaped Bacteria
Publisher: American Chemical Society (ACS)
Date: 21-07-2015
Abstract: Pristine graphene, its derivatives, and composites have been widely reported to possess antibacterial properties. Most of the studies simulating the interaction between bacterial cell membranes and the surface of graphene have proposed that the graphene-induced bacterial cell death is caused either by (1) the insertion of blade-like graphene-based nanosheets or (2) the destructive extraction of lipid molecules by the presence of the lipophilic graphene. These simulation studies have, however, only take into account graphene-cell membrane interactions where the graphene is in a dispersed form. In this paper, we report the antimicrobial behavior of graphene sheet surfaces in an attempt to further advance the current knowledge pertaining to graphene cytotoxicity using both experimental and computer simulation approaches. Graphene nanofilms were fabricated to exhibit different edge lengths and different angles of orientation in the graphene sheets. These substrates were placed in contact with Pseudomonas aeruginosa and Staphylococcus aureus bacteria, where it was seen that these substrates exhibited variable bactericidal efficiency toward these two pathogenic bacteria. It was demonstrated that the density of the edges of the graphene was one of the principal parameters that contributed to the antibacterial behavior of the graphene nanosheet films. The study provides both experimental and theoretical evidence that the antibacterial behavior of graphene nanosheets arises from the formation of pores in the bacterial cell wall, causing a subsequent osmotic imbalance and cell death.
Energy levels in Ag-like (4d104f, 4d105ℓ (ℓ = 0-3)), Pd-like (4d94f [J = 1], 4d95p [J = 1], 4d95f [J = 1]), and Rh-like (4d9 [J = 5/2, 3/2]) ions with Z ≤ 86
Publisher: Elsevier BV
Date: 11-2009
Simulations of Protein Adsorption on Nanostructured Surfaces
Publisher: Springer Science and Business Media LLC
Date: 18-03-2019
DOI: 10.1038/S41598-019-40920-Z
Abstract: Recent technological advances have allowed the development of a new generation of nanostructured materials, such as those displaying both mechano-bactericidal activity and substrata that favor the growth of mammalian cells. Nanomaterials that come into contact with biological media such as blood first interact with proteins, hence understanding the process of adsorption of proteins onto these surfaces is highly important. The Random Sequential Adsorption (RSA) model for protein adsorption on flat surfaces was modified to account for nanostructured surfaces. Phenomena related to the nanofeature geometry have been revealed during the modelling process e.g., convex geometries can lead to lower steric hindrance between particles, and hence higher degrees of surface coverage per unit area. These properties become more pronounced when a decrease in the size mismatch between the proteins and the surface nanostructures occurs. This model has been used to analyse the adsorption of human serum albumin (HSA) on a nano-structured black silicon (bSi) surface. This allowed the Blocking Function (the rate of adsorption) to be evaluated. The probability of the protein to adsorb as a function of the occupancy was also calculated.
Exposure to high-frequency electromagnetic field triggers rapid uptake of large nanosphere clusters by pheochromocytoma cells
Publisher: Informa UK Limited
Date: 12-2018
DOI: 10.2147/IJN.S183767
Radiative transition probabilities in ions of the silver isoelectronic sequence
Publisher: Pleiades Publishing Ltd
Date: 07-2009
High Aspect Ratio Nanostructures Kill Bacteria via Storage and Release of Mechanical Energy.
Publisher: American Chemical Society (ACS)
Date: 31-05-2018
Abstract: The threat of a global rise in the number of untreatable infections caused by antibiotic-resistant bacteria calls for the design and fabrication of a new generation of bactericidal materials. Here, we report a concept for the design of antibacterial surfaces, whereby cell death results from the ability of the nanofeatures to deflect when in contact with attaching cells. We show, using three-dimensional transmission electron microscopy, that the exceptionally high aspect ratio (100-3000) of vertically aligned carbon nanotubes (VACNTs) imparts extreme flexibility, which enhances the elastic energy storage in CNTs as they bend in contact with bacteria. Our experimental and theoretical analyses demonstrate that, for high aspect ratio structures, the bending energy stored in the CNTs is a substantial factor for the physical rupturing of both Gram-positive and Gram-negative bacteria. The highest bactericidal rates (99.3% for Pseudomonas aeruginosa and 84.9% for Staphylococcus aureus) were obtained by modifying the length of the VACNTs, allowing us to identify the optimal substratum properties to kill different types of bacteria efficiently. This work highlights that the bactericidal activity of high aspect ratio nanofeatures can outperform both natural bactericidal surfaces and other synthetic nanostructured multifunctional surfaces reported in previous studies. The present systems exhibit the highest bactericidal activity of a CNT-based substratum against a Gram-negative bacterium reported to date, suggesting the possibility of achieving close to 100% bacterial inactivation on VACNT-based substrata.
Current perspectives on the development of virucidal nano surfaces
Publisher: Elsevier BV
Date: 10-2023
The Evolution of Silica Nanoparticle-polyester Coatings on Surfaces Exposed to Sunlight
Publisher: MyJove Corporation
Date: 11-10-2016
DOI: 10.3791/54309
Mechano-bactericidal actions of nanostructured surfaces
Publisher: Springer Science and Business Media LLC
Date: 17-08-2020
Genome Sequence of “Thalassospira australica” NP3b2 T Isolated from St. Kilda Beach, Tasman Sea
Publisher: American Society for Microbiology
Date: 24-12-2014
Abstract: Here, we present the draft genome of “ Thalassospira australica ” NP3b2 T , a potential poly(ethylene terephthalate) (PET) plastic biodegrader. This genomic information will enhance information on the genetic basis of metabolic pathways for the degradation of PET plastic.
Detection of coccoid forms ofSulfitobacter mediterraneususing atomic force microscopy
Publisher: Oxford University Press (OUP)
Date: 09-2002
DOI: 10.1111/J.1574-6968.2002.TB11343.X
Abstract: The adhesion of the marine alpha-Proteobacteria Sulfitobacter pontiacus, Sulfitobacter mediterraneus, Sulfitobacter brevis, and Staleya guttiformis to a poly(tert-butyl methacrylate) (PtBMA) polymeric surface generates unusual cell morphological peculiarities following attachment. While the type strains S. pontiacus and S. brevis failed to attach to PtBMA, the vegetative cells of type strain S. mediterraneus underwent morphological conversion into coccoid forms during the attachment over an incubation period of 24-72 h. Type strain St. guttiformis cells formed a multilayered biofilm on the PtBMA surface, presumably facilitated by bacterial production of extracellular polysaccharides. The attachment behavior and fine structure of these coccoid forms have been described using atomic force microscopy. The impact of polymeric surfaces of defined hydrophobicity on the formation of coccoid bodies is discussed.
18 GHz electromagnetic field induces permeability of Gram-positive cocci
Publisher: Springer Science and Business Media LLC
Date: 16-06-2015
DOI: 10.1038/SREP10980
Abstract: The effect of electromagnetic field (EMF) exposures at the microwave (MW) frequency of 18 GHz, on four cocci, Planococcus maritimus KMM 3738, Staphylococcus aureus CIP 65.8 T , S. aureus ATCC 25923 and S. epidermidis ATCC 14990 T , was investigated. We demonstrate that exposing the bacteria to an EMF induced permeability in the bacterial membranes of all strains studied, as confirmed directly by transmission electron microscopy (TEM) and indirectly via the propidium iodide assay and the uptake of silica nanospheres. The cells remained permeable for at least nine minutes after EMF exposure. It was shown that all strains internalized 23.5 nm nanospheres, whereas the internalization of the 46.3 nm nanospheres differed amongst the bacterial strains ( S. epidermidis ATCC 14990 T ~ 0% Staphylococcus aureus CIP 65.8 T S. aureus ATCC 25923, ~40% Planococcus maritimus KMM 3738, ~80%). Cell viability experiments indicated that up to 84% of the cells exposed to the EMF remained viable. The morphology of the bacterial cells was not altered, as inferred from the scanning electron micrographs, however traces of leaked cytosolic fluids from the EMF exposed cells could be detected. EMF-induced permeabilization may represent an innovative, alternative cell permeability technique for applications in biomedical engineering, cell drug delivery and gene therapy.
3D printed gratings: IR-THz applications
Publisher: OSA
Date: 2018
Formosa
Publisher: Wiley
Date: 14-09-2015
DOI: 10.1002/9781118960608.GBM00313
Abstract: For.mo'sa. L. fem. adj. (used as a substantive) Formosa beautiful, finely formed. Bacteroidetes / Flavobacteriia / Flavobacteriales / Flavobacteriaceae / Formosa Rod‐shaped cells with slightly irregular sides and pointed ends, approx. 0.8–1.8 × 0.4–0.9 µm. Cells have gliding motility . Buds may be produced . Do not form endospores or resting stages . Gram‐stain‐negative . Poly‐β‐hydroxybutyrate is not accumulated as an intracellular reserve product. An arginine dihydrolase system is not present. Aerobic however, anaerobic growth can occur on D ‐glucose by anaerobic respiration with nitrate. Chemo‐organotrophic. Positive for oxidase, catalase, and alkaline phosphatase. May require Na + for growth. Agar hydrolysis differs among species. Produce non‐diffusible carotenoid pigments. Flexirubin pigments are not detected. Isolated from marine habitats of the North Pacific. DNA G + C content ( mol %): 34–36. Type species : Formosa algae Ivanova, Alexeeva, Flavier, Wright, Zhukova, Gorshkova, Mikhailov, Nicolau and Christen 2004, 707 VP emend. Nedashkovskaya, Kim, Vancanneyt, Snauwaert, Lysenko, Rohde, Frolova, Zhukova, Mikhailov, Bae, Oh and Swings 2006d, 161.
Surface topographical factors influencing bacterial attachment
Publisher: Elsevier BV
Date: 11-2012
DOI: 10.1016/J.CIS.2012.06.015
Abstract: Substratum surface roughness is known to be one of the key factors in determining the extent of bacterial colonization. Understanding the way by which the substratum topography, especially at the nanoscale, mediates bacterial attachment remains ambiguous at best, despite the volume of work available on the topic. This is because the vast majority of bacterial attachment studies do not perform comprehensive topographical characterization analyses, and typically consider roughness parameters that describe only one aspect of the surface topography. The most commonly reported surface roughness parameters are average and root mean square (RMS) roughness (R(a) and R(q) respectively), which are both measures of the typical height variation of the surface. They offer no insights into the spatial distribution or shape of the surface features. Here, a brief overview of the current state of research on topography-mediated bacterial adhesion is presented, as well as an outline of the suite of roughness characterization parameters that are available for the comprehensive description of the surface architecture of a substratum. Finally, a set of topographical parameters is proposed as a new standard for surface roughness characterization in bacterial adhesion studies to improve the likelihood of identifying direct relationships between substratum topography and the extent of bacterial adhesion.
Mutation is the main driving force in the diversification of the Vibrio splendidus clade
Publisher: Japanese Society of Microbial Ecology
Date: 2009
Abstract: The Vibrio splendidus clade is the biggest in Vibrionales composed of 11 described species (25). Diversification of these species may have occurred 260 million years ago. The main driving forces of speciation in this clade have never been studied. Population biological parameters (population base recombination rate (ρ), population base mutation rate (θ), and index of association (Ia)) were determined among 16 strains of 9 defined species in the Splendidus cluster. A comparison of in idual gene phylogeny indicated significant incongruence in tree topology, which suggests the occurrence of recombination between species. Homologous recombination between species was detected at four loci. However, the mutation rate θ was higher than the recombination rate ρ, suggesting that mutation is the main driving force in the ersification of V. splendidus-related species.
Nanoscale Surface Roughness Influences Candida albicans Biofilm Formation
Publisher: American Chemical Society (ACS)
Date: 09-12-2020
Abstract: The microbial contamination of surfaces presents a significant challenge due to the adverse effects associated with biofilm formation, particularly on implantable devices. Here, the attachment and biofilm formation of the opportunistic human pathogen,
The Outer Membrane of the Marine Gram‐Negative Bacterium Alteromonas addita is Composed of a Very Short‐Chain Lipopolysaccharide with a High Negative Charge Density
Publisher: Wiley
Date: 13-02-2007
Abstract: The complete structure of the lipopolysaccharide isolated from the Gram‐negative marine bacterium Alteromonas addita , type strain KMM 3600 T = R10SW13 T , has been elucidated by means of a combined chemical approach and state‐of‐the‐art NMR and MS analyses. Isolation and characterisation of the lipid A moiety and the core oligosaccharide were pursued separately after either acid or alkaline treatment of the lipopolysaccharide. The structure detected was identified as a novel, highly negatively charged, deep‐rough lipopolysaccharide in which a trisaccharide subunit is connected to a typical lipid A glucosamine backbone. Within the core oligosaccharide, a phosphodiester bridge connects a glucose unit to a heptose residue.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Structural Analysis of the Deep Rough Lipopolysaccharide from Gram Negative Bacterium Alteromonas macleodii ATCC 27126T: The First Finding of β‐Kdo in the Inner Core of Lipopolysacch
Publisher: Wiley
Date: 20-09-2006
Controlling production of brominated cyclic depsipeptides by Pseudoalteromonas maricaloris KMM 636T
Publisher: Oxford University Press (OUP)
Date: 04-2005
How calcium controls microtubule anisotropic phase formation in the presence of microtubule-associated proteins in vitro
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.BBRC.2009.02.028
Abstract: Here we show a new effect of Ca2+ on microtubule morphology: Ca2+ can cause smooth curving of microtubules in the presence of microtubule-associated proteins (MAPs). In vitro, microtubules self-organize, forming complex dissipative structures. Such structures may be strongly affected by relatively weak external factors. A factor such as Ca2+ potentially influences spatiotemporal patterns of microtubule assembly, but the dynamics are unclear. We tested Ca2+ effects on microtubule formation. Using EM, microtubule length, curvature, and alignment and were measured in two systems: 2 mg/ml microtubule protein containing MAPs and 1 mM EGTA with and without 1 mM Ca2+. The two systems were then tested using light scattering. In low Ca2+, a birefringent microtubular pattern is seen, increasing with polymerization. When 1 mM Ca2+ is added to the solution, anisotropic phase is prevented without microtubule disruption. This demonstrates an additional mechanism by which Ca2+ can alter the dynamics and morphology of microtubules.
The Structural Diversity of Carbohydrate Antigens of Selected Gram-Negative Marine Bacteria
Publisher: MDPI AG
Date: 14-10-2011
DOI: 10.3390/MD9101914
Switchable Dual-Function and Bioresponsive Materials to Control Bacterial Infections
Publisher: American Chemical Society (ACS)
Date: 10-06-2019
Abstract: The colonization of undesired bacteria on the surface of devices used in biomedical and clinical applications has become a persistent problem. Different types of single-function (cell resistance or bactericidal) bioresponsive materials have been developed to cope with this problem. Even though these materials meet the basic requirements of many biomedical and clinical applications, dual-function (cell resistance and biocidal) bioresponsive materials with superior design and function could be better suited for these applications. The past few years have witnessed the emergence of a new class of dual-function materials that can reversibly switch between cell-resistance and biocidal functions in response to external stimuli. These materials are finding increased applications in biomedical devices, tissue engineering, and drug-delivery systems. This review highlights the recent advances in design, structure, and fabrication of dual-function bioresponsive materials and discusses translational challenges and future prospects for research involving these materials.
Programmed Death of Injured
Publisher: American Chemical Society (ACS)
Date: 18-01-2022
DOI: 10.1021/ACS.NANOLETT.1C04243
Abstract: Mechano-bactericidal surfaces deliver lethal effects to contacting bacteria. Until now, cell death has been attributed to the mechanical stress imparted to the bacterial cell envelope by the surface nanostructures however, the process of bacterial death encountering nanostructured surfaces has not been fully illuminated. Here, we perform an in-depth investigation of the mechano-bactericidal action of black silicon (bSi) surfaces toward Gram-negative bacteria
Inner-shell chemical shift of DNA/RNA bases and inheritance from their parent purine and pyrimidine
Publisher: International Union of Crystallography (IUCr)
Date: 03-10-2008
Polycrystalline Diamond Coating of Additively Manufactured Titanium for Biomedical Applications
Publisher: American Chemical Society (ACS)
Date: 22-02-2018
Abstract: Additive manufacturing using selective laser melted titanium (SLM-Ti) is used to create bespoke items across many erse fields such as medicine, defense, and aerospace. Despite great progress in orthopedic implant applications, such as for "just in time" implants, significant challenges remain with regards to material osseointegration and the susceptibility to bacterial colonization on the implant. Here, we show that polycrystalline diamond coatings on these titanium s les can enhance biological scaffold interaction improving medical implant applicability. The highly conformable coating exhibited excellent bonding to the substrate. Relative to uncoated SLM-Ti, the diamond coated s les showed enhanced mammalian cell growth, enriched apatite deposition, and reduced microbial S. aureus activity. These results open new opportunities for novel coatings on SLM-Ti devices in general and especially show promise for improved biomedical implants.
PC 12 Pheochromocytoma Cell Response to Super High Frequency Terahertz Radiation from Synchrotron Source
Publisher: MDPI AG
Date: 31-01-2019
Abstract: High frequency (HF) electromagnetic fields (EMFs) have been widely used in many wireless communication devices, yet within the terahertz (THz) range, their effects on biological systems are poorly understood. In this study, electromagnetic radiation in the range of 0.3–19.5 × 1012 Hz, generated using a synchrotron light source, was used to investigate the response of PC 12 neuron-like pheochromocytoma cells to THz irradiation. The PC 12 cells remained viable and physiologically healthy, as confirmed by a panel of biological assays however, exposure to THz radiation for 10 min at 25.2 ± 0.4 °C was sufficient to induce a temporary increase in their cell membrane permeability. High-resolution transmission electron microscopy (TEM) confirmed cell membrane permeabilization via visualisation of the translocation of silica nanospheres (d = 23.5 ± 0.2 nm) and their clusters (d = 63 nm) into the PC 12 cells. Analysis of scanning electron microscopy (SEM) micrographs revealed the formation of atypically large (up to 1 µm) blebs on the surface of PC 12 cells when exposed to THz radiation. Long-term analysis showed no substantial differences in metabolic activity between the PC 12 cells exposed to THz radiation and untreated cells however, a higher population of the THz-treated PC 12 cells responded to the nerve growth factor (NGF) by extending longer neurites (up to 0–20 µm) compared to the untreated PC12 cells (up to 20 µm). These findings present implications for the development of nanoparticle-mediated drug delivery and gene therapy strategies since THz irradiation can promote nanoparticle uptake by cells without causing apoptosis, necrosis or physiological damage, as well as provide a deeper fundamental insight into the biological effects of environmental exposure of cells to electromagnetic radiation of super high frequencies.
Loktanella agnita sp. nov. and Loktanella rosea sp. nov., from the north-west Pacific Ocean
Publisher: Microbiology Society
Date: 09-2005
Abstract: One whitish and four pinkish strains of Gram-negative, non-motile, aerobic bacteria were isolated from sea-water and sediment s les collected in Chazhma Bay (Sea of Japan, Pacific Ocean). Analysis of 16S rRNA gene sequences revealed that these strains belonged to the ‘ Alphaproteobacteria ’, having highest sequence similarity of about 94–97 % with species of the genus Loktanella . None of the strains degraded gelatin, casein, chitin, agar, DNA or starch and they had limited ability to utilize carbon sources. The four pinkish strains, Fg36 T , Fg1, Fg116 and Fg117, degraded Tween 80. Sea-water strain R10SW5 T grew at 3–6 % NaCl and a temperature range of 8–35 °C, whilst strains Fg36 T , Fg1, Fg116 and Fg117 grew at NaCl concentrations of 1–12 % and a temperature range of 4–35 °C. Phosphatidylglycerol (58/79 %), diphosphatidylglycerol (11/6 %) and phosphatidylcholine (28/22 %) were the major phospholipids. The predominant fatty acids were 16 : 0 (12·2/8·6 %) and 18 : 1 ω 7 (76·6/68·4 %). The DNA G+C content of strain R10SW5 T was 59·1 mol% and those of the four pinkish strains ranged from 60·5 to 61·8 mol%. Based on the results of phenotypic, genotypic, chemotaxonomic and phylogenetic investigation, two novel species, Loktanella agnita sp. nov. and Loktanella rosea sp. nov., are proposed. The type strains are R10SW5 T (=KMM 3788 T =CIP 107883 T ) and Fg36 T (=KMM 6003 T =CIP 107851 T =LMG 22534 T ), respectively.
Wing wettability of Odonata species as a function of quantity of epicuticular waxes
Publisher: Elsevier BV
Date: 11-2014
Bioelectromagnetics research within an Australian context: The Australian centre for electromagnetic bioeffects research (ACEBR)
Publisher: MDPI AG
Date: 29-09-2016
Translocation and fate of nanospheres in pheochromocytoma cells following exposure to synchrotron-sourced terahertz radiation
Publisher: International Union of Crystallography (IUCr)
Date: 20-06-2023
DOI: 10.1107/S1600577523004228
Abstract: The routes by which foreign objects enter cells is well studied however, their fate following uptake has not been explored extensively. Following exposure to synchrotron-sourced (SS) terahertz (THz) radiation, reversible membrane permeability has been demonstrated in eukaryotic cells by the uptake of nanospheres nonetheless, cellular localization of the nanospheres remained unclear. This study utilized silica core-shell gold nanospheres (AuSi NS) of diameter 50 ± 5 nm to investigate the fate of nanospheres inside pheochromocytoma (PC 12) cells following SS THz exposure. Fluorescence microscopy was used to confirm nanosphere internalization following 10 min of SS THz exposure in the range 0.5–20 THz. Transmission electron microscopy followed by scanning transmission electron microscopy energy-dispersive spectroscopic (STEM-EDS) analysis was used to confirm the presence of AuSi NS in the cytoplasm or membrane, as single NS or in clusters (22% and 52%, respectively), with the remainder (26%) sequestered in vacuoles. Cellular uptake of NS in response to SS THz radiation could have suitable applications in a vast number of biomedical applications, regenerative medicine, vaccines, cancer therapy, gene and drug delivery.
Correction for López-Pérez et al., Genome Sequence of “Thalassospira australica” NP3b2 T Isolated from St. Kilda Beach, Tasman Sea
Publisher: American Society for Microbiology
Date: 26-02-2015
Bacterial Extracellular Polysaccharides Involved in Biofilm Formation
Publisher: MDPI AG
Date: 13-07-2009
Metallic Superhydrophobic Surfaces
Publisher: Elsevier
Date: 2015
Mechanical inactivation of Staphylococcus aureus and Pseudomonas aeruginosa by titanium substrata with hierarchical surface structures
Publisher: Elsevier BV
Date: 03-2019
Advanced bioactive and biodegradable ceramic biomaterials
Publisher: Elsevier
Date: 2014
Biomaterial strategies to combat implant infections: new perspectives to old challenges
Publisher: Informa UK Limited
Date: 17-04-2023
Tunable morphological changes of asymmetric titanium nanosheets with bactericidal properties
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JCIS.2019.10.067
Abstract: Titanium and titanium alloys are often the most popular choice of material for the manufacture of medical implants however, they remain susceptible to the risk of device-related infection caused by the presence of pathogenic bacteria. Hydrothermal etching of titanium surfaces, to produce random nanosheet topologies, has shown remarkable ability to inactivate pathogenic bacteria via a physical mechanism. We expect that systematic tuning of the nanosheet morphology by controlling fabrication parameters, such as etching time, will allow for optimisation of the surface pattern for superior antibacterial efficacy. Using time-dependent hydrothermal processing of bulk titanium, we fabricated bactericidal nanosheets with variable nanoedge morphologies according to a function of etching time. A systematic study was performed to compare the bactericidal efficiency of nanostructured titanium surfaces produced at 0.5, 1, 2, 3, 4, 5, 6, 24 and 60 h of hydrothermal etching. Titanium surfaces hydrothermally treated for a period of 6 h were found to achieve maximal antibacterial efficiency of 99 ± 3% against Gram-negative Pseudomonas aeruginosa and 90 ± 9% against Gram-positive Staphylococcus aureus bacteria, two common human pathogens. These surfaces exhibited nanosheets with sharp edges of approximately 10 nm. The nanotopographies presented in this work exhibit the most efficient mechano-bactericidal activity against both Gram-negative and Gram-positive bacteria of any nanostructured titanium topography reported thus far.
Marinomonas pontica sp. nov., isolated from the Black Sea
Publisher: Microbiology Society
Date: 2005
Abstract: A Gram-negative, polarly flagellated bacterium was isolated from a sea-water s le collected from the Karadag Natural Reserve of the Eastern Crimea and characterized to clarify its taxonomic position. 16S rRNA gene sequence-based phylogenetic analysis of this novel organism revealed Marinomonas vaga, Marinomonas communis, Marinomonas mediterranea, Marinomonas primoryensis and 'Marinomonas protea' as its closest relatives (similarity 95-97 %). The G+C content of the DNA was 46.5 mol%. The organism grew between 4 and 33 degrees C, tolerated 10 % NaCl, was slightly alkaliphilic and was not able to degrade starch, gelatin, agar or Tween 80. Phosphatidylethanolamine (53.4 %) and phosphatidylglycerol (46.6 %) were the predominant phospholipids. The major fatty acids were 16 : 0 (15.5 %), 16 : 1omega7 (26.7 %) and 18 : 1omega7 (47.1 %). The phylogenetic, genetic and physiological properties of the organism placed it within a novel species, proposed as Marinomonas pontica sp. nov., the type strain of which is 46-16T (=LMG 22531T=KMM 3492T=UCM 11075T).
Localization of nanospheres in pheochromocytoma-like cells following exposure to high-frequency electromagnetic fields at 18 GHz
Publisher: The Royal Society
Date: 06-2022
DOI: 10.1098/RSOS.220520
Abstract: Exposure to high-frequency (HF) electromagnetic fields (EMFs) at 18 GHz was previously found to induce reversible cell permeabilization in eukaryotic cells however, the fate of internalized foreign objects inside the cell remains unclear. Here, silica core–shell gold nanospheres (Au NS) of 20 ± 5 nm diameter were used to study the localization of Au NS in pheochromocytoma (PC 12) cells after exposure to HF EMFs at 18 GHz. Internalization of Au NS was confirmed using fluorescence microscopy and transmission electron microscopy. Analysis based on corresponding scanning transmission electron microscopy energy-dispersive spectroscopy revealed the presence of the Au NS free within the PC 12 cell membrane, cytoplasm, enclosed within intracellular vesicles and sequestered in vacuoles. The results obtained in this work highlight that exposure to HF EMFs could be used as an efficient technique with potential for effective delivery of drugs, genetic material, and nanomaterials into cells for the purpose of cellular manipulation or therapy.
Structure and Optical Anisotropy of Spider Scales and Silk: The Use of Chromaticity and Azimuth Colors to Optically Characterize Complex Biological Structures
Publisher: MDPI AG
Date: 20-06-2023
DOI: 10.3390/NANO13121894
Abstract: Herein, we give an overview of several less explored structural and optical characterization techniques useful for biomaterials. New insights into the structure of natural fibers such as spider silk can be gained with minimal s le preparation. Electromagnetic radiation (EMR) over a broad range of wavelengths (from X-ray to THz) provides information of the structure of the material at correspondingly different length scales (nm-to-mm). When the s le features, such as the alignment of certain fibers, cannot be characterized optically, polarization analysis of the optical images can provide further information on feature alignment. The 3D complexity of biological s les necessitates that there be feature measurements and characterization over a large range of length scales. We discuss the issue of characterizing complex shapes by analysis of the link between the color and structure of spider scales and silk. For ex le, it is shown that the green-blue color of a spider scale is dominated by the chitin slab’s Fabry–Pérot-type reflectivity rather than the surface nanostructure. The use of a chromaticity plot simplifies complex spectra and enables quantification of the apparent colors. All the experimental data presented herein are used to support the discussion on the structure–color link in the characterization of materials.
Accelerated stem cell attachment to ultrafine grained titanium
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.ACTBIO.2010.09.033
Abstract: Commercial purity titanium with an average grain size in the low sub-micron range was produced by equal channel angular pressing (ECAP). Attachment of human bone marrow-derived mesenchymal stem cells (hMSCs) to the surface of conventional coarse grained and ECAP-modified titanium was studied. It was demonstrated that the attachment and spreading of hMSCs in the initial stages (up to 24h) of culture was enhanced by grain refinement. Surface characterization by a range of techniques showed that the main factor responsible for the observed acceleration of hMSC attachment and spreading on titanium due to grain refinement in the bulk is the attendant changes in surface topography on the nanoscale. These results indicate that, in addition to its superior mechanical properties, ECAP-modified titanium possesses improved biocompatibility, which makes it to a potent candidate for applications in medical implants.
Draft genome sequences of Marinobacter similis A3d10Tand Marinobacter salarius R9SW1T
Publisher: American Society for Microbiology
Date: 26-06-2014
Abstract: Here, we present the draft genomes of Marinobacter similis A3d10 T , a potential plastic biodegrader, and Marinobacter salarius R9SW1 T , isolated from radioactive waters. This genomic information will contribute information on the genetic basis of the metabolic pathways for the degradation of both plastic and radionuclides.
Three-Dimensional Hierarchical Wrinkles on Polymer Films: From Chaotic to Ordered Antimicrobial Topographies
Publisher: Elsevier BV
Date: 05-2020
Nano-structured antimicrobial surfaces: From nature to synthetic analogues
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.JCIS.2017.07.021
Abstract: The scientific and industrial interest in antimicrobial surfaces has significantly increased in recent times. This interest is largely in response to the persistent microbial contamination of industrial and, importantly, medical implant surfaces. Bacterial contamination of implant surfaces often leads to infection at the implant-tissue interface, and with the prevalence of increasing levels of antimicrobial resistance, the treatment of these infections is becoming far more challenging. Recently, many naturally occurring, high-aspect-ratio surface topographies have been discovered that exhibit high levels of biocidal efficacy. These include epicuticular lipid nano-architectures that are formed on the surfaces of insect wings, such as cicadae and dragonflies. The antimicrobial activity of such surfaces has been found to be a consequence of the physical interactions between the nanoscale topography of the substrate and the attaching pathogenic cells, meaning that the activity is independent of biochemical surface functionality. Importantly, these desirable surface properties can be translated to synthetic biomimetic surfaces, which, when mimicked, lead to a substantial increase in the antimicrobial properties of such surfaces. This paper reviews the recent advances in understanding the basis of these mechanical antimicrobial mechanisms, and discusses the progress being made towards the fabrication of optimised, biocompatible, synthetic analogues.
Chemically non-perturbing SERS detection of a catalytic reaction with black silicon
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8NR02123F
Abstract: All-dielectric resonant nanostructures made of high-index dielectrics have recently emerged as a promising surface-enhanced Raman scattering platform which can complement or replace the metal-based counterparts in routine sensing measurements.
Highly efficient tabletop x-ray laser at λ=41.8 nm in Pd-like xenon pumped by optical-field ionization in a cluster jet
Publisher: American Physical Society (APS)
Date: 19-10-2011
Presence of Ecophysiologically Diverse Populations within Cobetia marina Strains Isolated from Marine Invertebrate, Algae and the Environments
Publisher: Japanese Society of Microbial Ecology
Date: 2005
DOI: 10.1264/JSME2.20.200
Bio-inspired sustainable and durable superhydrophobic materials: from nature to market
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA05185F
Abstract: This review attempts to highlight the recent progress in the design, synthesis and fabrication of fluorine-free superhydrophobic surfaces.
The structure of the O-polysaccharide of the Pseudoalteromonas rubra ATCC 29570Tlipopolysaccharide containing a keto sugar
Publisher: Elsevier BV
Date: 10-2005
DOI: 10.1016/J.CARRES.2005.07.007
Abstract: The structure of the phenol-soluble polysaccharide from Pseudoalteromonas rubra type strain ATCC 29570T has been elucidated using 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, gNOESY, ROESY, 1H,13C gHMQC and gHMBC experiments. It is concluded that the trisaccharide repeating unit of the polysaccharide has the following structure: [carbohydrate structure: see text] where Sug is 2-acetamido-2,6-dideoxy-D-xylo-hexos-4-ulose, Am is acetimidoyl and Acyl is a malic acid residue, which is O-acetylated in approximately 70% of the units.
Impact of ketone and amino on the inner shell of guanine
Publisher: International Union of Crystallography (IUCr)
Date: 19-05-2009
Transition probabilities for 5s-5p, 5p-5d, 4f-5d, and 5d-5f transitions in Ag-like ions with Z=50-86
Publisher: Elsevier BV
Date: 2011
Pillars of Life: Is There a Relationship between Lifestyle Factors and the Surface Characteristics of Dragonfly Wings?
Publisher: American Chemical Society (ACS)
Date: 05-06-2018
Surface hydrophobicity modulates the operation of protein molecular motors
Publisher: IEEE
Date: 2006
Genomes of Alteromonas australica,a world apart
Publisher: Springer Science and Business Media LLC
Date: 18-06-2014
Vibrio fischeri and Escherichia coli adhesion tendencies towards photolithographically modified nanosmooth poly (tert-butyl methacrylate) polymer surfaces
Publisher: Informa UK Limited
Date: 09-2008
DOI: 10.2147/NSA.S3571
Statistically quantified measurement of an Alzheimer's marker by surface-enhanced Raman scattering
Publisher: Wiley
Date: 13-08-2015
Abstract: Fibrillar forms of the Amyloid-β (Aβ) protein have been implicated in the early stages of Alzheimer's disease (AD), however there are no standardised assays for soluble Aβ oligomer biomarkers that provide the best indication of the disease progression [1,2]. As a step towards a fast and label-free method for testing different AD biomarkers, we have combined laser nano-textured substrates with a SERS mapping technique and validated it using soluble Aβ-40 oligomers [3-5]. The nano-textured SERS substrates provide fast ( min), label-free spectra associated with soluble Aβ-40 oligomers down to a concentration of 10 nM. Statistical analysis of the spectral intensities mapped over the substrate surface shows a quantitative correlation with the oligomer concentration. Schematics of experiments: SERS mapping of Aβ-40 (left figure: measured SERS intensity overlayed with an SEM image of ripples) was carried out on the laser nano-textured (ripple) surface of sapphire and statistical analysis of the SERS intensity was carried out for qualitative (a high SERS intensity at low probability) and quantitative (a moderate SERS intenisty at the highest probability) measures. Quantitative statistical analysis of SERS mapping data can be performed off line for cross correlations with other known SERS signatures.
Bacterial extracellular polysaccharides
Publisher: Springer Netherlands
Date: 2011
DOI: 10.1007/978-94-007-0940-9_13
Abstract: Extracellular polysaccharides are as structurally and functionally erse as the bacteria that synthesise them. They can be present in many forms, including cell-bound capsular polysaccharides, unbound "slime", and as O-antigen component of lipopolysaccharide, with an equally wide range of biological functions. These include resistance to desiccation, protection against nonspecific and specific host immunity, and adherence. Unsurprisingly then, much effort has been made to catalogue the enormous structural complexity of the extracellular polysaccharides made possible by the wide assortment of available monosaccharide combinations, non-carbohydrate residues, and linkage types, and to elucidate their biosynthesis and export. In addition, the work is driven by the commercial potential of these microbial substances in food, pharmaceutics and biomedical industries. Most recently, bacteria-mediated environmental restoration and bioleaching have been attracting much attention owing to their potential to remediate environmental effluents produced by the mining and metallurgy industries. In spite of technological advances in chemistry, molecular biology and imaging techniques that allowed for considerable expansion of knowledge pertaining to the bacterial surface polysaccharides, current understanding of the mechanisms of synthesis and regulation of extracellular polysaccharides is yet to fully explain their structural intricacy and functional variability.
32.8-nm X-ray laser produced in a krypton cluster jet
Publisher: IOP Publishing
Date: 31-12-2013
Introduction to biomaterials and implantable device design
Publisher: Elsevier
Date: 2014
Three-Dimensional Organization of Self-Encapsulating Gluconobacter oxydans Bacterial Cells
Publisher: American Chemical Society (ACS)
Date: 20-11-2017
Applications of Nanotextured Surfaces
Publisher: Elsevier
Date: 2015
Evaluation of Current Molecular Approaches for Genotyping ofCampylobacter jejuniStrains
Publisher: Mary Ann Liebert Inc
Date: 05-2012
Abstract: C ylobacter jejuni has been recognized as the most common bacterial cause of gastroenteritis worldwide, in both developed and developing countries, since the late 1970s. A number of genotyping schemes have been developed to identify the sources and route of transmission of these foodborne pathogens so that proper control measures can be developed. In this review, we provide current genotypic schemes developed for C ylobacter spp. (particularly C. jejuni) over the last decades, along with an evaluation of the strength and weakness of these techniques and their applications.
Influence of nanoscale topology on bactericidal efficiency of black silicon surfaces
Publisher: IOP Publishing
Date: 23-05-2017
Abstract: The nanostructuring of materials to create bactericidal and antibiofouling surfaces presents an exciting alternative to common methods of preventing bacterial adhesion. The fabrication of synthetic bactericidal surfaces has been inspired by the anti-wetting and anti-biofouling properties of insect wings, and other topologies found in nature. Black silicon is one such synthetic surfaces which has established bactericidal properties. In this study we show that time-dependent plasma etching of silicon wafers using 15, 30, and 45 min etching intervals, is able to produce different surface geometries with linearly increasing heights of approximately 280, 430, and 610 nm, respectively. After incubation on these surfaces with Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa bacterial cells it was established that smaller, more densely packed pillars exhibited the greatest bactericidal activity with 85% and 89% inactivation of bacterial cells, respectively. The decrease in the pillar heights, pillar cap diameter and inter-pillar spacing corresponded to a subsequent decrease in the number of attached cells for both bacterial species.
Apoptosis of Multi‐Drug Resistant Candida Species on Microstructured Titanium Surfaces
Publisher: Wiley
Date: 17-08-2023
Abstract: The proportion of hospital‐acquired medical device infections caused by pathogenic, multi‐drug resistant Candida species occurs in up to 10% of implantations. In this study, a unique antifungal micro‐pillared titanium surface pattern is developed, which demonstrates both fungicidal and fungistatic activity, persistently deterring biofilm formation by Candida albicans and multi‐drug resistant Candida auris fungi for up to 7 days. The Ti micropillars of 3.5 µm height are fabricated using maskless inductively coupled plasma reactive ion etching. The micro‐textured surface consistently kills ≈50% of Candida spp. irreversibly attached cells and prevent the proliferation of the remaining cells by inducing programmed cell death. Proteomic analysis reveals that Candida cells undergo extensive metabolic stress, preventing the transformation from yeast to the filamentous/hyphal cell phenotype that is essential for establishing a typical in vitro biofilm. The mechanical stress imparted following interaction with the micropillars injures attaching cells and induces apoptosis whereby the Candida cells are unable to be revived in a non‐stress environment. These findings shed new insight toward the design of durable antifungal surfaces that prevent biofilm formation by pathogenic, multi‐drug resistant yeasts.
Antibacterial titanium nano-patterned arrays inspired by dragonfly wings
Publisher: Springer Science and Business Media LLC
Date: 18-11-2015
DOI: 10.1038/SREP16817
Abstract: Titanium and its alloys remain the most popular choice as a medical implant material because of its desirable properties. The successful osseointegration of titanium implants is, however, adversely affected by the presence of bacterial biofilms that can form on the surface and hence methods for preventing the formation of surface biofilms have been the subject of intensive research over the past few years. In this study, we report the response of bacteria and primary human fibroblasts to the antibacterial nanoarrays fabricated on titanium surfaces using a simple hydrothermal etching process. These fabricated titanium surfaces were shown to possess selective bactericidal activity, eliminating almost 50% of Pseudomonas aeruginosa cells and about 20% of the Staphylococcus aureus cells coming into contact with the surface. These nano-patterned surfaces were also shown to enhance the aligned attachment behavior and proliferation of primary human fibroblasts over 10 days of growth. These antibacterial surfaces, which are capable of exhibiting differential responses to bacterial and eukaryotic cells, represent surfaces that have excellent prospects for biomedical applications.
Updating the taxonomic toolbox: classification of Alteromonas spp. using multilocus phylogenetic analysis and MALDI-TOF mass spectrometry
Publisher: Springer Science and Business Media LLC
Date: 11-09-2012
DOI: 10.1007/S10482-012-9807-Y
Abstract: Bacteria of the genus Alteromonas are Gram-negative, strictly aerobic, motile, heterotrophic marine bacteria known for their versatile metabolic activities. Identification and classification of novel species belonging to the genus Alteromonas generally involves DNA-DNA hybridization (DDH) as distinct species often fail to be resolved at the 97 % threshold value of the 16S rRNA gene sequence similarity. In this study, the applicability of Multilocus Phylogenetic Analysis (MLPA) and Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) for the differentiation of Alteromonas species has been evaluated. Phylogenetic analysis incorporating five house-keeping genes (dnaK, sucC, rpoB, gyrB, and rpoD) revealed a threshold value of 98.9 % that could be considered as the species cut-off value for the delineation of Alteromonas spp. MALDI-TOF MS data analysis reconfirmed the Alteromonas species clustering. MLPA and MALDI-TOF MS both generated data that were comparable to that of the 16S rRNA gene sequence analysis and may be considered as useful complementary techniques for the description of new Alteromonas species.
Bactericidal activity of self-assembled palmitic and stearic fatty acid crystals on highly ordered pyrolytic graphite
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.ACTBIO.2017.07.004
Abstract: The wings of insects such as cicadas and dragonflies have been found to possess nanostructure arrays that are assembled from fatty acids. These arrays can physically interact with the bacterial cell membranes, leading to the death of the cell. Such mechanobactericidal surfaces are of significant interest, as they can kill bacteria without the need for antibacterial chemicals. Here, we report on the bactericidal effect of two of the main lipid components of the insect wing epicuticle, palmitic (C16) and stearic (C18) fatty acids. Films of these fatty acids were re-crystallised on the surface of highly ordered pyrolytic graphite. It appeared that the presence of two additional CH Nanostructured cicada and dragonfly wing surfaces have been discovered to be able physically kill bacterial cells. Here, we report on the successful fabrication of bactericidal three-dimensional structures of two main lipid components of the epicuticle of insect wings, palmitic (C16) and stearic (C18) acids. After crystallisation onto highly ordered pyrolytic graphite, both the palmitic and stearic acid films displayed bactericidal activity against both Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus cells. The simplicity of the production of these microcrystallite interfaces suggests that a fabrication technique, based on solution deposition, could be an effective technique for the application of bactericidal nanocoatings.
Bacterial interactions with optical fibre surfaces
Publisher: IEEE
Date: 02-2010
Quasicontinuous x-ray laser with λ=10.8 nm in Pd-like tungsten using a nanostructured target
Publisher: American Physical Society (APS)
Date: 15-10-2010
A superpowerful source of far-ultraviolet monochromatic radiation
Publisher: Pleiades Publishing Ltd
Date: 05-2005
DOI: 10.1134/1.1947309
Study of melanin localization in the mature male Calopteryx haemorrhoidalis damselfly wings
Publisher: International Union of Crystallography (IUCr)
Date: 25-04-2018
DOI: 10.1107/S1600577518004460
Abstract: Damselflies Calopteryx haemorrhoidalis exhibiting black wings are found in the western Mediterranean, Algeria, France, Italy, Spain and Monaco. Wing pigmentation is caused by the presence of melanin, which is involved in physiological processes including defence reactions, wound healing and sclerotization of the insect. Despite the important physiological roles of melanin, the presence and colour variation among males and females of the C. haemorrhoidalis species and the localization of the pigment within the wing membrane remain poorly understood. In this study, infrared (IR) microspectroscopy, coupled with the highly collimated synchrotron IR beam, was employed in order to identify the distribution of the pigments in the wings at a high spatial resolution. It was found that the melanin is localized in the procuticle of the C. haemorrhoidalis damselfly wings, distributed homogeneously within this layer, and not associated with the lipids of the epicuticle.
Nature inspired structured surfaces for biomedical applications
Publisher: Bentham Science Publishers Ltd.
Date: 08-2011
DOI: 10.2174/092986711796504673
Abstract: Nature has created an array of superhydrophobic surfaces that possess water-repellent, self-cleaning and anti-icing properties. These surfaces have a number of potential applications in the biomedical industry, as they have the potential to control protein adsorption and cell adhesion. Natural superhydrophobic surfaces are typically composed of materials with a low intrinsic surface free-energy (e.g the cuticular waxes of lotus leaves and insect wings) with a hierarchical structural configuration. This hierarchical surface topography acts to decrease the contact area of water droplets in contact with the surface, thereby increasing the extent of the air/water interface, resulting in water contact angles greater than 150º. In order to employ these surfaces in biotechnological applications, fabrication techniques must be developed so that these multi-scale surface roughness characteristics can be reproduced. Additionally, these fabrication techniques must also be able to be applied to the material required for the intended application. An overview of some of the superhydrophobic surfaces that exist in nature is presented, together with an explanation of the theories of their wettability. Also included is a description of some of the biomedical applications of superhydrophobic surfaces and fabrication techniques that can be used to mimic superhydrophobic surfaces found in nature.
The susceptibility of Staphylococcus aureus CIP 65.8 and Pseudomonas aeruginosa ATCC 9721 cells to the bactericidal action of nanostructured Calopteryx haemorrhoidalis damselfly wing surfaces
Publisher: Springer Science and Business Media LLC
Date: 03-2017
DOI: 10.1007/S00253-017-8205-9
Abstract: Nanostructured insect wing surfaces have been reported to possess the ability to resist bacterial colonization through the mechanical rupture of bacterial cells coming into contact with the surface. In this work, the susceptibility of physiologically young, mature and old Staphylococcus aureus CIP 65.8 and Pseudomonas aeruginosa ATCC 9721 bacterial cells, to the action of the bactericidal nano-pattern of damselfly Calopteryx haemorrhoidalis wing surfaces, was investigated. The results were obtained using several surface characterization techniques including optical profilometry, scanning electron microscopy, synchrotron-sourced Fourier transform infrared microspectroscopy, water contact angle measurements and antibacterial assays. The data indicated that the attachment propensity of physiologically young S. aureus CIP 65.8
Mechano-Bactericidal Titanium Surfaces for Bone Tissue Engineering
Publisher: American Chemical Society (ACS)
Date: 15-10-2020
Natural Insect and Plant Micro-/Nanostructsured Surfaces: An Excellent Selection of Valuable Templates with Superhydrophobic and Self-Cleaning Properties
Publisher: MDPI AG
Date: 02-09-2014
Physico-mechanical characterisation of cells using atomic force microscopy - Current research and methodologies
Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.MIMET.2011.05.021
Abstract: Atomic force microscopy (AFM) is a technique that has long been employed in materials science, but is now increasingly being used in the biological sciences. AFM provides excellent topographical information on prokaryotic and eukaryotic cell surfaces, and the extracellular material produced by the cells. It helps to generate important data on the mechanical properties of cells, such as hardness and elasticity. AFM can also be used to measure the strength of adhesion, attraction, and repulsion forces between cells and surfaces or even between in idual molecules. Additionally, by combining AFM with other complementary techniques such as fluorescence microscopy or Raman spectroscopy, the chemistry of given surface structures can be identified. This review aims to provide an update on the AFM techniques currently used in cell biology studies, along with a description of the range of recently developed research methodologies in which AFM plays a key role.
Biophysical model of bacterial cell interactions with nanopatterned cicada wing surfaces
Publisher: Elsevier BV
Date: 02-2013
Development of a microwave treatment technique for bacterial decontamination of raw meat
Publisher: Walter de Gruyter GmbH
Date: 08-05-2008
Abstract: The present study developed and verified a 'cold' microwave (MW) treatment that could lead to the inactivation of two common pathogenic species of bacteria, Escherichia coli and Staphylococcus aureus, in raw meats. A number of experimental conditions were designed and tested to maximise MW exposure without overheating the s les. The non-thermal effect was maximised by multiple exposure to attain efficient MW threshold intensities. It was shown that at sub-lethal temperatures repeated exposure using high frequency MW radiation was significantly more effective in decontaminating bacteria in raw meats compared to a single exposure. It was concluded that non thermal inactivation of pathogenic bacteria in raw meats could be achieved at defined conditions using high frequency MW radiation.
Multi-directional electrodeposited gold nanospikes for antibacterial surface applications
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8NA00124C
Abstract: Bactericidal interactions of Pseudomonas aeruginosa cells with multi-directional gold nanospikes.
Complete Structural Elucidation of a Novel Lipooligosaccharide from the Outer Membrane of the Marine Bacterium Shewanella pacifica
Publisher: Wiley
Date: 25-05-2005
Lethal Interactions of Atomically Precise Gold Nanoclusters and Pseudomonas aeruginosa and Staphylococcus aureus Bacterial Cells
Publisher: American Chemical Society (ACS)
Date: 27-06-2022
Abstract: Ultrasmall metal nanoclusters (NCs) are employed in an array of diagnostic and therapeutic applications due to their tunable photoluminescence, high biocompatibility, polyvalent effect, ease of modification, and photothermal stability. However, gold nanoclusters' (AuNCs') intrinsically antimicrobial properties remain poorly explored and are not well understood. Here, we share an insight into the antimicrobial action of atomically precise AuNCs based on their ability to passively translocate across the bacterial membrane. Functionalized by a hydrophilic modified-bidentate sulfobetaine zwitterionic molecule (AuNC-ZwBuEt) or a more hydrophobic monodentate-thiolate, mercaptohexanoic acid (AuNC-MHA) molecule, 2 nm AuNCs were lethal to both Gram-negative
Antibacterial surfaces: The quest for a new generation of biomaterials
Publisher: Elsevier BV
Date: 05-2013
DOI: 10.1016/J.TIBTECH.2013.01.017
Abstract: In this review we attempt to clarify the notion of what is meant by the term antibacterial surfaces and categorise the approaches that are commonly used in the design of antibacterial surfaces. Application of surface coatings and the modification of the surface chemistry of substrata are generally considered to be a chemical approach to surface modification (as are surface polymerisation, functionalisation, and derivatisation), whereas, modification of the surface architecture of a substrate can be considered a physical approach. Here, the antifouling and bactericidal effects of antibacterial surfaces are briefly discussed. Finally, several recent efforts to design a new generation of antibacterial surfaces, which are based on mimicking the surface nanotopography of natural surfaces, are considered.
Bacterial attachment on sub-nanometrically smooth titanium substrata
Publisher: Informa UK Limited
Date: 17-01-2013
DOI: 10.1080/08927014.2012.757697
Abstract: Despite the volume of work that has been conducted on the topic, the role of surface topography in mediating bacterial cell adhesion is not well understood. The primary reason for this lack of understanding is the relatively limited extent of topographical characterisation employed in many studies. In the present study, the topographies of three sub-nanometrically smooth titanium (Ti) surfaces were comprehensively characterised, using nine in idual parameters that together describe the height, shape and distribution of their surface features. This topographical analysis was then correlated with the adhesion behaviour of the pathogenic bacteria Staphylococcus aureus and Pseudomonas aeruginosa, in an effort to understand the role played by each aspect of surface architecture in influencing bacterial attachment. While P. aeruginosa was largely unable to adhere to any of the three sub-nanometrically smooth Ti surfaces, the extent of S. aureus cell attachment was found to be greater on surfaces with higher average, RMS and maximum roughness and higher surface areas. The cells also attached in greater numbers to surfaces that had shorter autocorrelation lengths and skewness values that approached zero, indicating a preference for less ordered surfaces with peak heights and valley depths evenly distributed around the mean plane. Across the sub-nanometrically smooth range of surfaces tested, it was shown that S. aureus more easily attached to surfaces with larger features that were evenly distributed between peaks and valleys, with higher levels of randomness. This study demonstrated that the traditionally employed litudinal roughness parameters are not the only determinants of bacterial adhesion, and that spatial parameters can also be used to predict the extent of attachment.
Influence of nanoscale topology on the bactericidal efficiency of black silicon surfaces (vol 28, 245301, 2017)
Publisher: IOP Publishing
Date: 20-10-2017
Structure of the repeat unit of the Alteromonas addita type strain KMM 3600T O-specific polysaccharide
Publisher: Springer Science and Business Media LLC
Date: 09-2008
Comment on bactericidal Effects of Natural Nanotopography of Dragonfly Wing on Escherichia coli
Publisher: American Chemical Society (ACS)
Date: 24-08-2017
Recent Advances in Macro ATR-FTIR Microspectroscopic Technique for High Resolution Surface Characterisation at Australian Synchrotron IR Beamline
Publisher: OSA
Date: 2018
Nanofabrication of mechano-bactericidal surfaces
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR05881K
Abstract: The search for alternatives to standard methods of preventing bacterial adhesion and biofilm formation on biotic and abiotic surfaces alike has led to the use of biomimetics to reinvent, through nanofabrication methods, surfaces whereby the nanostructured topography is directly responsible for bacterial inactivation through physico-mechanical means.
Pseudomonas brassicacearum subsp. neoaurantiaca subsp. nov., orange-pigmented bacteria isolated from soil and the rhizosphere of agricultural plants
Publisher: Microbiology Society
Date: 21-07-2009
Abstract: A large group of 38 strains of saprophytic bacteria was isolated from soil and the rhizosphere of agricultural plants. The novel organisms were Gram-negative, aerobic, rod-shaped bacteria that produced a green fluorescent pigment, a red-orange diffusible pigment and a complex mixture of phloroglucinol derivates with antimicrobial activity. The latter have not been found in other bacteria, but are peculiar to ferns. The bacteria were vigorous denitrifiers that synthesized levan from sucrose and liquefied gelatin, but were found not to degrade aesculin, starch, agar, Tween 80 or DNA. Bacterial growth was found to occur at 4 degrees C but not at 40 degrees C. The predominant cellular fatty acids were 16 : 0, 16 : 1(n-7), 18 : 1(n-7) and 17 : 0 cyclo. The G+C content of the novel bacteria was 61.0-62.9 mol%. 16S rRNA gene sequence analysis indicated that the representative strain CIP 109457(T) had a clear affiliation with Pseudomonas sensu stricto groups, with the nearest relatives being Pseudomonas brassicacearum, P. thivervalensis, P. corrugata, P. mediterranea and P. kilonensis. DNA-DNA hybridization experiments showed that the group of isolated strains exhibited high levels of genetic relatedness (81-100 %), confirming that they are representatives of the same species. At the same time, they bound at low levels (4-46 %) with DNA of the type strains of their nearest relatives with the exception of P. brassicacearum DNA binding of 90 % with the DNA of P. brassicacearum CIP 107059(T) suggested that the bacteria studied belong to this species. Analysis of taxonomic data indicated that the group of novel bacteria maintain a distinct phenotypic profile, allowing the description of novel subspecies within P. brassicacearum, for which the following names are proposed: Pseudomonas brassicacearum subsp. brassicacearum subsp. nov. (type strain DBK11(T) =CFBP 11706(T) =CIP 107059(T) =DSM 13227(T) =JCM 11938(T)) and Pseudomonas brassicacearum subsp. neoaurantiaca subsp. nov., with the type strain CIP 109457(T) (=ATCC 49054(T) =IMV 387(T) =VKM B-1524(T)).
Bioinert ceramic biomaterials: advanced applications
Publisher: Elsevier
Date: 2014
Self-organised nanoarchitecture of titanium surfaces influences the attachment of Staphylococcus aureus and Pseudomonas aeruginosa bacteria
Publisher: Springer Science and Business Media LLC
Date: 17-04-2015
DOI: 10.1007/S00253-015-6572-7
Abstract: The surface nanotopography and architecture of medical implant devices are important factors that can control the extent of bacterial attachment. The ability to prevent bacterial attachment substantially reduces the possibility of a patient receiving an implant contracting an implant-borne infection. We now demonstrated that two bacterial strains, Staphylococcus aureus and Pseudomonas aeruginosa, exhibited different attachment affinities towards two types of molecularly smooth titanium surfaces each possessing a different nanoarchitecture. It was found that the attachment of S. aureus cells was not restricted on surfaces that had an average roughness (S a) less than 0.5 nm. In contrast, P. aeruginosa cells were found to be unable to colonise surfaces possessing an average roughness below 1 nm, unless sharp nanoprotrusions of approximately 20 nm in size and spaced 35.0 nm apart were present. It is postulated that the enhanced attachment of P. aeruginosa onto the surfaces possessing these nanoprotrusions was facilitated by the ability of the cell membrane to stretch over the tips of the nanoprotrusions as confirmed through computer simulation, together with a concomitant increase in the level of extracellular polymeric substance (EPS) being produced by the bacterial cells.
The Family Pseudoalteromonadaceae
Publisher: Springer Berlin Heidelberg
Date: 2014
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