ORCID Profile
0000-0002-8671-181X
Current Organisations
University of South Australia
,
Flinders 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)
Nanomanufacturing | Physical Chemistry of Materials | Functional Materials | Macromolecular and materials chemistry not elsewhere classified | Chemical engineering | Macromolecular and Materials Chemistry | Materials Engineering | Electrochemical energy storage and conversion
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in Engineering | Expanding Knowledge in Technology | Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in the Physical Sciences |
Related Links
Publications
Back cover
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CC90010A
Secrets of plasma-deposited polyoxazoline functionality lie in the plasma phase
Publisher: American Chemical Society (ACS)
Date: 29-09-2017
Smart polymer-clay composite nanomaterials
Publisher: IEEE
Date: 02-2014
Nanoscale steric hindrance guides size-selective adsorption of gold nanoparticles into titanium nanowells
Publisher: Elsevier BV
Date: 04-2023
A platform for selective immuno-capture of cancer cells from urine
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.BIOS.2017.02.011
Abstract: Urothelial cancers are amongst the 10 most common types of cancer and represent a major health problem worldwide. Current urinary diagnostic tests for urothelial cancer are expensive and have limited sensitivity and specificity. In this work, proofs of concept for a selective cancer cell capture platform are presented with the aim to achieve the first generation of specific urinary tests for the detection of cancer cells in urine specimen. The unique reactivity of plasma deposited polyoxazoline was used to covalently bind cancer specific antibodies in microchannels. Cancer cells dispersed in patient urine were successfully captured with up to 99% selectivity and 100% sensitivity over a wide range of cell concentrations. The streamlined two steps preparation process of the capture platform represents an important advance in medical diagnostics, with broader potential applications.
Plasma deposited polyoxazoline thin films for the biofunctionalization of electrochemical sensors
Publisher: Wiley
Date: 09-06-2021
Abstract: Electrochemical immunosensors are an emerging technology for the fast, sensitive, and reliable diagnosis of diseases from bodily fluids. These sensors work by detecting a change in current upon analyte binding to an immuno‐functionalized electrode. Current methods of electrode functionalization are lengthy processes involving self‐assembled monolayer formation and wet chemistry biofunctionalization. Herein, thin films deposited from the plasma phase of oxazoline precursors are investigated and optimized as an alternative approach for electrode functionalization. The plasma‐enabled method has the advantage of being substrate independent and allows the spontaneous binding of biomolecules in physiological buffer. Surface sensitive analysis techniques are employed to characterize the thickness, reactivity, and stability of the thin films before investigating their electrochemical properties on indium tin oxide and gold electrodes including the feasibility to reduce charge transfer resistance with gold nanoparticles. Last, these films are employed to develop an immunosensor for the detection of free epithelial cell adhesion molecule with a limit of detection of 8.7 ng mL −1 .
Nanoparticles Surface Chemistry Influence on Protein Corona Composition and Inflammatory Responses
Publisher: MDPI AG
Date: 18-02-2022
DOI: 10.3390/NANO12040682
Abstract: Nanoparticles are widely used for biomedical applications such as vaccine, drug delivery, diagnostics, and therapeutics. This study aims to reveal the influence of nanoparticle surface functionalization on protein corona formation from blood serum and plasma and the subsequent effects on the innate immune cellular responses. To achieve this goal, the surface chemistry of silica nanoparticles of 20 nm diameter was tailored via plasma polymerization with amine, carboxylic acid, oxazolines, and alkane functionalities. The results of this study show significant surface chemistry-induced differences in protein corona composition, which reflect in the subsequent inflammatory consequences. Nanoparticles rich with carboxylic acid surface functionalities increased the production of pro-inflammatory cytokines in response to higher level of complement proteins and decreased the number of lipoproteins found in their protein coronas. On another hand, amine rich coatings led to increased expressions of anti-inflammatory markers such as arginase. The findings demonstrate the potential to direct physiological responses to nanomaterials via tailoring their surface chemical composition.
Perspective on Plasma Polymers for Applied Biomaterials Nanoengineering and the Recent Rise of Oxazolines
Publisher: MDPI AG
Date: 08-01-2019
DOI: 10.3390/MA12010191
Abstract: Plasma polymers are unconventional organic thin films which only partially share the properties traditionally attributed to polymeric materials. For instance, they do not consist of repeating monomer units but rather present a highly crosslinked structure resembling the chemistry of the precursor used for deposition. Due to the complex nature of the deposition process, plasma polymers have historically been produced with little control over the chemistry of the plasma phase which is still poorly understood. Yet, plasma polymer research is thriving, in par with the commercialisation of innumerable products using this technology, in fields ranging from biomedical to green energy industries. Here, we briefly summarise the principles at the basis of plasma deposition and highlight recent progress made in understanding the unique chemistry and reactivity of these films. We then demonstrate how carefully designed plasma polymer films can serve the purpose of fundamental research and biomedical applications. We finish the review with a focus on a relatively new class of plasma polymers which are derived from oxazoline-based precursors. This type of coating has attracted significant attention recently due to its unique properties.
Creating Nano-engineered Biomaterials with Well-Defined Surface Descriptors
Publisher: American Chemical Society (ACS)
Date: 16-05-2018
Biomaterial Surface Hydrophobicity-Mediated Serum Protein Adsorption and Immune Responses
Publisher: American Chemical Society (ACS)
Date: 16-07-2019
Abstract: The nature of the protein corona forming on biomaterial surfaces can affect the performance of implanted devices. This study investigated the role of surface chemistry and wettability on human serum-derived protein corona formation on biomaterial surfaces and the subsequent effects on the cellular innate immune response. Plasma polymerization, a substrate-independent technique, was employed to create nanothin coatings with four specific chemical functionalities and a spectrum of surface charges and wettability. The amount and type of protein adsorbed was strongly influenced by surface chemistry and wettability but did not show any dependence on surface charge. An enhanced adsorption of the dysopsonin albumin was observed on hydrophilic carboxyl surfaces while high opsonin IgG2 adsorption was seen on hydrophobic hydrocarbon surfaces. This in turn led to a distinct immune response from macrophages hydrophilic surfaces drove greater expression of anti-inflammatory cytokines by macrophages, whilst surface hydrophobicity caused increased production of proinflammatory signaling molecules. These findings map out a unique relationship between surface chemistry, hydrophobicity, protein corona formation, and subsequent cellular innate immune responses the potential outcomes of these studies may be employed to tailor biomaterial surface modifications, to modulate serum protein adsorption and to achieve the desirable innate immune response to implanted biomaterials and devices.
Antibiofouling Properties of Plasma-Deposited Oxazoline-Based Thin Films
Publisher: American Chemical Society (ACS)
Date: 03-2016
Abstract: Infections caused by the bacterial colonization of medical devices are a substantial problem to patients and healthcare. Biopassive polyoxazoline coatings are attracting attention in the biomedical field as one of the potential solutions to this problem. Here, we present an original and swift way to produce plasma-deposited oxazoline-based films for antifouling applications. The films developed via the plasma deposition of 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline have tunable thickness and surface properties. Diverse film chemistries were achieved by tuning and optimizing the deposition conditions. Human-derived fibroblasts were used to confirm the biocompatibility of oxazoline derived coatings. The capacity of the coatings to resist biofilm attachment was studied as a function of deposition power and mode (i.e., continuous wave or pulsed) and precursor flow rates for both 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline. After careful tuning of the deposition parameters films having the capacity to resist biofilm formation by more than 90% were achieved. The substrate-independent and customizable properties of the new generation of plasma deposited oxazoline thin films developed in this work make them attractive candidates for the coating of medical devices and other applications where bacteria surface colonization and biofilm formation is an issue.
Contact Line Motion on Nanorough Surfaces: A Thermally Activated Process
Publisher: American Chemical Society (ACS)
Date: 03-05-2013
DOI: 10.1021/JA3104846
Abstract: The motion of a solid-liquid-liquid contact line over nanorough surfaces is investigated. The surface nanodefects are varied in size, density, and shape. The dynamics of the three-phase contact line on all nanorough substrates studied is thermally activated. However, unlike the motion of a liquid-vapor interface over smooth surfaces, this thermally activated process is not adequately described by the molecular kinetic theory. The molecular parameters extracted from the experiments suggest that on the nanorough surfaces, the motion of the contact line is unlikely to simply consist of molecular adsorption-desorption steps. Thermally activated pinning-depinning events on the surface nanodefects are also important. We investigate the effect of surface nanotopography on the relative importance of these two mechanisms in governing contact line motion. Using a derivation for the hysteresis energy based on Joanny and de Gennes's model, we evaluate the effect of nanotopographical features on the wetting activation free energy and contact line friction. Our results suggest that both solid-liquid interactions and surface pinning strength contribute to the energy barriers hindering the three-phase contact line motion. For relatively low nanodefect densities, the activation free energy of wetting can be expressed as a sum of surface wettability and surface topography contributions, thus providing a direct link between contact line dynamics and roughness parameters.
Improving hexaminolevulinate enabled cancer cell detection in liquid biopsy immunosensors
Publisher: Springer Science and Business Media LLC
Date: 31-03-2021
DOI: 10.1038/S41598-021-86649-6
Abstract: Hexaminolevulinate (HAL) induced Protoporphyrin IX (PpIX) fluorescence is commonly used to differentiate cancer cells from normal cells in vivo, as for instance in blue light cystoscopy for bladder cancer diagnosis. A detailed approach is here provided to use this diagnostic principle ex vivo in an immunosensor device, towards enabling non-invasive cancer diagnostic from body fluids, such as urine. Several factors susceptible to affect the applicability of HAL-assisted diagnosis in body fluids were tested. These included the cell viability and its impact on PpIX fluorescence, the storage condition and shelf life of HAL premix reagent, light exposure (360–450 nm wavelengths) and its corresponding effect on both intensity and bleaching of the PpIX fluorescence as a function of the microscopy imaging conditions. There was no significant decrease in the viability of bladder cancer cells after 6 h at 4 °C (student’s t-test: p 0.05). The cellular PpIX fluorescence decreased in a time-dependent manner when cancer cells were kept at 4 °C for extended period of time, though this didn’t significantly reduce the fluorescence intensity contrast between cancer and non-cancer cells kept in the same condition for 6 h. HAL premix reagent kept in long term storage at 4 °C induced stronger PpIX fluorescence than reagent kept in the − 20 °C freezer. The PpIX fluorescence was negatively affected by repeated light exposure but increased with illumination intensity and exposure time. Though this applied to both healthy and cancer cell lines, and therefore did not statistically improved the differentiation between cell types. This study revealed important experimental settings that need to be carefully considered to benefit from the analytical potential of HAL induced fluorescence when used in technologies for the diagnosis of cancer from body fluids.
Nanotopography‐Induced Unfolding of Fibrinogen Modulates Leukocyte Binding and Activation
Publisher: Wiley
Date: 20-01-2019
A Comparative Assessment of Nanoparticulate and Metallic Silver Coated Dressings
Publisher: Bentham Science Publishers Ltd.
Date: 22-04-2016
Fluid Flow Dependency in Immunoselective Cell Capture via Liquid Biopsy
Publisher: American Chemical Society (ACS)
Date: 10-2021
DOI: 10.1021/ACS.LANGMUIR.1C01998
Abstract: Liquid biopsy targets rare cells that overexpress disease-specific membrane markers and capture these cells via immunoaffinity. The diagnosis efficiency of liquid biopsy can be impaired by the presence of healthy adherent cells also expressing the same biomarkers. Here, we investigated the effect of settling times and rinsing flow rates on the efficiency of EpCAM-based immunocapture using both simulation and experiments with three different cell types. Cell-surface adhesion forces and shear rates were calculated to define the range of rinsing flow rates to test experimentally. Healthy adherent cells did not adhere to blocked immunofunctionalized surfaces within the timeframe of the experiment however, healthy EpCAM positive cells did bind to the surface to some extent. The greatest difference in capture efficiency was obtained using a high rinsing flow rate of 25 mL/min following 40 min static incubation, indicating that optimizing rinsing flow rates could be a viable option to capture, more specifically, cancer cells overexpressing EpCAM.
SURFACE CLICK REACTION BETWEEN ACETYLENE-DECORATED POLYMERIC PLATFORM AND AZIDE-DECORATED COMPOUNDS
Publisher: World Scientific Pub Co Pte Ltd
Date: 03-2023
DOI: 10.1142/S0218625X23500166
Abstract: A proof on concept study was conducted in the quest for dual-functional surfaces that provide both biopassivity and bioactivity. It presents the development of a biopassive platform that readily binds to bioactive molecules via copper-catalyzed acetylene-azide cycloaddition reaction. Acetylene-decorated poly(2-methyl-2-oxazoline) (PMOXA) brushes were grafted on an Nb 2 O 5 surface. This biopassive brush platform was then exposed to various azide-decorated compounds of different sizes (molecular weight) and chemical structure, i.e. benzyl, mannose, and antimicrobial peptide (AMP), to react through the cycloaddition reaction. The different nature of the compounds “clicked” to the brushes requires different strategies of characterization. Time of flight-secondary ion mass spectroscopy (ToF-SIMS) results showed that benzyl-triazole-characteristic fragments were successfully bound to the surface. Fluorescence spectroscopy results indicated that mannose-azide molecules tagged with dye-carrying Concanavalin A (Con-A) could bind to the PMOXA-acetylene brush via specific and, to some extent, nonspecific interactions. Similarly, optical waveguide light-mode spectroscopy (OWLS) and quartz crystal microbalance-dissipation (QCM-D) analysis showed a successful reaction between AMP-azide and the PMOXA-acetylene brush platform. Together, these results validated the original approach of generating dual-functional surfaces using a “click” reaction between oxazoline brushes and a variety of ligands relevant to a range of applications.
Plasma polymer barrier layers to control the release kinetics from dissolvable microneedle patches
Publisher: Wiley
Date: 28-07-2022
Abstract: Dissolving microneedles are a noninvasive transdermal drug delivery platform that offers painless needle‐free patient treatment. Current strategies to control the kinetics of drug release from the polymeric microneedle patches consist of adjusting the bulk polymer formulations and/or encapsulating the cargo in controlled delivery vehicles. Instead, in this study, the drug release rates were altered by modifying the surface properties of the microneedles using plasma polymer coatings with tailored properties. The main advantage of this one‐step, solvent‐free, and scalable method is that it can be applied to any type of microneedles regardless of their drug cargo or bulk material. Octadiene plasma polymer films were found to suppress the burst release effect of otherwise rapidly dissolving microneedles and to reduce the dissolution rate by a factor of four compared to uncoated control patches. The approach presented in this study offers an alternative, highly tunable, and customizable strategy for controlling drug release rate from microneedle patches.
Plasma enabled devices for the selective capture and photodynamic identification of prostate cancer cells
Publisher: American Vacuum Society
Date: 05-2020
DOI: 10.1116/6.0000047
Abstract: Prostate cancer is the second most common cancer in men and the second leading cause of male cancer deaths. The current blood test for detecting prostate cancers measures prostate-specific antigen. It has many limitations including a very high rate of false positives. Herein, prostate-specific membrane antigen (PSMA) based immunocapture and hexaminolevulinate (HAL) based photodetection are integrated into a new diagnostic device designed to selectively identify whole prostate cancer cells from voided urine with the aim of providing an accurate noninvasive alternative to current diagnosis methods. Prestained, prostate cancer cells spiked in urine s les at concentrations ranging from 1500 to 2000 cells/ml were captured with 89% sensitivity and 95% specificity. HAL, a cancer specific photosensitizer, was then used to circumvent the need for prestaining. Optimum HAL incubation conditions were identified (50 μM at 37 °C for 2 h) where the mean HAL-induced fluorescence intensity of LNCaP cells was three times that of healthy PNT2 cells, thus providing an independent way to discriminate captured cancer cells from background metabolites. Combining anti-PSMA immunocapture with HAL-induced fluorescent detection, 86% sensitivity and 88% selectivity were achieved, thereby proving the validity of the dual-method for the selective photospecific detection of prostate cancer cells.
Tuning and predicting the wetting of nanoengineered material surface
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5NR08329J
Abstract: A model predicting the wettability of nanorough substrates with re-entrant geometry is developed using substrata with controlled nanotopography and chemistry.
In order for the light to shine so brightly, the darkness must be present-why do cancers fluoresce with 5-aminolaevulinic acid?
Publisher: Springer Science and Business Media LLC
Date: 13-08-2019
Contact Line Friction in Liquid–Liquid Displacement on Hydrophobic Surfaces
Publisher: American Chemical Society (ACS)
Date: 29-11-2011
DOI: 10.1021/JP209140A
Plasma polymerised polyoxazoline thin films for biomedical applications
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5CC00260E
Abstract: We report novel solvent-free and substrate independent, plasma polymerised nanoscale biocompatible polyoxazoline coatings capable of controlling protein and cell adhesion, and significantly reducing biofilm build up.
Organic Monolayers on Si(211) for Triboelectricity Generation: Etching Optimization and Relationship between the Electrochemistry and Current Output
Publisher: American Chemical Society (ACS)
Date: 28-09-2022
Shedding Light on Bladder Cancer Diagnosis in Urine
Publisher: MDPI AG
Date: 08-06-2020
DOI: 10.3390/DIAGNOSTICS10060383
Abstract: Blue light cystoscopy (BLC) is the most recent clinical approach in the detection and diagnosis of bladder cancer, a common type of cancer with a high rate of recurrence. Representing a significant advance over previous approaches, this photodynamic diagnostic technique uses a photosensitiser prodrug as an adjunct to white light cystoscopy to enhance the in vivo detection of malignant tissues in the bladder based on their distinctive fluorescence. Whilst it does improve detection rates, BLC remains an invasive and costly procedure. Meanwhile, a variety of noninvasive urine detection methods and related microdevices have been developed, none of which have yet entered routine clinical use due to unsatisfactory sensitivity. Following a brief description of the current approaches and their limitations, we provide here a systematic review of a newer niche research aiming to develop a noninvasive adaptation of photodynamic diagnosis. The research to date surrounding the ex situ use of photosensitiser prodrugs for urinary diagnosis of bladder cancer is also discussed.
Nanoengineered Interfaces, Coatings, and Structures by Plasma Techniques
Publisher: MDPI AG
Date: 15-12-2017
DOI: 10.3390/NANO7120449
Abstract: Nanoparticles, nanotubes, nanobelts, nanoneedles, nanosheets, nanowires, nanopillars: the variety of nanostructured interfaces that can be created and modified using plasma processes is virtually endless.[...]
Cover Picture: Plasma Process. Polym. 2/2019
Publisher: Wiley
Date: 02-2019
Plasma Polymer Deposition: A Versatile Tool for Stem Cell Research
Publisher: Wiley
Date: 30-11-2016
'Chocolate' silver nanoparticles: Synthesis, antibacterial activity and cytotoxicity.
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.JCIS.2016.08.003
Abstract: Silver nanoparticles (AgNPs) have emerged as a powerful weapon against antibiotic resistant microorganisms. However, most conventional AgNPs syntheses require the use of hazardous chemicals and generate toxic organic waste. Hence, in recent year's, plant derived and biomolecule based synthetics have has gained much attention. Cacao has been used for years for its medicinal benefits and contains a powerful reducing agent - oxalic acid. We hypothesized that, due to the presence of oxalic acid, cacao extract is capable of reducing silver nitrate (AgNO3) to produce AgNPs. In this study, AgNPs were synthesized by using natural cacao extract as a reducing and stabilizing agent. The reaction temperature, time and reactant molarity were varied to optimize the synthesis yield. UV-visible spectroscopy (UV-vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM) characterization demonstrated that the synthesized AgNPs were spherical particles ranging in size from 35 to 42.5nm. The synthesized AgNPs showed significant antibacterial activity against clinically relevant pathogens such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Staphylococcus epidermidis. Importantly, these green AgNPs are not cytotoxic to human dermal fibroblasts (HDFs) at concentrations below 32μg/ml. We conclude that cacao-based synthesis is a reproducible and sustainable method for the generation of stable antimicrobial silver nanoparticles with low cytotoxicity to human cells. The AgNPs synthesized in this work have promising properties for applications in the biomedical field.
Bactericidal effects of plasma-modified surface chemistry of silicon nanograss
Publisher: IOP Publishing
Date: 05-07-2016
Binding of nanoparticles to aminated plasma polymer surfaces is controlled by primary amine density and solution pH
Publisher: American Chemical Society (ACS)
Date: 11-06-2018
Nanoengineered plasma polymer films for biomedical applications
Publisher: International Association of Advanced Materials
Date: 2018
Prostate cancer detection: a systematic review of urinary biosensors
Publisher: Springer Science and Business Media LLC
Date: 08-01-2022
DOI: 10.1038/S41391-021-00480-8
Abstract: Current diagnostic methods for prostate cancer are invasive and lack specificity towards aggressive forms of the disease, which can lead to overtreatment. A new class of non-invasive alternatives is under development, in which urinary biomarkers are detected using biosensing devices to offer rapid and accurate prostate cancer diagnosis. These different approaches are systematically reviewed and their potential for translation to clinical practice is evaluated. A systematic review of the literature was performed in May 2021 using PubMed Medline database, Embase, and Web of Science. The objective was to review the structural designs and performance of biosensors tested on urine s les from patients with prostate cancer. A total of 76 records were identified. After screening and eligibility, 14 articles were included and are discussed in this paper. The biosensors were discussed based on the target biomarkers and detection technologies used, as well as the results of the clinical studies. Most of the works reported good discrimination between patients with prostate cancer and controls. This review highlights the potential of urinary biosensors for non-invasive prostate cancer detection. However, clinical studies have so far only been conducted on small cohorts of patient, with large scale trials still needed to validate the proposed approaches. Overall, the consensus arising from the proof of concepts studies reviewed here, is that an adequate combination of biomarkers into multiplex biosensor platforms is required to achieve accurate diagnostic tests. Furthermore, whether such devices can discriminate between aggressive and indolent cancer has not yet been addressed, because it entails optimized biomarkers panels and long-term clinical trials.
Preserving the reactivity of coatings plasma deposited from oxazoline precursors − An in depth study
Publisher: Wiley
Date: 20-11-2018
Functional nanothin films plasma-deposited from 2-isopropenyl-2-oxazoline for biosensor applications
Publisher: American Vacuum Society
Date: 09-2020
DOI: 10.1116/6.0000499
Abstract: Plasma polymers derived from oxazoline precursors present a range of versatile properties that is fueling their use as biomaterials. However, coatings deposited from commonly used methyl and ethyl oxazoline precursors can be sensitive to the plasma deposition conditions. In this work, we used various spectroscopic methods (ellipsometry, x-ray photoelectron spectroscopy, and time of flight secondary ion mass spectrometry) and cell viability assays to evaluate the transferability of deposition conditions from the original plasma reactor developed by Griesser to a new wider, reactor designed for upscaled biosensors applications. The physicochemical properties, reactivity, and biocompatibility of films deposited from 2-isopropenyl-2-oxazoline were investigated. Thanks to the availability of an unsaturated pendant group, the coatings obtained from this oxazoline precursor are more stable and reproducible over a range of deposition conditions while retaining reactivity toward ligands and biomolecules. This study identified films deposited at 20 W and 0.012 mbar working pressure as being the best suited for biosensor applications.
Effect of Electric Fields on Silicon-Based Monolayers
Publisher: American Chemical Society (ACS)
Date: 27-02-2022
Protein Interactions with Nanoengineered Polyoxazoline Surfaces Generated via Plasma Deposition
Publisher: American Chemical Society (ACS)
Date: 11-07-2017
DOI: 10.1021/ACS.LANGMUIR.7B01279
Abstract: Protein adsorption to biomaterials is critical in determining their suitability for specific applications, such as implants or biosensors. Here, we show that surface nanoroughness can be tailored to control the covalent binding of proteins to plasma-deposited polyoxazoline (PPOx). Nanoengineered surfaces were created by immobilizing gold nanoparticles varying in size and surface density on PPOx films. To keep the surface chemistry consistent while preserving the nanotopography, all substrates were overcoated with a nanothin PPOx film. Bovine serum albumin was chosen to study protein interactions with the nanoengineered surfaces. The results demonstrate that the amount of protein bound to the surface is not directly correlated with the increase in surface area. Instead, it is determined by nanotopography-induced geometric effects and surface wettability. A densely packed array of 16 and 38 nm nanoparticles hinders protein adsorption compared to smooth PPOx substrates, while it increases for 68 nm nanoparticles. These adaptable surfaces could be used for designing biomaterials where proteins adsorption is or is not desirable.
Nanotopography: Nanotopography‐Induced Unfolding of Fibrinogen Modulates Leukocyte Binding and Activation (Adv. Funct. Mater. 14/2019)
Publisher: Wiley
Date: 04-2019
Advanced Biomedical Devices Facilitated by Plasma Deposited Polyoxazoline Coatings
Publisher: Juniper Publishers
Date: 24-07-2017
Cancer cell detection device for the diagnosis of bladder cancer from urine
Publisher: Elsevier BV
Date: 2021
Printable Hydrogel Arrays for Portable and High-Throughput Shear-Mediated Assays
Publisher: American Chemical Society (ACS)
Date: 20-06-2023
Bladder Cancer Cell Capture: Elucidating the Effect of Sample Storage Conditions on Capturing Bladder Cancer Cells via Surface Immobilized EpCAM Antibody.
Publisher: American Chemical Society (ACS)
Date: 06-08-2019
Abstract: The gold standard to detect bladder cancer, cystoscopy, is an invasive procedure requiring ambulant hospitalization, thus presenting an obstacle for routine diagnosis. We aim to develop a noninvasive detection method as an alternative that selectively captures shed cancer cells in the patient's urine via surface-immobilized anti-EpCAM antibody. However, the urine s le storage conditions prior to analysis affect the subsequent cancer cell capture rates by the device. In this study, we investigate the capture rates of HT1197 and HT1376 bladder cancer cells in different media (fresh and aged urine as well as PBS) and storage temperatures prior to analysis (37 and 4 °C) as well as in the presence of adjuvants in the medias (free antibodies and cell debris). Capture efficiencies decreased in as little as 1 h of the s le being incubated at 37 °C in all media studied here. Furthermore, cell debris played a strong part in reducing the capture efficiency. From the data, we conclude that storing the s le at 4 °C resulted in the best capture efficiency if storage of more than 1 h was required, which gave valuable insights for this sensor's translation from laboratory to real-world applications.
Plasma Polymer Coatings To Direct the Differentiation of Mouse Kidney-Derived Stem Cells into Podocyte and Proximal Tubule-like Cells
Publisher: American Chemical Society (ACS)
Date: 07-05-2019
Dynamics of liquid-liquid displacement
Publisher: American Chemical Society (ACS)
Date: 04-06-2009
DOI: 10.1021/LA900584S
Abstract: Capillary driven liquid-liquid displacement in a system with two immiscible liquids of comparable viscosity was investigated by means of optical high speed video microscopy. For the first time, the impact of substrate wettability on contact line dynamics in liquid-liquid systems was studied. On all substrates, qualitatively different dynamics, in two distinct velocity regimes, were found. Hydrodynamic models apply to the fast stage of initial spreading, while nonhydrodynamic dissipation dominates contact line motion in a final stage at low speed, where the molecular kinetic theory (MKT) successfully captured the dynamics. The MKT model parameter values showed no systematic dependence on substrate wettability. This unexpected result is interpreted in terms of local contact line pinning.
Effects of Supplemental Drugs on Hexaminolevulinate (HAL)-Induced PpIX Fluorescence in Bladder Cancer Cell Suspensions.
Publisher: MDPI AG
Date: 10-07-2022
DOI: 10.3390/IJMS23147631
Abstract: Seven different inhibitors of the heme metabolic pathway were applied in combination with HAL to study the formation of PpIX in bladder cancer HT1197 and normal fibroblast HFFF2 cells ex vivo, specifically with the aim to increase the fluorescence contrast between cancer and non-cancer cells. The mRNA expression of enzymes involved in the heme biosynthesis pathway were measured via PCR following incubation with the drugs in order to link the fluorescence levels and metabolic activity. The exogenous administration of HAL does lead to cancer-specific PpIX accumulation. However, the contrast between cancer and normal cells in suspension was not enhanced by the enzyme inhibitors and iron-chelating agents tested, nor did the mRNA expression necessarily correlate with the fluorescence intensity. The results indicate that a difference in the metabolic activity of cells in suspension may limit the applicability of exogenous enzyme inhibitor administration as a mean to improve the fluorescence-based detection of cancer cells shed in body fluids.
Sliding Schottky diode triboelectric nanogenerators with current output of 109 A/m2 by molecular engineering of Si(211) surfaces
Publisher: Elsevier BV
Date: 11-2022
Selective Microfluidic Capture and Detection of Prostate Cancer Cells from Urine without Digital Rectal Examination
Publisher: MDPI AG
Date: 04-11-2021
Abstract: Urine-based biomarkers have shown suitable diagnostic potential for prostate cancer (PCa) detection. Yet, until now, prostatic massage remains required prior to urine s ling. Here, we test a potential diagnostic approach using voided urine collected without prior digital rectal examination (DRE). In this study, we evaluated the diagnostic performance of a microfluidic-based platform that combines the principle of photodynamic diagnostic with immunocapture for the detection of PCa cells. The functionality and sensitivity of this platform were validated using both cultured cells and PCa patient urine s les. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) demonstrated this platform had a detection limit of fewer than 10 cells per 60 µL and successfully validated the presence of a PCa biomarker in the urine of cancer patients without prior DRE. This biosensing platform exhibits a sensitivity of 72.4% and a specificity of 71.4%, in suitable agreement with qRT-PCR data. The results of this study constitute a stepping stone in the future development of noninvasive prostate cancer diagnostic technologies that do not require DRE.
Questions and Answers on the Wettability of Nano‐Engineered Surfaces
Publisher: Wiley
Date: 31-07-2017
Advances of nanotechnologies for hydraulic fracturing of coal seam gas reservoirs: potential applications and some limitations in Australia
Publisher: Springer Science and Business Media LLC
Date: 26-04-2022
DOI: 10.1007/S40789-022-00497-X
Abstract: Some of the most promising potential applications of nanotechnology to hydraulic fracturing of coal seam gas (CSG) are reviewed with a focus on Australian CSG wells. Three propitious applications were identified: (1) Nanoparticle enhanced viscoelastic surfactants (VES) fracturing fluids to prevent fluid loss by up to 30%, made possible by the formation of pseudo-filter cakes and reducing the viscosity of the VES fluids. Besides, there is no requirement of clay control additives or biocides. (2) Nano-proppants to extend fracture networks and reduce proppant embedment by introducing them prior to the emplacement of larger proppants. Fly Ash nanoparticles can be particularly effective because of their high sphericity and mechanical strength. (3) Nanoparticle-coated proppants, to mitigate the migration of particle fines by restricting them close to their source by adsorption, with MgO being the most effective. The use of nanotechnology in hydraulic fracturing applications is currently hindered due to a discordant regulatory environment compounded by the cost of the nanoparticles themselves, as well as, a lack of field data to validate the technology under real downhole conditions. Although the necessary field tests are unlikely to be conducted for as long as abundant natural gas is available, exploratory studies could pave the way for future applications. Graphical abstract
On-Surface Azide–Alkyne Cycloaddition Reaction: Does It Click with Ruthenium Catalysts?
Publisher: American Chemical Society (ACS)
Date: 26-04-2022
Self-sterilizing antibacterial silver-loaded microneedles
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8CC06035E
Abstract: Here we report the development of slef-sterilizing dissolving microneedles, a promising vehicle for vaccine and drug delivery.
Electrochemical behavior of oxazoline-based plasma polymers for biosensing applications
Publisher: Wiley
Date: 25-04-2023
Abstract: Plasma‐polymerized polyoxazoline (POx) thin films offer a fast, scalable, and solvent‐free method of electrode functionalization through the unique chemistry of the oxazoline ring. However, for POx to be a viable green alternative to existing surface modification approaches, the films should be able to withstand the processing steps involved in biosensing. Here, the effects that current exposure, extended incubation, and repeated electrode rinses have on the electrochemical and physical stability of polymethyloxazoline thin films are investigated. The films are observed to become more diffusive after incubation and rinse steps. While no significant changes in chemistry were observed, a marked change in nanotopography occurred after exposure to current, suggesting a change in the polymer film structure.
Probing Hexaminolevulinate Mediated PpIX Fluorescence in Cancer Cell Suspensions in the Presence of Chemical Adjuvants
Publisher: MDPI AG
Date: 22-04-2020
DOI: 10.3390/IJMS21082963
Abstract: Exogenous administration of hexaminolevulinate (HAL) induces fluorescent protoporphyrin IX (PpIX) accumulation preferentially in cancer cells. However, the PpIX fluorescence intensities between noncancer and cancer cells are highly variable. The contrast between cancer and noncancer cells may be insufficient to reliably discriminate, especially at the single cell level in cancer diagnostics. This study examines the use of the chemical adjuvants dimethylsulphoxide (DMSO) or deferoxamine (DFO) to enhance the HAL induced PpIX accumulation in cancer cells. Our results showed that in some of the incubation conditions tested, the addition of DFO with HAL significantly increased PpIX 21 fluorescence of adherent monolayer cancer cells, but this was never the case for cells in suspension. Permeabilisation with DMSO did not increase PpIX fluorescence. Cell-to-cell interaction may well play an important role in the PpIX accumulation when suspended cells are treated in HAL and adjuvant chemicals.
Surface nanotopography guides kidney-derived stem cell differentiation into podocytes
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.ACTBIO.2017.02.036
Abstract: Stem cells have enormous potential for developing novel therapies for kidney disease but our current inability to direct their differentiation to specialised renal cells presents a barrier to their use in renal bioengineering and drug development programmes. Here, a plasma-based technology was used to produce a range of biocompatible substrates comprising controlled surface nanotopography and tailored outermost chemical functionalities. These novel substrata were used to investigate the response of mouse kidney-derived stem cells to changes in both substrate nanotopography and surface chemistry. The stem cells proliferated to a similar extent on all substrates, but specific combinations of nanotopography and surface chemistry promoted differentiation into either podocyte or proximal tubule-like cells. The data reveal that high density of surface nanodefects in association with amine rich chemistry primarily lead to differentiation into podocytes while surfaces with low amine content constituted better substrates for differentiation into proximal tubule cells regardless of the surface nanotopographic profile. Thus plasma coated nanorough substrate may provide useful platform for guiding the fate kidney stem cell in vitro. Adult kidney-derived stem cells have been identified as a promising way to regenerate damaged nephrons. Artificial growth platforms capable to guide the stem cells differentiation into useful cell lineages are needed to expand regenerative cell therapies for chronic kidney diseases. Chemically homogeneous growth substrates endowed with nanotopography gradients were generated via plasma assisted methods in order to investigate the effect of physical cues on the proliferation and differentiation of kidney-derived stem cells. For the first time it is shown that the surface density of the nano-structures had a greater impact on fate of the stem cells than their size. Careful design of the growth substrate nanotopography may help directing the differentiation into either podocytes or proximal tubule cells.
Deposition of 2‐oxazoline‐based plasma polymer coatings using atmospheric pressure helium plasma jet
Publisher: Wiley
Date: 08-2019
Cover Picture: Plasma Process. Polym. 10/2019
Publisher: Wiley
Date: 10-2019
Plasma nanoengineering and nanofabrication
Publisher: MDPI AG
Date: 23-06-2016
DOI: 10.3390/NANO6070122
The influence of topography on dynamic wetting
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.CIS.2013.04.005
Abstract: The paramount importance of wetting applications and the significant economic value of controlling wetting-based industrial processes has stimulated a deep interest in wetting science. In many industrial applications the motion of a complex liquid front over nano-textured surfaces controls the fate of the processes. However our knowledge of the impact of nano-heterogeneities on static and dynamic wetting is very limited. In this article, the fundamentals of wetting are briefly reviewed, with a particular focus on hysteresis and roughness issues. Present knowledge and models of dynamic wetting on smooth and rough surfaces are then examined, with particular attention devoted to the case of nano-topographical heterogeneities and solid-fluid-fluid systems.
Biosensor device for the photo-specific detection of immuno-captured bladder cancer cells using hexaminolevulinate: An ex-vivo study
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.PDPDT.2019.08.001
Abstract: Exogenous administration of the photodynamic agent hexaminolevulinate induces Protoporphyrin IX (PpIX) accumulation in malignant tissue. This may enable differentiation from healthy tissues by emission of a distinctive red fluorescence. It provides the photo-specific detection when excited with blue light at 405 nm. This study determines the ex-vivo processing conditions (time, concentration, temperature and addition of a fluorescent dye) required for HAL-induced PpIX fluorescence to successfully discriminate between bladder cancer and benign fibroblast cells shed in urine at the single cell level. HAL-induced fluorescence was 4.5 times brighter in cancer cells than non-cancer cells when incubated in the optimum conditions, and could be used to correctly identified bladder cancer cells captured within a newly developed immunofunctionalized biosensor with 88% efficiency. This biosensor is designed to facilitate the immuno-capture of cancer cells by interaction with carcinoma specific anti Epithelial Cell Adhesion molecule (anti-EpCAM) antibodies. Anti-EpCAM antibodies were immobilized on polyoxazoline (POx) plasma polymers by covalent bonds in microfluidic channels. Combining photodynamic and immunoselective approach therefore constitute a promising approach for the non-invasive diagnosis of bladder cancer with two independent level of confidence. This study investigate the relationship between different regulatory factors (time, concentration, temperature and addition of a fluorescent dye) and Hexaminolevulinate (HAL)-mediated photodynamic diagnosis of bladder cancer (PDD) in vitro. We examine the natural photosensitizer Protoporphyrin IX (PpIX) fluorescence induced by HAL in several human bladder cancer cell lines and one non-cancer foreskin fibroblast cell line and identify the processing conditions that maximise the difference in fluorescence intensity between malign and benign cell types. The detection of HAL induced fluorescence at a single cell level by a selective cancer cell capture platform is also tested. Experiments were performed on cultured monolayer cells and cells in suspension. The cell lines examined included the transitional epithelium carcinoma cell lines HT1197, HT1376, EJ138 and RT4, and the non-cancer foreskin fibroblasts HFF. Cells were incubated with HAL in various doses, time and temperature settings. We also used the nuclear red as a tool to study the PpIX subcellular localization. PpIX fluorescence intensities were measured and analysed using fluorescence microscope software. Finally, we evaluated the possibility of using HAL to discriminate between cancer and non-cancer cells from a mixed cell population using a newly developed immunofunctionalized microfluidic platform. The accumulation of PpIX in bladder cancer cells was significantly higher than in non-cancer cells, both cultured monolayer cells and cells in suspension. Effectively, the fluorescence intensity was 4.5 times brighter in bladder cancer cells than non-cancer foreskin fibroblast cells when incubated in the optimum condition, in which the nuclear stain adjuvant acted as a fluorescence enhancer. Cancer cells displayed PpIX accumulated mainly in mitochondria but none or very little PpIX was observed in non-cancer cells. HAL-induced fluorescence could be used to correctly identify bladder cancer cells within the EpCAM conjugated POx based microfluidic sensor with an 88% capture selectivity rate. These findings prove that the application of HAL-induced PpIX fluorescence can successfully distinguish between cancer and non-cancer cells in vitro. This test can provide advanced second level of confidence on the cancerous nature of cells captured by the immunofunctionalized bladder cancer diagnostic platform.
Properties and reactivity of polyoxazoline plasma polymer films
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TB00901D
Abstract: Nanoscale polyoxazoline coatings generated via a single step plasma deposition process are investigated. The complex functionality of the film can be controlled by varying the deposition conditions. Partial retention of the oxazoline ring facilitates covalent binding of nanoparticles and biomolecules.
Plasma deposited polyoxazoline films integration into spiral microfluidics for the targeted capture of size selected cells
Publisher: Frontiers Media SA
Date: 20-05-2021
DOI: 10.3389/FCHEM.2021.690781
Abstract: Biomolecules readily and irreversibly bind to plasma deposited Polyoxazoline thin films in physiological conditions. The unique reactivity of these thin films toward antibodies is driving the development of immunosensing platforms for applications in cancer diagnostics. However, in order for these coatings to be used as advanced immunosensors, they need to be incorporated into microfluidic devices that are sealed via plasma bonding. In this work, the thickness, chemistry and reactivity of the polyoxazoline films were assessed following plasma activation. Films deposited from methyl and isopropenyl oxazoline precursors were integrated into spiral microfluidic devices and biofunctionalized with prostate cancer specific antibodies. Using microbeads as model particles, the design of the spiral microfluidic was optimised to enable the size-based isolation of cancer cells. The device was tested with a mixed cell suspension of healthy and malignant prostate cells. The results showed that, following size-specific separation in the spiral, selective capture was achieved on the immunofunctionalised PPOx surface. This proof of concept study demonstrates that plasma deposited polyoxazoline can be used for immunosensing in plasma bonded microfluidic devices.
Plasma deposition of organic polymer films for solar cell applications
Publisher: Elsevier BV
Date: 05-2016
Nanoroughness Impact on Liquid–Liquid Displacement
Publisher: American Chemical Society (ACS)
Date: 10-05-2012
DOI: 10.1021/JP2120274
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