ORCID Profile
0000-0002-4593-1170
Current Organisation
Monash 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)
Synthesis of Materials | Macromolecular and Materials Chemistry | Polymers and Plastics | Pharmaceutical Sciences | Nanomaterials | Nanomedicine | Nanotechnology | Functional Materials | Colloid And Surface Chemistry | Nanotechnology | Materials Engineering | Physical Chemistry (Incl. Structural) | Optical Physics Not Elsewhere Classified |
ANZSRC Socio-Economic Objective (SEO)
Human Pharmaceutical Treatments (e.g. Antibiotics) | Expanding Knowledge in the Chemical Sciences | Veterinary Pharmaceutical Treatments (e.g. Antibiotics) | Polymeric Materials (e.g. Paints) | Expanding Knowledge in the Physical Sciences | Cancer and Related Disorders | Crop Protection Chemicals | Prevention—biologicals (e.g. vaccines) | Diagnostics | Scientific instrumentation | Expanding Knowledge in Technology
Related Links
Publications
Reversible addition–fragmentation chain transfer polymerization initiated with γ-radiation at ambient temperature: an overview
Publisher: Elsevier BV
Date: 03-2003
Kinetic investigations of reversible addition fragmentation chain transfer polymerizations: Cumyl phenyldithioacetate mediated homopolymerizations of styrene and methyl methacrylate
Publisher: American Chemical Society (ACS)
Date: 29-09-2001
DOI: 10.1021/MA010349M
Polyelectrolyte functionalization of electrospun fibers
Publisher: American Chemical Society (ACS)
Date: 29-03-2006
DOI: 10.1021/CM052760K
Lipidated polymers for the stabilization of cubosomes: nanostructured drug delivery vehicles
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CC05842J
Abstract: We report a straightforward approach for preparing polymers with lipidic chain ends, and show their application in stabilising nanostructured drug delivery vehicles.
Long‐lived intermediates in reversible addition–fragmentation chain‐transfer (RAFT) polymerization generated by γ radiation
Publisher: Wiley
Date: 03-2002
DOI: 10.1002/POLA.10194
Influence of Size and Shape on the Biodistribution of Nanoparticles Prepared by Polymerization-Induced Self-Assembly
Publisher: American Chemical Society (ACS)
Date: 29-09-2017
DOI: 10.1021/ACS.BIOMAC.7B00995
Abstract: Polymerization-induced self-assembly (PISA) is a facile one-pot synthetic technique for preparing polymeric nanoparticles with different sizes and shapes for application in a variety of fields including nanomedicine. However, the in vivo biodistribution of nanoparticles obtained by PISA still remains unclear. To address this knowledge gap, we report the synthesis, cytotoxicity, and biodistribution in an in vivo tumor-bearing mouse model of polystyrene micelles with various sizes and polystyrene filomicelles with different lengths prepared by PISA. First, a library of nanoparticles was prepared comprised of poly(glycidyl methacrylate)-b-poly(oligo(ethylene glycol) methyl ether methacrylate)-b-polystyrene polymers, and their size and morphology were tuned by varying the polystyrene block length without affecting the surface chemistry. The
The use of endogenous gaseous molecules (NO and CO2) to regulate the self-assembly of a dual-responsive triblock copolymer
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4PY01678E
Abstract: A nitric oxide (NO) and carbon dioxide (CO 2 ) dual-responsive block copolymer was self-assembled in aqueous solution upon gas stimuli to form nanostructures.
Modular photo-induced RAFT polymerised hydrogels via thiol-ene click chemistry for 3D cell culturing
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7PY01038A
Abstract: Visible-light induced thiol–ene click gelation of RAFT polymers, creating a modular hydrogel system for 3D cell culture assays.
PH-Responsive copolymer micelles to enhance itraconazole efficacy against: Candida albicans biofilms
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9TB02586C
Abstract: Candida albicans ( C. albicans ) is a common fungal pathogen causing both localised and systemic infections.
Synthesis of well-defined poly(acrylates) in ionic liquids via copper(II)-mediated photoinduced living radical polymerization
Publisher: American Chemical Society (ACS)
Date: 27-07-2015
Development of a shape-controlled H2S delivery system using epoxide-functional nanoparticles
Publisher: Wiley
Date: 23-04-2019
DOI: 10.1002/POLA.29382
H2S-Donating trisulfide linkers confer unexpected biological behaviour to poly(ethylene glycol)-cholesteryl conjugates
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9TB02614B
Abstract: A comprehensive in vitro study into trisulfide-bearing PEG-conjugates was conducted. For these materials the combination of a cholesteryl group and an H 2 S donating moiety is required to confer cytoprotective and ROS-mitigating effects.
Recent advances in magnetic nanoparticle-based molecular probes for hepatocellular carcinoma diagnosis and therapy.
Publisher: Bentham Science Publishers Ltd.
Date: 15-10-2018
DOI: 10.2174/1381612824666180516111939
Abstract: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, leading to the second most likely cause of cancer-related deaths. Medical imaging is crucial in clinic for HCC screening and diagnosis. Due to the relatively high special resolution and excellent sensitivity, magnetic resonance imaging (MRI) by using magnetic nanoparticle-based contrast agents has been used so far in HCC imaging and staging, demonstrating great potential and promising in vivo applications. This review focuses on the use of different magnetic nanoparticles for construction of HCC nanoprobes for MR imaging and theranostic purpose.
Zinc–Epigallocatechin-3-gallate Network-Coated Nanocomposites against the Pathogenesis of Amyloid-Beta
Publisher: American Chemical Society (ACS)
Date: 02-2023
Living free radical polymerisation under a constant source of gamma radiation - An example of reversible addition-fragmentation chain transfer or reversible termination?
Publisher: Wiley
Date: 08-2002
DOI: 10.1002/1521-3927(20020801)23:12<717::AID-MARC717>3.0.CO;2-I
Polyelectrolyte blend multilayers: A versatile route to engineering interfaces and films
Publisher: Wiley
Date: 11-12-2008
Modeling the reversible addition-fragmentation chain transfer process in cumyl dithiobenzoate-mediated styrene homopolymerizations: Assessing rate coefficients for the addition-fragmentation equilibrium
Publisher: Wiley
Date: 14-03-2001
DOI: 10.1002/POLA.1112
Synthesis of Thermoresponsive, Catechol-Rich Poly(ethylene glycol) Brush Polymers for Attenuating Cellular Oxidative Stress
Publisher: American Chemical Society (ACS)
Date: 05-12-2022
Microgel stars via Reversible Addition Fragmentation Chain Transfer (RAFT) polymerisation - a facile route to macroporous membranes, honeycomb patterned thin films and inverse opal substrates
Publisher: Royal Society of Chemistry (RSC)
Date: 2003
DOI: 10.1039/B304208C
A tunable one-pot three-component synthesis of an125I and Gd-labelled star polymer nanoparticle for hybrid imaging with MRI and nuclear medicine
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8PY00621K
Abstract: Bimodal radioiodine/Gd labelled polymeric nanoparticles prepared using a versatile one-step three-component click reaction.
Precise control of drug loading and release of an NSAID–polymer conjugate for long term osteoarthritis intra-articular drug delivery
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7TB01518F
Abstract: The synthesis of biocompatible polymer diclofenac conjugates (PDCs) that have a high drug loading and high degree of control over diclofenac (DCF) release is described.
Disulfide cross-linked polymer capsules: En route to biodeconstructible systems
Publisher: American Chemical Society (ACS)
Date: 10-12-2006
DOI: 10.1021/BM050832V
Abstract: Hydrogen-bonded multilayer thin films were constructed using poly(vinylpyrrolidone) and poly(methacrylic acid) functionalized with cysteamine. The resulting films included thiol moieties that were cross-linked to render the films stable at physiological pH. Film buildup was followed using quartz crystal microgravimetry, which was also used to demonstrate the improved stability imparted by reacting the thiol moieties to form disulfide bonds. Films without disulfide bonds were readily deconstructed at physiological pH, while those with disulfide bonds were swollen upon exposure to this pH (7) but remained intact. Addition of a common thiol-disulfide exchange reagent, dithiothreitol (DTT) at pH 7 led to disassembly of the multilayer films. The films were also prepared on colloidal substrates (as demonstrated using confocal microscopy) and were used to retain a model drug (fluorescently labeled transferrin) and release this molecule when triggered by the addition of DTT. This approach has potential for the in vivo applications of hollow capsules, as thiol-disulfide exchange leading to deconstruction of the capsules can occur with the assistance of intracellular proteins.
Origin of inhibition effects in the reversible addition fragmentation chain transfer (RAFT) polymerization of methyl acrylate
Publisher: American Chemical Society (ACS)
Date: 21-09-2002
DOI: 10.1021/MA0203445
Bioconjugation and Fluorescence Labeling of Iron Oxide Nanoparticles Grafted with Bromomaleimide-Terminal Polymers
Publisher: American Chemical Society (ACS)
Date: 11-10-2018
DOI: 10.1021/ACS.BIOMAC.8B01282
Abstract: Iron oxide nanoparticles have been widely applied in biomedical applications for their unique physical properties. Despite the relatively mature synthetic approaches for iron oxide nanoparticles, surface modification strategies for obtaining particles with satisfactory biofunctionality are still urgently needed to meet the challenge of nanomedicine. Herein, we report a surface modification and biofunctionalization strategy for iron oxide-based magnetic nanoparticles based on a dibromomaleimide (DBM)-terminated polymer with brushed polyethylene glycol (PEG) chains. PEG acrylate and phosphonate monomers, serving as antibiofouling and surface anchoring compartments for iron oxide nanoparticles, were incorporated utilizing a novel DBM containing reversible addition-fragmentation chain transfer (RAFT) agent. The particles prepared through this new surface architecture possessed high colloidal stability in a physiological buffer and the capacity of covalent conjugation with biomolecules for targeting. Cell tracking of the molecular probes was achieved concomitantly by exploiting DBM conjugation-induced fluorescence of the nanoparticles.
Multivalent-ion-mediated stabilization of hydrogen-bonded multilayers
Publisher: Wiley
Date: 06-06-2006
An optimised Cu(0)-RDRP approach for the synthesis of lipidated oligomeric vinyl azlactone: Toward a versatile antimicrobial materials screening platform
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TB01624D
Abstract: For the first time Cu(0)-RDRP conditions were optimised to allow for the fast and controlled polymerisation of vinyl azlactone with tuneable lipid elements: a versatile platform material for the high-throughput synthesis of antimicrobial materials.
Tailoring the interfaces between nematic liquid crystal emulsions and aqueous phases via layer-by-layer assembly
Publisher: American Chemical Society (ACS)
Date: 12-09-2006
DOI: 10.1021/NL061604P
Abstract: We report the assembly of polyelectrolyte multilayer (PEM) films at the interfaces of thermotropic liquid crystal (LC) droplets dispersed in an aqueous phase. Exposure of PEM-coated droplets to surfactant slowed the bipolar-to-radial ordering transition of the LCs by 2 orders of magnitude relative to naked droplets. This shows that PEMs can be used to influence the interactions of analytes with the LC cores of the droplets, allowing tuning of the LC emulsion sensing properties.
Cationic acrylate oligomers comprising amino acid mimic moieties demonstrate improved antibacterial killing efficiency
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6TB02787C
Abstract: A new class of oligomeric cationic polymers with lipophilic tails were developed as antibacterial lipopeptide mimics, and revealed structurally dependent bacterial killing.
Organic arsenicals as efficient and highly specific linkers for protein/peptide-polymer conjugation
Publisher: American Chemical Society (ACS)
Date: 20-03-2015
DOI: 10.1021/JACS.5B01140
Abstract: The entropy-driven affinity of trivalent (in)organic arsenicals for closely spaced dithiols has been exploited to develop a novel route to peptide rotein-polymer conjugation. A trivalent arsenous acid (As(III)) derivative (1) obtained from p-arsanilic acid (As(V)) was shown to readily undergo conjugation to the therapeutic peptide salmon calcitonin (sCT) via bridging of the Cys(1)-Cys(7) disulfide, which was verified by RP-HPLC and MALDI-ToF-MS. Conjugation was shown to proceed rapidly (t < 2 min) in situ and stoichiometrically through sequential reduction-conjugation protocols, therefore exhibiting conjugation efficiencies equivalent to those reported for the current leading disulfide-bond targeting strategies. Furthermore, using bovine serum albumin as a model protein, the trivalent organic arsenical 1 was found to demonstrate enhanced specificity for disulfide-bond bridging in the presence of free cysteine residues relative to established maleimide functional reagents. This specificity represents a shift toward potential orthogonality, by clearly distinguishing between the reactivity of mono- and disulfide-derived (vicinal or neighbors-through-space) dithiols. Finally, p-arsanilic acid was transformed into an initiator for aqueous single electron-transfer living radical polymerization, allowing the synthesis of hydrophilic arsenic-functional polymers which were shown to exhibit negligible cytotoxicity relative to a small molecule organic arsenical, and an unfunctionalized polymer control. Poly(poly[ethylene glycol] methyl ether acrylate) (PPEGA480, DPn = 10, Mn,NMR = 4900 g·mol(-1), Đ = 1.07) possessing a pentavalent arsenic acid (As(V)) α-chain end was transformed into trivalent As(III) post-polymerization via initial reduction by biological reducing agent glutathione (GSH), followed by binding of GSH. Conjugation of the resulting As(III)-functional polymer to sCT was realized within 35 min as indicated by RP-HPLC and verified later by thermodynamically driven release of sCT, from the conjugate, in the presence of strong chelating reagent ethanedithiol.
Star Polymers Reduce Islet Amyloid Polypeptide Toxicity via Accelerated Amyloid Aggregation
Publisher: American Chemical Society (ACS)
Date: 31-10-2017
Exploiting Macromolecular Design to Optimize the Antibacterial Activity of Alkylated Cationic Oligomers
Publisher: American Chemical Society (ACS)
Date: 25-10-2018
DOI: 10.1021/ACS.BIOMAC.8B01317
Abstract: There is growing interest in synthetic polymers which co-opt the structural features of naturally occurring antimicrobial peptides. However, our understanding of how macromolecular architecture affects antibacterial activity remains limited. To address this, we investigated whether varying architectures of a series of block and statistical co-oligomers influenced antibacterial and hemolytic activity. Cu(0)-mediated polymerization was used to synthesize oligomers constituting 2-(Boc-amino)ethyl acrylate units and either diethylene glycol ethyl ether acrylate (DEGEEA) or poly(ethylene glycol) methyl ether acrylate units with varying macromolecular architecture subsequent deprotection produced primary amine functional oligomers. Further guanylation provided an additional series of antimicrobial candidates. Both chemical composition and macromolecular architecture were shown to affect antimicrobial activity. A broad spectrum antibacterial oligomer (containing guanidine moieties and DEGEEA units) was identified that possessed promising activity (MIC = 2 μg mL
Colloid surface engineering via deposition of multilayered thin films from polyelectrolyte blend solutions
Publisher: American Chemical Society (ACS)
Date: 16-04-2005
DOI: 10.1021/LA047156N
Abstract: Multilayer thin films were constructed on polystyrene colloidal particles by depositing alternating layers of poly(allylamine hydrochloride) (PAH) at pH 7.5 and varying composition blends of poly(acrylic acid) (PAA) and poly(styrenesulfonate) (PSS) at pH 3.5. Following the deposition of each layer, microelectrophoresis experiments showed alternating zeta-potentials, suggesting the formation of multilayered films on the particles. Scanning and transmission electron microscopy were used to examine the surface morphology of the colloidal particles, with homogeneous surface coatings apparent for films deposited from PAA/PSS blend solutions containing up to 90 wt % PAA. The colloidal stability of these particles is greater than those coated with in idual PAH and PAA layers. In the case of the blend PAA/PSS = 25:75 wt %, up to 20 layers were assembled without compromising the colloidal stability of the dispersion. The results demonstrate that the deposition of layers from PE blend solutions containing a strong and weak PE can be used as a facile method for controlling the surface properties and hence the colloidal stability of core-shell particles, as well as the thickness and morphology of the coatings. Control of these parameters is important for subsequent processing and application of these particles in controlled delivery, photonics, catalytic, and separation applications.
Assembly of ultrathin polymer multilayer films by click chemistry
Publisher: American Chemical Society (ACS)
Date: 28-06-2006
DOI: 10.1021/JA063043+
Abstract: Layer-by-layer (LbL) assembly is a versatile and robust technique for fabricating tailored thin films of erse composition. Herein we report a new method of covalent coupling, click chemistry, to facilitate the LbL assembly of thin films. Linear film growth was observed using both UV-vis and FTIR spectroscopy, and film thicknesses were determined by ellipsometry and atomic force microscopy. The assembled films are shown to be stable in a wide pH range. This technique offers the potential to enable the synthesis of new types of stable and responsive LbL films from a variety of polymers.
Layer-by-layer assembly of nanoblended thin films: Poly(allylamine hydrochloride) and a binary mixture of a synthetic and natural polyelectrolyte
Publisher: American Chemical Society (ACS)
Date: 31-07-2004
DOI: 10.1021/MA0490698
Thiol-Reactive Star Polymers Display Enhanced Association with Distinct Human Blood Components
Publisher: American Chemical Society (ACS)
Date: 03-04-2017
Abstract: Directing nanoparticles to specific cell types using nonantibody-based methods is of increasing interest. Thiol-reactive nanoparticles can enhance the efficiency of cargo delivery into specific cells through interactions with cell-surface proteins. However, studies to date using this technique have been largely limited to immortalized cell lines or rodents, and the utility of this technology on primary human cells is unknown. Herein, we used RAFT polymerization to prepare pyridyl disulfide (PDS)-functionalized star polymers with a methoxy-poly(ethylene glycol) brush corona and a fluorescently labeled cross-linked core using an arm-first method. PDS star polymers were examined for their interaction with primary human blood components: six separate white blood cell subsets, as well as red blood cells and platelets. Compared with control star polymers, thiol-reactive nanoparticles displayed enhanced association with white blood cells at 37 °C, particularly the phagocytic monocyte, granulocyte, and dendritic cell subsets. Platelets associated with more PDS than control nanoparticles at both 37 °C and on ice, but they were not activated in the duration examined. Association with red blood cells was minor but still enhanced with PDS nanoparticles. Thiol-reactive nanoparticles represent a useful strategy to target primary human immune cell subsets for improved nanoparticle delivery.
Assembly of multilayer films from polyelectrolytes containing weak and strong acid moieties
Publisher: American Chemical Society (ACS)
Date: 19-08-2005
DOI: 10.1021/LA051197H
Abstract: Multilayer films were assembled from a copolymer containing both weakly and strongly charged pendant groups, poly(4-styrenesulfonic acid-co-maleic acid) (PSSMA), deposited in alternation with poly(allylamine hydrochloride) (PAH). The strongly charged groups (styrene sulfonate, SS) are expected to form electrostatic linkages (to enhance film stability), while the weakly charged groups (maleic acid, MA) can alter multilayer film properties because they are responsive to external pH changes. In this study, we varied several assembly conditions such as pH, SS/MA ratio in PSSMA, and the ionic strength of the polyelectrolyte solutions. The multilayer films were also treated by immersion into pH 2 and 11 solutions after assembly. Quartz crystal microgravimetry and UV-visible spectrophotometry showed that the thickness of PSSMA/PAH multilayers decreases with increasing assembly pH regardless of whether salt was present in the polyelectrolyte solutions. When no salt was added, the multilayers are thinner, smoother, and grow less regularly. Atomic force microscopy images indicate that the presence of salt in polyelectrolyte solutions results in rougher surface morphologies, and this effect is especially significant in multilayers assembled at pH 2 and pH 11. When both polyelectrolytes are adsorbed at conditions where they are highly charged, salt was necessary to promote regular multilayer growth. Fourier transform infrared spectroscopy studies show that the carboxylic acids in the multilayers are essentially ionized when assembled from different pHs in 0.5 M sodium chloride solutions, whereas some carboxylic acids remain protonated in the multilayers assembled from solutions with no added salt. This resulted in different pH stability regimes when the multilayers were exposed to different pH solutions, post assembly.
Utilizing QCM-D To Characterize the Adhesive Mucilage Secreted by Two Marine Diatom Species in-Situ and in Real-Time
Publisher: American Chemical Society (ACS)
Date: 03-10-2006
DOI: 10.1021/BM0605661
Abstract: The quartz crystal microbalance with dissipation monitoring (QCM-D) was used to monitor the deposition of adhesive extracellular polymeric substances (EPS) employed by the marine biofouling diatoms Craspedostauros australis Cox and Amphora coffeaeformis Cleve during initial adhesion and subsequent motility. Upon injection into the QCM chamber, initial negative frequency (f) shifts and positive dissipation (D) shifts were measured that correlated to cells impacting and adhering to the QCM sensor surface. Following this "initial adhesion" response, f continued to decrease while D increased logarithmically. Rather than the result of any cell morphological alterations at the substrate surface, the shifts were correlated to the time-dependent deposition of EPS upon the substrate surface as a result of cellular motility, or gliding. Experiments utilizing comparable cell concentrations of the diatom species C. australis and A. coffeaeformis revealed significant differences between the parameter responses recorded, where A. coffeaeformis produced Deltaf and DeltaD values of -32 Hz and 6.6, and C. australis produced values of -82 Hz and 42, respectively, after 20 h post-inoculation. The viscoelastic properties of the adhered EPS adlayer from both species were examined via a Deltaf/DeltaD plot, providing reproducible signature "ratio" values for each species that likely correlate to differences in EPS interactions with the substrate that may be associated directly to differences in the fouling potential of the two species. There is a distinct lack of knowledge regarding the chemical nature of the adhesive polymers engaged, and few quantitative techniques are applicable to the study of diatom EPS. We propose that QCM-D may be a useful tool in identifying differences in the EPS employed by diatoms of different fouling potential.
Polymers with Dithiobenzoate End Groups Constitutively Release Hydrogen Sulfide upon Exposure to Cysteine and Homocysteine
Publisher: American Chemical Society (ACS)
Date: 26-03-2020
Facile access to thermoresponsive filomicelles with tuneable cores
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CC00900J
Abstract: Thermoresponsive nanoworms with tuneable cores prepared via aqueous RAFT-mediated emulsion polymerizations and temperature-induced morphological transformation (TIMT) technique.
Antibacterial low molecular weight cationic polymers: dissecting the contribution of hydrophobicity, chain length and charge to activity
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5RA24361K
Abstract: We report the antibacterial activity of a novel class of low molecular weight cationic polymers synthesised using Cu(0) mediated polymerisation.
Facile production of nanoaggregates with tuneable morphologies from thermoresponsive P(DEGMA-co-HPMA)
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5PY01467K
Abstract: RAFT-mediated emulsion polymerization of styrene and subsequent morphological transition produces nanoaggregates with tuneable morphologies.
Ambient temperature reversible addition–fragmentation chain transfer polymerisation
Publisher: Royal Society of Chemistry (RSC)
Date: 2001
DOI: 10.1039/B101794M
Thermoresponsive nanoassemblies: Layer-by-layer assembly of hydrophilic-hydrophobic alternating copolymers
Publisher: American Chemical Society (ACS)
Date: 11-03-2005
DOI: 10.1021/MA047414N
Molecular weight fractionation of poly(methyl methacrylate) using Gas Anti-Solvent techniques
Publisher: Elsevier BV
Date: 06-2003
Surfactant-free RAFT emulsion polymerization using a novel biocompatible thermoresponsive polymer
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6PY02158A
Abstract: A facile, high-scale, and versatile technique to prepare biocompatible nanoparticles with tailorable properties from thermoresponsive macro-CTAs and macro-stabilizers.
Intra-articular Treatment of Osteoarthritis with Diclofenac-Conjugated Polymer Reduces Inflammation and Pain
Publisher: American Chemical Society (ACS)
Date: 24-05-2019
Abstract: The most common treatment for osteoarthritis is daily oral administration of a nonsteroidal anti-inflammatory drug such as diclofenac. This daily dosage regime is often associated with severe side effects. In this study, we explored the potential of utilizing a high molecular weight cross-linked polyurethane polymer covalently linked to diclofenac (
Recent advances in the delivery of hydrogen sulfide via a macromolecular approach
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8PY00938D
Abstract: This mini review highlights recent advances in the design of macromolecular materials that can deliver hydrogen sulfide either spontaneously or in response to chemical and physical triggers.
Aerosol delivery of star polymer-siRNA nanoparticles as a therapeutic strategy to inhibit lung tumor growth
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.BIOMATERIALS.2022.121539
Abstract: Lung cancer is a major contributor to cancer-related death worldwide. siRNA nanomedicines are powerful tools for cancer therapeutics. However, there are challenges to overcome to increase siRNA delivery to solid tumors, including penetration of nanoparticles into a complex microenvironment following systemic delivery while avoiding rapid clearance by the reticuloendothelial system, and limited siRNA release from endosomes once inside the cell. Here we characterized cell uptake, intracellular trafficking, and gene silencing activity of miktoarm star polymer (PDMAEMA-POEGMA) nanoparticles (star nanoparticles) complexed to siRNA in lung cancer cells. We investigated the potential of nebulized star-siRNA nanoparticles to accumulate into orthotopic mouse lung tumors to inhibit expression of two genes [βIII-tubulin, Polo-Like Kinase 1 (PLK1)] which: 1) are upregulated in lung cancer cells 2) promote tumor growth and 3) are difficult to inhibit using chemical drugs. Star-siRNA nanoparticles internalized into lung cancer cells and escaped the endo-lysosomal pathway to inhibit target gene expression in lung cancer cells in vitro. Nebulized star-siRNA nanoparticles accumulated into lungs and silenced the expression of βIII-tubulin and PLK1 in mouse lung tumors, delaying aggressive tumor growth. These results demonstrate a proof-of-concept for aerosol delivery of star-siRNA nanoparticles as a novel therapeutic strategy to inhibit lung tumor growth.
Delivering nitric oxide with nanoparticles
Publisher: Elsevier BV
Date: 05-2015
DOI: 10.1016/J.JCONREL.2015.02.007
Abstract: While best known for its important signalling functions in human physiology, nitric oxide is also of considerable therapeutic interest. As such, nanoparticle-based systems which enable the sustained exogenous delivery of nitric oxide have been the subject of considerable investigation in recent years. Herein we review the various nanoparticle systems that have been used to date for nitric oxide delivery, and explore the array of potential therapeutic applications that have been reported. Specifically, we discuss the modification of sol-gel based silica particles, functionalised metal/metal oxide nanoparticles, polymer-coated metal nanoparticles, dendrimers, micelles and star polymers to impart nitric oxide release capability. We also consider the various areas in which therapeutic applications are envisaged: wound healing, antimicrobial applications, cardiovascular treatments, sexual medicine and cancer treatment. Finally, we discuss possible future directions for this versatile and potentially important technology.
Macromolecular Hydrogen Sulfide Donors Trigger Spatiotemporally Confined Changes in Cell Signaling
Publisher: American Chemical Society (ACS)
Date: 23-12-2016
DOI: 10.1021/ACS.BIOMAC.5B01469
Abstract: Hydrogen sulfide (H2S) is involved in a myriad of cell signaling processes that trigger physiological events ranging from vasodilation to cell proliferation. Moreover, disturbances to H2S signaling have been associated with numerous pathologies. As such, the ability to release H2S in a cellular environment and stimulate signaling events is of considerable interest. Herein we report the synthesis of macromolecular H2S donors capable of stimulating cell signaling pathways in both the cytosol and at the cell membrane. Specifically, copolymers having pendent oligo(ethylene glycol) and benzonitrile groups were synthesized, and the benzonitrile groups were subsequently transformed into primary aryl thioamide groups via thionation using sodium hydrosulfide. These thioamide moieties could be incorporated into a hydrophilic copolymer or a block copolymer (i.e., into either the hydrophilic or hydrophobic domain). An electrochemical sensor was used to demonstrate release of H2S under simulated physiological conditions. Subsequent treatment of HEK293 cells with a macromolecular H2S donor elicited a slow and sustained increase in cytosolic ERK signaling, as monitored using a FRET-based biosensor. The macromolecular donor was also shown to induce a small, fast and sustained increase in plasma membrane-localized PKC activity immediately following addition to cells. Studies using an H2S-selective fluorescent probe in live cells confirmed release of H2S from the macromolecular donor over physiologically relevant time scales consistent with the signaling observations. Taken together, these results demonstrate that by using macromolecular H2S donors it is possible to trigger spatiotemporally confined cell signaling events. Moreover, the localized nature of the observed signaling suggests that macromolecular donor design may provide an approach for selectively stimulating certain cellular biochemical pathways.
Uptake and transcytosis of functionalized superparamagnetic iron oxide nanoparticles in an in vitro blood brain barrier model
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7BM01012E
Abstract: Phosphoryl choline grafting secured high cellular uptake and increased transcytosis of superparamagnetic iron oxide nanoparticles through a model blood brain barrier.
Synthesis, multilayer film assembly, and capsule formation of macromolecularly engineered acrylic acid and styrene sulfonate block copolymers
Publisher: American Chemical Society (ACS)
Date: 19-07-2008
DOI: 10.1021/LA8011074
Abstract: We report the use of copolymers synthesized with specific block ratios of weakly and strongly charged groups for the preparation of stable, pH-responsive multilayers. In this study, we utilized reversible addition-fragmentation chain transfer (RAFT) polymerization in the synthesis of novel pH-sensitive copolymers comprising block domains of acrylic acid (AA) and styrene sulfonate (SS) groups. The PAA x- b-SS y copolymers, containing 37%, 55%, and 73% of AA groups by mass (denoted as PAA 37- b-SS 63, PAA 55- b-SS 45, and PAA 73- b-SS 27, respectively), were utilized to perform stepwise multilayer assembly in alternation with poly(allylamine hydrochloride), PAH. The ratio of AA to SS groups, and the effect of the pH of both anionic and cationic adsorption solutions, on multilayer properties, were investigated using ellipsometry and atomic force microscopy. The presence of SS moieties in the PAA x- b-SS y copolymers, regardless of the precise composition, lead to films with a relatively consistent thickness. Exposure of these multilayers to acidic conditions postassembly revealed that these multilayers do not exhibit the characteristic large swelling that occurs with PAA/PAH films. The film stability was attributed to the presence of strongly charged SS groups. PAA x- b-SS y/PAH films were also formed on particle substrates under various adsorption conditions. Microelectrophoresis measurements revealed that the surface charge and isoelectric point of these core-shell particles are dependent on assembly pH and the proportion of AA groups in PAA x- b-SS y. These core-shell particles can be used as precursors to hollow capsules that incorporate weak polyelectrolyte functionality. The role of AA groups in determining the growth profile of these capsules was also examined. The multilayer films prepared may find applications in areas where pH-responsive films are required but large film swelling is unfavorable.
pH-Responsive Poly(acrylic acid) Core Cross-Linked Star Polymers: Morphology Transitions in Solution and Multilayer Thin Films
Publisher: American Chemical Society (ACS)
Date: 13-03-2008
DOI: 10.1021/MA7019557
Sustained endosomal release of a neurokinin-1 receptor antagonist from nanostars provides long-lasting relief of chronic pain
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.BIOMATERIALS.2022.121536
Abstract: Soft polymer nanoparticles designed to disassemble and release an antagonist of the neurokinin 1 receptor (NK
Elucidating the Influences of Size, Surface Chemistry, and Dynamic Flow on Cellular Association of Nanoparticles Made by Polymerization-Induced Self-Assembly
Publisher: Wiley
Date: 25-07-2018
Abstract: The size and surface chemistry of nanoparticles dictate their interactions with biological systems. However, it remains unclear how these key physicochemical properties affect the cellular association of nanoparticles under dynamic flow conditions encountered in human vascular networks. Here, the facile synthesis of novel fluorescent nanoparticles with tunable sizes and surface chemistries and their association with primary human umbilical vein endothelial cells (HUVECs) is reported. First, a one-pot polymerization-induced self-assembly (PISA) methodology is developed to covalently incorporate a commercially available fluorescent dye into the nanoparticle core and tune nanoparticle size and surface chemistry. To characterize cellular association under flow, HUVECs are cultured onto the surface of a synthetic microvascular network embedded in a microfluidic device (SynVivo, INC). Interestingly, increasing the size of carboxylic acid-functionalized nanoparticles leads to higher cellular association under static conditions but lower cellular association under flow conditions, whereas increasing the size of tertiary amine-decorated nanoparticles results in a higher level of cellular association, under both static and flow conditions. These findings provide new insights into the interactions between polymeric nanomaterials and endothelial cells. Altogether, this work establishes innovative methods for the facile synthesis and biological characterization of polymeric nanomaterials for various potential applications.
Trisulfide-Bearing PEG Brush Polymers Donate Hydrogen Sulfide and Ameliorate Cellular Oxidative Stress
Publisher: American Chemical Society (ACS)
Date: 19-11-2020
Synthesis of Customizable Macromolecular Conjugates as Building Blocks for Engineering Metal–Phenolic Network Capsules with Tailorable Properties
Publisher: American Chemical Society (ACS)
Date: 29-10-2021
Garlic-inspired trisulfide linkers for thiol-stimulated H2S release
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CC03820H
Abstract: Garlic-inspired cholesterol-mPEG conjugates incorporating a trisulfide linkage have the ability to cleave upon exposure to thiols with a concomitant release of H 2 S.
Transformation of RAFT Polymer End Groups into Nitric Oxide Donor Moieties: En Route to Biochemically Active Nanostructures
Publisher: American Chemical Society (ACS)
Date: 03-11-2015
Trisulfide linked cholesteryl PEG conjugate attenuates intracellular ROS and collagen-1 production in a breast cancer co-culture model
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0BM01544J
Abstract: Treatment of cancer cell-fibroblast co-cultures with H 2 S-releasing trisulfide conjugate causes restoration of ROS levels in the cancer cells and normalisation of collagen-1 expression in the fibroblasts.
Nitroxide-functional PEGylated nanostars arrest cellular oxidative stress and exhibit preferential accumulation in co-cultured breast cancer cells
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1TB00812A
Abstract: Conjugation to nanostars enhances the biological performance of TEMPO.
The application of ionizing radiation in reversible addition-fragmentation chain transfer (RAFT) polymerization: Renaissance of a key synthetic and kinetic tool
Publisher: Elsevier BV
Date: 10-2007
Rapid synthesis of ultrahigh molecular weight and low polydispersity polystyrene diblock copolymers by RAFT-mediated emulsion polymerization
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5PY00166H
Abstract: An environmentally friendly emulsion technique produces uniform nanoparticles with precise control over molecular weight and particle size.
Synthesis and in vitro properties of iron oxide nanoparticles grafted with brushed phosphorylcholine and polyethylene glycol
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5PY02024G
Abstract: A new and facile strategy for grafting IONPs by phosphonic acic terminated PC brushes has been demonstrated and characterized in vitro .
Polymerization-Induced Self-Assembly: The Effect of End Group and Initiator Concentration on Morphology of Nanoparticles Prepared via RAFT Aqueous Emulsion Polymerization
Publisher: American Chemical Society (ACS)
Date: 31-08-2017
Nitric oxide (NO) cleavable biomimetic thermoresponsive double hydrophilic diblock copolymer with tunable LCST
Publisher: American Chemical Society (ACS)
Date: 11-06-2015
Tailoring the Chain Packing in Ultrathin Polyelectrolyte Films Formed by Sequential Adsorption: Nanoscale Probing by Positron Annihilation Spectroscopy
Publisher: American Chemical Society (ACS)
Date: 21-11-2012
DOI: 10.1021/JA308716V
Abstract: Depth profiling experiments by positron annihilation spectroscopy have been used to investigate the free volume element size and concentration in films assembled using the layer-by-layer (LbL) adsorption method. Films prepared from strong polyelectrolytes, weak polyelectrolytes, hydrogen-bonding polymers, and blended polyelectrolyte multilayers have different chain packing that is reflected in the free volume characteristics. The influence of various parameters on free volume, such as number of bilayers, salt concentration, solution pH, and molecular weight, has been systematically studied. The free volume cavity diameters vary from 4 to 6 Å, and the free volume concentrations vary from (1.1-4.3) × 10(20) cm(-3), depending on the choice of assembly polymers and conditions. Films assembled from strong polyelectrolytes have fewer free volume cavities with a larger average size than films prepared from weak polyelectrolytes. Blending the weak polyanion poly(acrylic acid), PAA, with the strong polyanion poly(styrene sulfonate), PSS, to layer alternately with the polycation poly(allyamine hydrochloride), PAH, is shown to be a viable method to achieve intermediate free volume characteristics in these LbL films. An increase in salt concentration of the adsorption solutions for films prepared from strong polyelectrolytes makes these films tend toward weaker polyelectrolyte free volume characteristics. Hydrogen-bonded layered films show larger free volume element size and concentration than do their electrostatically bonded counterparts, while reducing the molecular weight of these hydrogen-bonded polymers results in slightly reduced free volume size and concentration. A study of the effect of solution pH on films prepared from weak polyelectrolytes shows that when both polyelectrolytes are substantially charged in solution (assembly pH = 7.5), the chains pack similarly to strong polyelectrolytes (i.e., lower free volume concentration), but with smaller average cavity sizes. These results give, for the first time, a clear indication of how the free volume profile develops in LbL thin films, offering numerous methods to tailor the Ångström-scale free volume properties by judicious selection of the assembly polymers and conditions. These findings can be potentially exploited to tailor the properties of thin polymer films for applications spanning membranes, sensing, and drug delivery.
Cholesterol modified self-assemblies and their application to nanomedicine
Publisher: American Chemical Society (ACS)
Date: 22-06-2015
DOI: 10.1021/ACS.BIOMAC.5B00550
Abstract: Cholesterol is a ubiquitous molecule in biological systems, and in particular plays various important roles in mammalian cellular processes. The presence of cholesterol is integral to the structure and behavior of biological membranes, and profoundly influences membrane involvement in cellular mechanisms. This review focuses on the incorporation of cholesterol into synthetic nanomaterials and assemblies, focusing on LC phase behavior, morphology/self-organization and hydrophobic interactions, all important factors in the design of nanomedicines. We highlight cholesteryl conjugates, liposomes and polymeric micelles, focusing on self-assembly capabilities, drug encapsulation and intracellular delivery. An area of considerable interest identified in this review is the use of cholesteryl-functional vectors to deliver drugs or nucleic acids. Such applications depend on the ability of the nanoparticle carrier to associate with both the cellular and endosomal membrane.
Nano-assemblies of cationic mPEG brush block copolymers with gadolinium polyoxotungstate [Gd(W5O18)2]9− form stable, high relaxivity MRI contrast agents
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8NR01544A
Abstract: Nano-assemblies of gadolinium polyoxotungstate and cationic mPEG brush block copolymer demonstrated good stability and enhanced relaxivity at physiological pH.
The Quartz Crystal Microbalance: a New Tool for the Investigation of the Bioadhesion of Diatoms to Surfaces of Differing Surface Energies
Publisher: American Chemical Society (ACS)
Date: 29-05-2008
DOI: 10.1021/LA800672H
Abstract: Diatoms are a major component of the biofoul layer found on modern low-surface-energy, 'foul release' coatings. While diatoms adhere more strongly to hydrophobic, as opposed to hydrophilic, surfaces, surprisingly little is known of the chemical composition of their adhesives. Even less is known about the underlying processes that characterize the interaction between the adhesive and a given surface, including those of differing wettability. Using the quartz crystal microbalance with dissipation monitoring (QCM-D), we examined differences in the viscoelastic properties of the extracellular adhesives produced by the marine diatoms Amphora coffeaeformis Cleve and Craspedostauros australis Cox interacting with surfaces of differing wettability 11-mercaptoundecanoic acid (MUA) that is hydrophilic and 1-undecanethiol (UDT) that is hydrophobic. While the overall delta f/delta D ratios were slightly different, the trends were the same for both diatom species, with the layer secreted upon UDT to be more viscoelastic and far more consistent over several experiments, compared to that on MUA which was less viscoelastic and demonstrated far more variability between experiments. While the nature of the parameter shifts for C. australis were the same for both surfaces, A. coffeaeformis cells settling upon UDT illustrated significant positive f and D shifts during the initial stages of cell settlement and adhesion to the surface. Further experiments revealed the parameter shifts to occur only during the initial adhesion of cells upon the pristine virgin UDT surface. The mechanism behind these parameter responses was isolated to the actin-myosin/adhesion complex (AC), using the myosin inhibitor 2,3-butanedione 2-monoxime (BDM) to remove the cells ability to 'pull' on adhesive strands emanating from the cell raphe. The observations made herein have revealed that adhesives secreted by fouling diatoms differ significantly in their interaction with surfaces depending on their wettability, as well as illustrating the unique mechanics behind the adhesion of A. coffeaeformis upon hydrophobic surfaces, a mechanism that may contribute significantly to the cells success in colonizing hydrophobic surfaces.
Multilayer Buildup and Biofouling Characteristics of PSS-b-PEG Containing Films
Publisher: American Chemical Society (ACS)
Date: 05-03-2010
DOI: 10.1021/LA100430G
Abstract: Thin films exhibiting protein resistance are of interest in erse areas, ranging from low fouling surfaces in biomedicine to marine applications. Herein, we report the preparation of low protein and cell binding multilayer thin films, formed by the alternate deposition of a block copolymer comprising polystyrene sulfonate and poly(poly(ethylene glycol) methyl ether acrylate) (PSS-b-PEG), and polyallylamine hydrochloride (PAH). Film buildup was followed by quartz crystal microgravimetry (QCM), which showed linear growth and a high degree of hydration of the PSS-b-PEG/PAH films. Protein adsorption studies with bovine serum albumin using QCM demonstrated that multilayer films of PSS/PAH with a terminal layer of PSS-b-PEG were up to 5-fold more protein resistant than PSS-terminated films. Protein binding was dependent on the ionic strength at which the terminal layer of PSS-b-PEG was adsorbed, as well as the pH of the protein solution. It was also possible to control the protein resistance of the films by coadsorption of the final layer with another component (PSS), which showed an increase in protein resistance as the proportion of PSS-b-PEG in the adsorption solution was increased. In addition, protein resistance could also be controlled by the location of a single PSS-b-PEG layer within a PSS/PAH film. Finally, the buildup of PSS-b-PEG/PAH films on colloidal particles was demonstrated. PSS-b-PEG-terminated particles exhibited a 6.5-fold enhancement in cell binding resistance compared with PSS-terminated particles. The stability of PSS-b-PEG films combined with their low protein and cell binding characteristics provide opportunities for the use of the films as low fouling coatings in devices and other surfaces requiring limited interaction with biological interfaces.
Preparation of nanoporous polyelectrolyte multilayer films via nanoparticle templating
Publisher: American Chemical Society (ACS)
Date: 21-10-2006
DOI: 10.1021/CM061626C
Reversible addition - Fragmentation chain transfer polymerization initiated with ultraviolet radiation
Publisher: American Chemical Society (ACS)
Date: 27-08-2002
DOI: 10.1021/MA0204296
Molecular weight (hydrodynamic volume) dictates the systemic pharmacokinetics and tumour disposition of PolyPEG star polymers
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.NANO.2015.08.001
Abstract: Herein we report for the first time the biological fate of poly[(oligoethylene glycol) acrylate] (POEGA) star polymers synthesised via a versatile arm-first reversible addition-fragmentation chain transfer (RAFT) polymerisation approach. The biopharmaceutical behaviour of three different molecular weight (49, 64 and 94kDa) POEGA stars was evaluated in rats and nude mice bearing human MDA MB-231 tumours after intravenous administration. The 94kDa star polymer exhibited a longer plasma exposure time than the 49kDa or 64kDa star polymer an observation attributable to differences in the rates of both polymer biodegradation and urinary excretion. Tumour biodistribution also correlated with molecular weight and was greatest for the longest circulating 94kDa star. Different patterns of liver and spleen biodistribution were observed between mice and rats for the different sized polymers. The polymers were also well-tolerated in vivo and in vitro at therapeutic concentrations. Advances in nanotechnology has enabled scientists to produce nanoparticle as drug carriers in cancer therapeutics. In this article, the authors studied the biological fate of poly[(oligoethylene glycol) acrylate] (POEGA) star polymers of different size, after intravenous injections. This would allow the subsequent comparison to other drug delivery systems for better drug delivery.
Nitric Oxide (NO) Endows Arylamine-Containing Block Copolymers with Unique Photoresponsive and Switchable LCST Properties
Publisher: American Chemical Society (ACS)
Date: 15-03-2016
Polymers with acyl-protected perthiol chain termini as convenient building blocks for doubly responsive H2S-donating nanoparticles
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7PY01484H
Abstract: H 2 S-releasing polymers with an acyl-protected perthiol chain terminus were prepared using a simple, high yielding end-group modification process.
Gadolinium-functionalized nanoparticles for application as magnetic resonance imaging contrast agents
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6PY01797E
Abstract: Polymerization-induced self-assembly (PISA) is an easily applied synthetic technique for the preparation of polymer nanoparticles with various shapes and at high concentrations.
Nanoporous polymer thin films via polyelectrolyte templating
Publisher: Wiley
Date: 05-09-2005
Overcoming Surfactant-Induced Morphology Instability of Noncrosslinked Diblock Copolymer Nano-Objects Obtained by RAFT Emulsion Polymerization
Publisher: American Chemical Society (ACS)
Date: 10-01-2018
DOI: 10.1021/ACSMACROLETT.7B00978
Abstract: RAFT emulsion polymerization techniques including polymerization-induced self-assembly (PISA) and temperature-induced morphological transformation (TIMT) are widely used to produce noncrosslinked nano-objects with various morphologies. However, the worm, vesicle and lamellar morphologies produced by these techniques typically cannot tolerate the presence of added surfactants, thus limiting their potential applications. Herein we report the surfactant tolerance of noncrosslinked worms, vesicles, and lamellae prepared by RAFT emulsion polymerizations using poly(di(ethylene glycol) ethyl ether methacrylate-
Rapid Assessment of Nanoparticle Extravasation in a Microfluidic Tumor Model
Publisher: American Chemical Society (ACS)
Date: 29-03-2019
Cu(0)-Mediated Living Radical Polymerization: A Versatile Tool for Materials Synthesis
Publisher: American Chemical Society (ACS)
Date: 30-07-2016
Controlling Nanomaterial Size and Shape for Biomedical Applications via Polymerization-Induced Self-Assembly.
Publisher: Wiley
Date: 09-08-2018
Abstract: Rapid developments in the polymerization-induced self-assembly (PISA) technique have paved the way for the environmentally friendly production of nanoparticles with tunable size and shape for a erse range of applications. In this feature article, the biomedical applications of PISA nanoparticles and the substantial progress made in controlling their size and shape are highlighted. In addition to early investigations into drug delivery, applications such as medical imaging, tissue culture, and blood cryopreservation are also described. Various parameters for controlling the morphology of PISA nanoparticles are discussed, including the degree of polymerization of the macro-CTA and core-forming polymers, the concentration of macro-CTA and core-forming monomers, the solid content of the final products, the solution pH, the thermoresponsitivity of the macro-CTA, the macro-CTA end group, and the initiator concentration. Finally, several limitations and challenges for the PISA technique that have been recently addressed, along with those that will require further efforts into the future, will be highlighted.
Facile tailoring of film morphology and release properties using layer-by-layer assembly of thermoresponsive materials
Publisher: American Chemical Society (ACS)
Date: 09-12-2004
DOI: 10.1021/LA0360310
Abstract: Layer-by-layer self-assembly was used to prepare thermoresponsive thin films of poly(N-isopropylacrylamide) (PNIPAAm) and poly(acrylic acid) (PAA) based on hydrogen bonding. The temperature of PNIPAAm adsorption was shown to significantly affect both the mass proportion of PNIPAAm in the film and the film surface morphology. When the adsorption was conducted at temperatures close to the lower critical solubility temperature of PNIPAAm, the amount of PNIPAAm in the film increased significantly (from 51 to 59%), and the total film mass increased by 30-40%. The films prepared at 30 degrees C also exhibited a lower surface roughness (1-2 nm) compared with 5-8 nm when prepared at 10 or 21 degrees C. The resulting multilayer films ([PAA/PNIPAAm]10) were capable of being reversibly loaded and unloaded with dye (Rhodamine B) by exposure to solutions at elevated temperatures. The rate of loading and release was shown to depend on both the solution temperature and film preparation temperature, leading to tunable loading/release properties.
Synthesis of star polymers by RAFT polymerization as versatile nanoparticles for biomedical applications
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/CH17391
Abstract: The precise control of polymer chain architecture has been made possible by developments in polymer synthesis and conjugation chemistry. In particular, the synthesis of polymers in which at least three linear polymeric chains (or arms) are tethered to a central core has yielded a useful category of branched architecture, so-called star polymers. Fabrication of star polymers has traditionally been achieved using either a core-first technique or an arm-first approach. Recently, the ability to couple polymeric chain precursors onto a functionalized core via highly efficient coupling chemistry has provided a powerful new methodology for star synthesis. Star syntheses can be implemented using any of the living polymerization techniques using ionic or living radical intermediates. Consequently, there are innumerable routes to fabricate star polymers with varying chemical composition and arm numbers. In comparison with their linear counterparts, star polymers have unique characteristics such as low viscosity in solution, prolonged blood circulation, and high accumulation in tumour regions. These advantages mean that, far beyond their traditional application as rheology control agents, star polymers may also be useful in the medical and pharmaceutical sciences. In this account, we discuss recent advances made in our laboratory focused on star polymer research ranging from improvements in synthesis through to novel applications of the product materials. Specifically, we examine the core-first and arm-first preparation of stars using reversible addition–fragmentation chain transfer (RAFT) polymerization. Further, we also discuss several biomedical applications of the resulting star polymers, particularly those made by the arm-first protocol. Emphasis is given to applications in the emerging area of nanomedicine, in particular to the use of star polymers for controlled delivery of chemotherapeutic agents, protein inhibitors, signalling molecules, and siRNA. Finally, we examine possible future developments for the technology and suggest the further work required to enable clinical applications of these interesting materials.
Glutathione responsive polymers and their application in drug delivery systems
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6PY01365A
Abstract: Materials which respond to biological cues are the subject of intense research interest due to their possible application in smart drug delivery vehicles.
Copolyampholytes Produced from RAFT Polymerization of Protic Ionic Liquids
Publisher: American Chemical Society (ACS)
Date: 10-11-2017
The Pharmacokinetics and Biodistribution of a 64 kDa PolyPEG Star Polymer After Subcutaneous and Pulmonary Administration to Rats
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.XPHS.2015.11.038
Abstract: PolyPEG star polymers have potential utility as cost-effective polymeric drug delivery vehicles, and as such, it is important to develop an understanding of their biopharmaceutical behavior. Moreover, although a number of studies have evaluated the utility of PolyPEG stars in vitro, investigation of these novel materials in vivo has been limited. Herein, we evaluated the pharmacokinetics of a 64 kDa tritiated PEG-based star polymer after subcutaneous and pulmonary administration in rats. After subcutaneous administration, the star polymer showed near complete bioavailability (∼80%) and a similar organ biodistribution profile to the polymer after intravenous administration. After intratracheal instillation to the lungs, the star polymer showed limited bioavailability (∼3%), and most of the administered radiolabel was recovered in lung tissue and feces after 6 d. The data reported here suggest that star polymers display similar pharmaceutical behavior to PEGylated dendrimers after subcutaneous and inhaled delivery and may therefore be used as similar, but more cost-effective drug delivery vehicles.
Facile synthesis of comb, star, and graft polymers via reversible addition–fragmentation chain transfer (RAFT) polymerization
Publisher: Wiley
Date: 15-07-2002
DOI: 10.1002/POLA.10369
Compositional engineering of polyelectrolyte blend capsules
Publisher: American Chemical Society (ACS)
Date: 14-09-2007
DOI: 10.1021/MA071372W
Stabilization of hydrogen-bonded poly(N-isopropylacrylamide) multilayers by a dual electrostatic/hydrogen bonding copolymer
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/CH05052
Abstract: Multilayer thin films were prepared based on hydrogen bonding between poly(N-isopropylacrylamide) (PNiPAAm), and poly(styrene sulfonate-co-maleic acid) (PSSMA). Since PSSMA is capable of associating with other polymers through both hydrogen bonding and electrostatic interactions, multilayer assemblies incorporating PSSMA, PNiPAAm, and intercalated poly(allylamine hydrochloride) (PAH) layers were also prepared. Intercalated PAH layers were included to improve the pH stability of the film by introducing electrostatic linkages into the assembly. Film construction was studied as a function of pH of the deposition solution and the number of inserted PAH layers. Film morphology varied significantly with incorporation of PAH into the film. It was also demonstrated that by intercalating several PAH layers within the PNiPAAm/PSSMA assembly, the pH stability of the films at pH 5.8 could be substantially improved.
Fabrication of polyelectrolyte multilayer films comprising nanoblended layers
Publisher: American Chemical Society (ACS)
Date: 04-02-2004
DOI: 10.1021/JA039830D
Abstract: Polyelectrolyte multilayer thin films were prepared via the alternate deposition of poly(allylamine hydrochloride) (PAH) and a blend of poly(acrylic acid) (PAA) and poly(styrenesulfonate) (PSS). When the pH of the blend solution was 3.5, the presence of PAA in this solution significantly increased the total film thickness. With only 10 wt % PAA in the blend adsorption solution, a large increase in film thickness was observed (92 nm cf. 18 nm). It was also demonstrated that the total amount of PSS adsorbed was enhanced by the presence of PAA in the blend solution, showing that the blend solution composition influenced that of the multilayer films. Thin films prepared with nanoblended layers also showed improved pH stability, because they exhibited reduced film rearrangement upon exposure to acidic conditions (pH = 2.5).
Living free-radical polymerization of styrene under a constant source of γ radiation
Publisher: Wiley
Date: 06-11-2002
DOI: 10.1002/POLA.10086
Polymeric filomicelles and nanoworms: two decades of synthesis and application
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6PY00639F
Abstract: This review highlights the substantial progress in the syntheses and applications of filomicelles, an emerging nanomaterial with distinct and useful properties.
Macromolecular Engineering of Thermoresponsive Metal-Phenolic Networks.
Publisher: American Chemical Society (ACS)
Date: 27-12-2022
DOI: 10.1021/JACS.1C10979
Abstract: Dynamic nanostructured materials that can react to physical and chemical stimuli have attracted interest in the biomedical and materials science fields. Metal-phenolic networks (MPNs) represent a modular class of such materials: these networks form via coordination of phenolic molecules with metal ions and can be used for surface and particle engineering. To broaden the range of accessible MPN properties, we report the fabrication of thermoresponsive MPN capsules using Fe
Layer-by-layer assembly of weak-strong copolymer polyelectrolytes: A route to morphological control of thin films
Publisher: Wiley
Date: 03-08-2007
DOI: 10.1002/POLA.22179
Application of Heterocyclic Polymers in the Ratiometric Spectrophotometric Determination of Fluoride
Publisher: American Chemical Society (ACS)
Date: 10-06-2015
DOI: 10.1021/MZ500782R
Linker chemistry dictates the delivery of a phototoxic organometallic rhenium(i) complex to human cervical cancer cells from core crosslinked star polymer nanoparticles
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8TB02464B
Abstract: Release of a photoactive Re( i ) complex from a polymer star via ketimine linkages gives improved phototoxicity.
Narrowing down chain length effects on the antibacterial action of guanylated oligomers
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3PY00203A
Abstract: Synthesis of discrete guanylated antimicrobial oligomers through reversible addition fragmentation chain transfer (RAFT) polymerization followed by flash chromatography is described.
Reproducible Access to Tunable Morphologies via the Self-Assembly of an Amphiphilic Diblock Copolymer in Water
Publisher: American Chemical Society (ACS)
Date: 19-03-2015
Next generation, sequentially assembled ultrathin films: Beyond electrostatics
Publisher: Royal Society of Chemistry (RSC)
Date: 2007
DOI: 10.1039/B610778H
Abstract: Over the last 15 years, the layer-by-layer (LbL) assembly technology has proven to be a versatile method for surface modification. This approach is likely to find widespread application because of its simplicity and versatility however, the conventional use of highly charged materials with limited responsive behaviour presents some key limitations. In this tutorial review, the formation of multilayer thin films prepared through non-electrostatic interactions is reviewed. We discuss the assembly of films via a number of different methodologies, with particular emphasis on those that provide enhanced orientational control, stimuli-responsive behaviour, and improved film stability.
Engineering Programmable DNA Particles and Capsules Using Catechol-Functionalized DNA Block Copolymers
Publisher: American Chemical Society (ACS)
Date: 03-08-2022
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