ORCID Profile
0000-0001-9690-7288
Current Organisations
Flinders University
,
University College London
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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)
Electrochemical energy storage and conversion | Macromolecular materials | Organic chemical synthesis | Materials engineering | Characterisation of Biological Macromolecules | Medicinal and Biomolecular Chemistry | Biomaterials | Biologically Active Molecules | Structural Chemistry and Spectroscopy | Polymers and plastics | Macromolecular and materials chemistry | Macromolecular and materials chemistry not elsewhere classified | Chemical engineering | Functional Materials | Materials Engineering |
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Chemical Sciences | Polymeric Materials (e.g. Paints) | Expanding Knowledge in the Medical and Health Sciences | Expanding Knowledge in the Biological Sciences
Related Links
Publications
Thin multilayer films and microcapsules containing DNA quadruplex motifs
Publisher: Wiley
Date: 23-11-2011
Abstract: The assembly of multifunctional nanostructures bearing G-quadruplex motifs broadens the prospects of using G-quadruplexes as therapeutic carriers. Herein, we report the synthesis and characterization of an oligodeoxyguanosine, G15-mer polymer conjugate. We demonstrate that G15-mer oligonucleotides grafted to a polymer chain preserve the ability to self-assemble into ordered structures. The G-quadruplex-polymer conjugates were assembled onto a surface via hybridization with 30-mer cytosine strands, C30-mer, using a layer-by-layer approach to form microcapsules. A mechanism for the sequential assembly of the multilayer films and microcapsules is presented. We further investigate the photophysical behavior of porphyrin TMPyP4 bound to multilayer-coated particles. This study shows that the multilayer films bear residual and functional quadruplex moieties that can be used to effectively bind therapeutic agents.
Synthesis of alkyne functional cyclic polymers by one-pot thiol–ene cyclization
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3PY21109F
Temperature-Induced Formation of Uniform Polymer Nanocubes Directly in Water
Publisher: American Chemical Society (ACS)
Date: 08-01-2020
DOI: 10.1021/ACS.BIOMAC.9B01637
Abstract: Conventional self-assembly methods of block copolymers in cosolvents (i.e., usually water and organic solvents) has yet to produce a pure and monodisperse population of nanocubes. The requirement to assemble a nanocube is for the second block to have a high molecular weight. However, such high molecular weight block copolymers usually result in the formation of kinetically trapped nanostructures even with the addition of organic cosolvents. Here, we demonstrate the rapid production of well-defined polymer nanocubes directly in water by utilizing the thermoresponsive nature of the second block (with 263 monomer units), in which the block copolymer was fully water-soluble below its lower critical solution temperature (LCST) and would produce a pure population of nanocubes when heated above this temperature. Incorporating a pH-responsive monomer in the second block allowed us to control the size of the nanocubes in water with pH and the LCST of the block copolymer. We then used the temperature and pH responsiveness to create an adaptive system that changes morphology when using a unique fuel. This fuel (H
Molecular-level anchoring of polymer cathodes on carbon nanotubes towards rapid-rate and long-cycle sodium-ion storage
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8QM00163D
Abstract: A non-covalent functionalized radical polymer anchored on CNTs through π–π interactions with remarkable sodium-ion battery performance as a novel cathode.
Enhancing the peroxidase-mimicking activity of hemin by covalent immobilization in polymer nanogels
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0PY01465F
Abstract: A polymeric nanozyme that can closely mimic peroxidase is presented. The coordination between pendant hemins and primary amines together with the synergistic interactions between substrates and nanogels contribute to the enhanced catalytic activity.
Self-Catalyzed Degradation of Linear Cationic Poly(2-dimethylaminoethyl acrylate) in Water
Publisher: American Chemical Society (ACS)
Date: 16-04-2011
DOI: 10.1021/BM200219E
Abstract: We report the synthesis of a low cytotoxic polycation that maintains its cationic strength for well over a few hours then degrades into a benign polymer with nontoxic byproducts. Well-defined poly(2-dimethylaminoethyl acrylate) (PDMAEA) of five different molecular weights prepared using reversible addition-fragmentation chain transfer (RAFT) "living" radical polymerization degrades slowly over 200 h (∼8 days). As this degradation is independent of both the polymer molecular weight and solution pH, it is consistent with a self-catalyzed hydrolysis process without the need for an internal or external degradation trigger. In addition, the polymer shows little or no cytotoxicity to HeLa cells for the molecular weights of 5600 and below, even at very high polymer concentrations (equivalent to a nitrogen hosphorus ratio of 200). Therefore, at sufficiently low molecular weights this polymer has the essential attributes (i.e., ability to autodegradable and low toxicity) for a delivery carrier suitable for DNA or siRNA.
Influence of Constraints within a Cyclic Polymer on Solution Properties
Publisher: American Chemical Society (ACS)
Date: 18-01-2018
DOI: 10.1021/ACS.BIOMAC.7B01690
Abstract: Cyclic polymers with internal constraints provide new insight into polymer properties in solution and bulk and can serve as a model system to explain the stability and mobility of cyclic biomacromolecules. The model system used in this work consisted of cyclic polystyrene structures, all with a nearly identical molecular weight, designed with 0-3 constraints located at strategic sites within the cyclic polymer, with either 4 or 6 branch points. The total number of branch points (or arms) within the cyclic ranged from 0 to 18. Molecular dynamic (MD) simulations showed that as the number of arms increased within the cyclic structure, the radius of gyration and the hydrodynamic radius generally decreased, suggesting the greater number of constraints resulted in a more compact polymer chain. The simulations further showed that the excluded volume was much greater for the cyclics compared to a linear polymer at the same molecular weight. The spirocyclic, a structure consisting of three rings joined in series, showed significant excluded volume effects in agreement with experimental data the reason for which is unclear at this stage. Interestingly, under a size exclusion chromatography flow, the radius of hydration for all the cyclic structures increased compared with the DLS data, and could be explained from the greater swelling of the rings perpendicular to the flow found from previous simulations on rings. This data suggests that the greater compactness, greater excluded volume and structural rearrangements under flow of constrained cyclic polymers could be used to provide a physical basis for understanding greater stability and activity of cyclic biological macromolecules.
Polyethylenimine Expanded Graphite Oxide Enables High Sulfur Loading and Long-Term Stability of Lithium–Sulfur Batteries
Publisher: Wiley
Date: 25-01-2019
Abstract: To realize practical lithium-sulfur batteries (LSBs) with long cycling life, designing cathode hosts with a high specific surface area (SSA) is recognized as an efficient way to trap the soluble polysulfides. However, it is also blamed for diminishing the volumetric energy density and being susceptible to side reactions. Herein, polyethylenimine intercalated graphite oxide (PEI-GO) with a low SSA of 4.6 m
Brush-like Polymer Prodrug with Aggregation-Induced Emission Features for Precise Intracellular Drug Tracking
Publisher: MDPI AG
Date: 29-05-2022
DOI: 10.3390/BIOS12060373
Abstract: In this study, a brush-like polymer with aggregation-induced emission (AIE) features was synthesized for drug delivery and intracellular drug tracking. The polymer consisting of tetraphenylethene (TPE) chain-end as well as oligo-poly (ethylene glycol) (PEG) and hydrazine functionalities was successfully synthesized through copper (0)-mediated reversible-deactivation radical polymerization (Cu0-mediated RDRP). Anticancer drug doxorubicin (DOX) was conjugated to the polymer and formed a prodrug named TPE-PEGA-Hyd-DOX, which contains 11% DOX. The hydrazone between DOX and polymer backbone is a pH-sensitive linkage that can control the release of DOX in slightly acidic conditions, which can precisely control the DOX release rate. The drug release of 10% after 96 h in normal cell environments compared with about 40% after 24 h in cancer cell environments confirmed the influence of the hydrazone bond. The ratiometric design of fluorescent intensities with peaks at 410 nm (emission due to AIE feature of TPE) and 600 nm (emission due to ACQ feature of DOX) provides an excellent opportunity for this product as a precise intracellular drug tracker. Cancer cells confocal microscopy showed negligible DOX solution uptake, but an intense green emission originated from prodrug uptake. Moreover, a severe red emission in the DOX channel confirmed a promising level of drug release from the prodrug in the cytoplasm. The merged images of cancer cells confirmed the high performance of the TPE-PEGA-Hyd-DOX compound in the viewpoints of cellular uptake and drug release. This polymer prodrug successfully demonstrates low cytotoxicity in healthy cells and high performance in killing cancer cells.
Genetic Schizophrenia Risk Variants Jointly Modulate Total Brain and White Matter Volume
Publisher: Elsevier BV
Date: 03-2013
Electrochemical Synthesis of Poly(trisulfides)
Publisher: American Chemical Society (ACS)
Date: 17-05-2023
DOI: 10.1021/JACS.3C03239
Processes for coating surfaces with a copolymer made from sulfur and dicyclopentadiene
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1PY01416A
Abstract: A copolymer made from sulfur and dicyclopentadiene was useful as a mercury sorbent, and also as a protective and repairable coating.
Kinetic Simulations of RAFT-Mediated Microemulsion Polymerizations of Styrene
Publisher: American Chemical Society
Date: 2012
UV-Cross-Linked Polymer Nanostructures with Preserved Asymmetry and Surface Functionality
Publisher: American Chemical Society (ACS)
Date: 02-09-2019
DOI: 10.1021/ACS.BIOMAC.9B01088
Abstract: Polymer nanostructures can be designed with tailored properties and functions by varying their shape, chemical compositions, and surface functionality. The poor stability of these soft materials in solvent other than water can be overcome by introducing cross-links. However, cross-linking complex morphologies remains a challenge. Here, by using the temperature-directed morphology transformation method, we show that the symmetric (nanoworm) and asymmetric (tadpole) nanostructure cores can be UV-cross-linked through the coupling of styrene and
Reversible polymer nanostructures by regulating SDS/PNIPAM binding
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2PY20628E
Modulating Two Copper(I)-Catalyzed Orthogonal “Click” Reactions for the One-Pot Synthesis of Highly Branched Polymer Architectures at 25 °C
Publisher: American Chemical Society (ACS)
Date: 25-05-2011
DOI: 10.1021/MA200649B
Self-Catalyzed Degradable Cationic Polymer for Release of DNA
Publisher: American Chemical Society (ACS)
Date: 31-08-2011
DOI: 10.1021/BM2007423
Abstract: The controlled release of siRNA or DNA complexes from cationic polymers is an important parameter design in polymer-based delivery carriers. In this work, we use the self-catalyzed degradable poly(2-dimethylaminoethyl acrylate) (PDMAEA) to strongly bind, protect, and then release oligo DNA (a mimic for siRNA) without the need for a cellular or external trigger. This self-catalyzed hydrolysis process of PDMAEA forms poly(acrylic acid) and N,N'-dimethylamino ethyl ethanol, both of which have little or no toxicity to cells, and offers the advantage of little or no toxicity to off-target cells and tissues. We found that PDMAEA makes an ideal component of a delivery carrier by protecting the oligo DNA for a sufficiently long period of time to transfect most cells (80% transfection after 4 h) and then has the capacity to release the DNA inside the cells after ~10 h. The PDMAEA formed large nanoparticle complexes with oligo DNA of ~400 nm that protected the oligo DNA from DNase in serum. The nanoparticle complexes showed no toxicity for all molecular weights at a nitrogen hosphorus (N/P) ratio of 10. Only the higher molecular weight polymers at very high N/P ratios of 200 showed significant levels of cytotoxicity. These attributes make PDMAEA a promising candidate as a component in the design of a gene delivery carrier without the concern about accumulated toxicity of nanoparticles in the human body after multiadministration, an issue that has become increasingly more important.
Polyacrylate-Based Delivery System for Self-adjuvanting Anticancer Peptide Vaccine
Publisher: American Chemical Society (ACS)
Date: 22-12-2014
DOI: 10.1021/JM501514H
Abstract: Vaccination can provide a safe alternative to chemotherapy by using the body's natural defense mechanisms to create a potent immune response against tumor cells. Peptide-based therapeutic vaccines against human papillomavirus (HPV)-related cancers are usually designed to elicit cytotoxic T cell responses by targeting the HPV-16 E7 oncoprotein. However, peptides alone lack immunogenicity, and an additional adjuvant or external delivery system is required. In this study, we developed new polymer-peptide conjugates to create an efficient self-adjuvanting system for peptide-based therapeutic vaccines. These conjugates reduced tumor growth and eradicated E7-positive TC-1 tumors in mice after a "single shot" immunization, without the help from an external adjuvant. The new conjugates had a significantly higher anticancer efficacy than the antigen formulated with a commercial adjuvant. Furthermore, the polymer-peptide conjugates were promptly taken up by antigen presenting cells, including dendritic cells and macrophages, and efficiently activated CD4(+) T-helper cells and CD8(+) cytotoxic T lymphocyte cells.
Nitroxide polymer gels for recyclable catalytic oxidation of primary alcohols to aldehydes
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0PY00624F
Abstract: A physically crosslinked nitroxide polymer gel has been synthesized and used as a recyclable catalyst to convert alcohols to aldehydes in air.
Rapid and Highly Efficient Functionalization of Polymer Bromide End-Groups by SET-NRC
Publisher: American Chemical Society (ACS)
Date: 02-03-2011
DOI: 10.1021/MA200148B
Polymer–peptide hybrids as a highly immunogenic single-dose nanovaccine
Publisher: Future Medicine Ltd
Date: 2014
DOI: 10.2217/NNM.13.7
Abstract: Aim: To explore four-arm star poly(t-butyl)acrylate (P t BA)–peptide and linear P t BA–peptide conjugates as a vaccine-delivery system against Group A Streptococcus. Materials & methods: P t BA nanoparticles bearing J14 peptide epitopes were prepared via alkyne-azide 1,3-dipolar cycloaddition ‘click’ reaction. The conjugated products were self-assembled into small or large nanoparticles. These nanoparticle vaccine candidates were evaluated in vivo and J14-specific antibody titers were assessed. Results & discussion: Mice vaccinated with the nanoparticles were able to produce J14-specific IgG antibodies without the use of an external adjuvant after a single immunization. We have demonstrated for the first time that the immune responses against self-assembled P t BA nanoparticles are stronger for the smaller sized (˜20 nm) nanoparticles compared with the larger (˜500nm) P t BA nanoparticles. Conclusion: PtBA analogs have the potential to be developed as potent carrier systems for single-dose synthetic vaccines. Original submitted 29 August 2012 Revised submitted 6 December 2012 Published online 23 April 2013
Modulating catalytic activity of polymer-based cuAAC click reactions
Publisher: Wiley
Date: 09-08-2011
DOI: 10.1002/POLA.24896
An influenza virus-inspired polymer system for the timed release of siRNA
Publisher: Springer Science and Business Media LLC
Date: 21-05-2013
DOI: 10.1038/NCOMMS2905
Abstract: Small interfering RNA silences specific genes by interfering with mRNA translation, and acts to modulate or inhibit specific biological pathways a therapy that holds great promise in the cure of many diseases. However, the naked small interfering RNA is susceptible to degradation by plasma and tissue nucleases and due to its negative charge unable to cross the cell membrane. Here we report a new polymer carrier designed to mimic the influenza virus escape mechanism from the endosome, followed by a timed release of the small interfering RNA in the cytosol through a self-catalyzed polymer degradation process. Our polymer changes to a negatively charged and non-toxic polymer after the release of small interfering RNA, presenting potential for multiple repeat doses and long-term treatment of diseases.
Pyrene-Functionalized PTMA by NRC for Greater π–π Stacking with rGO and Enhanced Electrochemical Properties
Publisher: American Chemical Society (ACS)
Date: 28-09-2017
Abstract: Nitroxide radical polymers can undergo both excellent electrochemical redox reactions and a rapid "click" coupling reaction with carbon-centered radicals (i.e., nitroxide radical coupling (NRC) reaction). In this work, we report a strategy to functionalize poly(2,2,6,6,-tetramethylpiperidinyl-1-oxyl methacrylate) (PTMA) with pyrene side groups through a rapid and near quantitative NRC reaction. This resulted in P(TMA-co-PyMA) random copolymers with near quantitative amounts of pyrene along the PTMA chain for greater π-π interaction with rGO, while the nitroxide radicals on the polymer could simultaneously be used for energy storage. These copolymers can bind with reduced graphene oxide (rGO) and form layered composites through noncovalent π-π stacking, attaining molecular-level dispersion. Electrochemical performance of the composites with different polymer contents (24, 35, and 45 wt %), tested in lithium ion batteries, indicated that the layered structures consisting of P(TMA-co-PyMA) maintained greater capacities at high C-rates. This simple and efficient strategy to synthesize pyrene-functionalized polymers will provide new opportunities to fabricate many other polymer composite electrodes for desired electrochemical performance.
Aqueous reversible addition‐fragmentation chain transfer dispersion polymerization of thermoresponsive diblock copolymer assemblies: Temperature directed morphology transformations
Publisher: Wiley
Date: 20-08-2012
DOI: 10.1002/POLA.26313
Linear and branched polyacrylates as a delivery platform for peptide-based vaccines
Publisher: Future Science Ltd
Date: 09-2016
Abstract: Aim: Peptide-based vaccines are designed to carry the minimum required antigen to trigger the desired immune responses however, they are usually poorly immunogenic and require appropriate delivery system. Results: Peptides, B-cell epitope (J14) derived from group A streptococcus M-protein and universal T-helper (PADRE) epitope, were conjugated to a variety of linear and branched polyacrylates. All produced conjugates formed submicron-sized particles and induced a high level of IgG titres in mice after subcutaneous immunization. These polymer–peptide conjugates demonstrated high opsonization capacity against group A streptococcus clinical isolates. Conclusion: We have successfully demonstrated that submicron-sized polymer–peptide conjugates were capable of inducing strong humoral immune responses after single immunization.
Functionalized large pore mesoporous silica nanoparticles for gene delivery featuring controlled release and co-delivery
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3TB21015D
Fine Tuning the Disassembly Time of Thermoresponsive Polymer Nanoparticles.
Publisher: American Chemical Society (ACS)
Date: 26-09-2013
DOI: 10.1021/BM4007858
Abstract: Timed-released disassembly of nanoparticles without a remote trigger or environmental cues is demonstrated in this work. The reversible addition-fragmentation chain transfer (RAFT) polymerization allowed the fine-tuning of the chemical composition in the diblock copolymers, in which the first block consisted of a hydrophilic monomer (DMA) and the second random block consisted of three different monomers: (a) the thermoresponsive NIPAM, (b) the self-catalyzed hydrolyzable DMAEA, and (c) the hydrophobic BA. These diblock copolymers were solubilized in water below the lower critical solution temperature (LCST) of the thermoresponsive second block, and heated to 37 °C (i.e., >LCST) to form small micelle nanoparticles with a narrow particle size distribution. As DMAEA hydrolyzed to acrylic acid groups, the LCST of the diblock increased, and the time at the start of micelle disassembly (t(start)) corresponded to the point where the LCST was equal to the solution temperature (i.e., 37 °C). The high water content in the PNIPAM core allowed an even degradation of the core over time. The copolymer composition allowed fine control over t(start), as this time was linearly dependent upon the BA units in the second block. These nanoparticles could also be designed to be stable (i.e., not disassemble) over a wide pH range or disassemble below a pH of 7.3. Additionally, the time from the start of disassembly to full unimer formation (t(degrade)) could be controlled by the amount of DMAEA units in the second block. A longer t(degrade) (~5.5 h) was found when the number of DMAEA units was 42 compared to t(degrade) of 1.1 h for 25 units. The nanoparticles designed in this work, through fine control of the polymer chemical composition, have the potential for drug delivery purposes for timed-release of drugs and prodrugs and other wide-ranging applications where timed-release would be beneficial.
Synthesis of well‐defined, brush‐type, amphiphilic [poly(styrene‐co‐2‐hydroxyethyl methacrylate)‐graft‐poly(ε‐caprolactone)]‐b‐poly(ethylene oxide)‐b‐[poly(styrene‐co
Publisher: Wiley
Date: 20-06-2006
DOI: 10.1002/POLA.21549
Multicarboxylic aromatic acid core initiator for the synthesis of star‐shaped poly(ϵ‐caprolactone) with carboxyl end groups
Publisher: Wiley
Date: 27-03-2006
DOI: 10.1002/APP.23234
Polymer nanocarrier system for endosome escape and timed release of siRNA with complete gene silencing and cell death in cancer cells
Publisher: American Chemical Society (ACS)
Date: 04-09-2021
DOI: 10.1021/BM401139E
Abstract: An influenza virus-inspired polymer mimic nanocarrier was used to deliver siRNA for specific and near complete gene knockdown of an osteoscarcom cell line (U-2SO). The polymer was synthesized by single-electron transfer living radical polymerization (SET-LRP) at room temperature to avoid complexities of transfer to monomer or polymer. It was the only LRP method that allowed good block copolymer formation with a narrow molecular weight distribution. At nitrogen to phosphorus (N/P) ratios of equal to or greater than 20 (greater than a polymer concentration of 13.8 μg/mL) with polo-like kinase 1 (PLK1) siRNA gave specific and near complete (>98%) cell death. The polymer further degrades to a benign polymer that showed no toxicity even at polymer concentrations of 200 μg/mL (or N/P ratio of 300), suggesting that our polymer nanocarrier can be used as a very effective siRNA delivery system and in a multiple dose administration. This work demonstrates that with a well-designed delivery device, siRNA can specifically kill cells without the inclusion of an additional clinically used highly toxic cochemotherapeutic agent. Our work also showed that this excellent delivery is sensitive for the study of off-target knockdown of siRNA.
Analysis of cyclic polymer purity by size exclusion chromatography: a model system
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0PY01277G
Abstract: Because cyclic polymers have intriguing physical properties, considerable synthetic strategies have been developed to create a wide variety of cyclic architectures.
Cyclic polymers: Methods and strategies
Publisher: Wiley
Date: 28-02-2012
DOI: 10.1002/POLA.25999
The controlled growth of conjugated polymer-quantum dot nanocomposites via a unimolecular templating strategy
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0CC06498J
Abstract: We extend the abilities of reversible deactivation radical polymerization to control the chain length and dispersity of polymers for control of the size, distribution, and functionality of organic–inorganic hybrid nanoparticles.
Uniform Symmetric and Asymmetric Polymer Nanostructures via Directed Chain Organization
Publisher: American Chemical Society (ACS)
Date: 14-11-2018
DOI: 10.1021/ACS.BIOMAC.8B01558
Abstract: Polymer nanostructures can be designed with specific properties and functions, such as controlled shape, size, chemical composition, and adaptive ability to change shape or size in response to environmental cues. Precise control to organize polymer chains into uniform nonspherical symmetric and asymmetric nanostructures and at scale remains a synthetic challenge. Here, by using the temperature-directed morphology transformation (TDMT) method we show through a systematic organization of polymer chains the synthesis of well-defined asymmetric (i.e., tadpole) and symmetric (i.e., worm) nanostructures in water at high polymer concentrations. This method further allowed the production of tadpoles with controlled and uniform tail lengths, ranging from 200 to 800 nm. The organization of chains could be driven by environmental conditions to produce adaptive nanostructure systems.
Nanofibrillar thermoreversible micellar microgels
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2SM27796D
Precise grafting of macrocyclics and dendrons to a linear polymer chain
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6PY01317A
Abstract: Sequential growth of multifunctional telechelic polymer chains allowing grafting of polymeric dendrons and cyclics equally spaced along the backbone.
Synthesis of (ABCB)n type ternary amphiphilic multiblock copolymer via poly(ethylene oxide) macro-chain transfer agent
Publisher: Elsevier BV
Date: 10-2006
Effect of heteroatom and functionality substitution on the oxidation potential of cyclic nitroxide radicals: role of electrostatics in electrochemistry
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7CP07444A
Abstract: Electrostatic effects on electrochemical oxidation potentials of heteroatomic and functional substituted nitroxides were studied both experimentally and computationally.
One-Pot Conversion of RAFT-Generated Multifunctional Block Copolymers of HPMA to Doxorubicin Conjugated Acid- and Reductant-Sensitive Crosslinked Micelles
Publisher: American Chemical Society (ACS)
Date: 10-10-2008
DOI: 10.1021/BM800657E
Abstract: N-(2-Hydroxypropyl)methacrylamide (HPMA) containing polymers that are widely used as anticancer drug carriers. We have synthesized new hiphilic block copolymers of HPMA with a functional monomer 2-(2-pyridyldisulfide)ethylmethacrylate (PDSM) via reversible addition-fragmentation chain transfer (RAFT) polymerization. In a one-pot reaction, the versatility of PDS groups on poly(PDSM)- b-poly(HPMA) was used to conjugate an anticancer drug, doxorubicin (DOX), and also simultaneously crosslink the micellar assemblies via acid-cleavable hydrazone bonds and reducible disulfide bonds. DOX-conjugated crosslinked micelles with an average diameter of approximately 60 nm were observed to be formed in aqueous medium. Disintegration of the micelles into unimers in the presence of a disulfide reducing agent confirmed the crosslinking via disulfide bonds. While the release of DOX from the crosslinked micelles at pH 5.0 was faster compared to the release at pH 7.4, a high proportion of released DOX was found to retain the original active structure. Overall results demonstrate the simplicity and the versatility of the poly(PDSM)- b-poly(HPMA) system, which are potentially important in the design of new generation of polymer therapeutics.
Reform in medical and health sciences educational system: a Delphi study of faculty members' views at Shiraz University of Medical Sciences
Publisher: World Health Organization Regional Office for the Eastern Mediterranean (WHO/EMRO)
Date: 03-2014
Conjugated Nitroxide Radical Polymers: Synthesis and Application in Flexible Energy Storage Devices
Publisher: American Chemical Society (ACS)
Date: 28-01-2019
Abstract: The synthesis and electrochemical behavior of nitroxide radical conjugated polymers (NCPs) have long been an intriguing topic in redox polymer-based energy storage. However, common (electro)chemical oxidation polymerization methods have proved difficult in the synthesis of well-defined NCPs, and many of these polymers have been difficult to process into thin films. In addition to these drawbacks and coupled with the complex charge-transfer and storage mechanisms, the use of NCPs as electrodes has been significantly limited. The aim of this work is to provide mechanistic insights into this complex charge-transfer and storage process using a new and well-defined NCP synthesized using an ultrafast cyclopolymerization with the Grubbs 3rd generation catalyst. The monomer, consisting of a 1,6-heptadiyne group and a TEMPO (i.e. 2,2,6,6-tetramethylpiperidine-1-oxy) radical, through the cyclopolymerization produced a well-defined NCP with a five-membered ring-containing polyene backbone. This polymer demonstrated excellent film formation properties, allowing the study of their thin-film electrochemical behavior. We found that the electrochemical oxidation of the conjugated backbone and its internal charge transfer to the nitroxide radicals were strongly affected by the applied potential window, current densities, and cycle numbers. Using these new insights, we successfully utilized our NCPs in a flexible energy storage device by fabricating high-performance NCP-coated carbon cloth-based flexible electrodes.
Construction of a 3-Miktoarm Star from Cyclic Polymers
Publisher: American Chemical Society (ACS)
Date: 08-06-2012
DOI: 10.1021/MZ300259V
Abstract: Cyclic polymers have intriguing physical properties, including those found in biological membranes for greater temperature, salt and acid stability. Although, many unique and complex synthetic cyclic structures have been prepared, there are no reports of ABC miktoarm stars constructed of three cyclic polymers with very different chemical compositions. We report such a structure in one pot at 25 °C by modulating the copper catalyst activity using combinations of solvents and ligands.
Functional Disulfide-Stabilized Polymer−Protein Particles
Publisher: American Chemical Society (ACS)
Date: 30-09-2009
DOI: 10.1021/BM900817A
Abstract: Polymer-protein hybrid particles (PPHPs) have a significant potential in drug delivery, diagnosis, and biomedical imaging applications. Herein, we describe a simple route to disulfide cross-linked, poly(ethylene glycol)-streptavidin hybrid particles with tunable diameters. These particles have great versatility and potential for a number of reasons. First, they possess free biotin binding sites on their streptavidin (SAv) coated surface, enabling the conjugation of any biotinylated-molecule such as biotinylated antibodies. Second, core-stabilization can easily be controlled using reversible disulfide cross-links, and third, thiol- and ene-reactive functionalities in the core are available for the conjugation of drugs and labels. In detail, micelles having a biotinylated poly(ethylene glycol) corona and a disulfide cross-linked, reactive core were formed using alpha-biotin PEG-b-poly(pyridyldisulfide ethylmethacrylate) block copolymers synthesized via RAFT polymerization. Functionalization of the micelle core was performed in a one-pot reaction concurrent with the micellization and cross-linking processes by using a thiol-reactive model compound (a maleimide derivative of a green fluorophore). The resultant micelles displayed spherical morphology with a diameter of 54 +/- 4 nm. Biotin functionality was largely exposed on the micelle corona (75 mol % availability), as determined by a streptavidin/HABA assay. The micelles were subsequently decorated with (red fluorophore-labeled) streptavidin (SAv) through the accessible biotins on the surface, yielding SAv-linked micelle aggregates with tunable dimensions (in the range between 350 nm and 2 microm), as determined by transmission electron microscopy. Fluorescent-labels on the particles were monitored using confocal microscopy, revealing that the SAv coats the periphery of the PPHPs.
An approach to biodegradable star polymeric architectures using disulfide coupling
Publisher: Royal Society of Chemistry (RSC)
Date: 2008
DOI: 10.1039/B817037A
Abstract: The straightforward synthesis of biodegradable star polymers via both in situ polymerization from a trifunctional RAFT agent and post-polymerization conjugation of pyridyldisulfide-ended linear polymers to a trithiol precursor is described.
Schizophrenia genetic variants are not associated with intelligence
Publisher: Cambridge University Press (CUP)
Date: 15-02-2013
DOI: 10.1017/S0033291713000196
Abstract: Schizophrenia is associated with lower pre-morbid intelligence (IQ) in addition to (pre-morbid) cognitive decline. Both schizophrenia and IQ are highly heritable traits. Therefore, we hypothesized that genetic variants associated with schizophrenia, including copy number variants (CNVs) and a polygenic schizophrenia (risk) score (PSS), may influence intelligence. IQ was estimated with the Wechsler Adult Intelligence Scale (WAIS). CNVs were determined from single nucleotide polymorphism (SNP) data using the QuantiSNP and PennCNV algorithms. For the PSS, odds ratios for genome-wide SNP data were calculated in a s le collected by the Psychiatric Genome-Wide Association Study (GWAS) Consortium (8690 schizophrenia patients and 11 831 controls). These were used to calculate in idual PSSs in our independent s le of 350 schizophrenia patients and 322 healthy controls. Although significantly more genes were disrupted by deletions in schizophrenia patients compared to controls ( p = 0.009), there was no effect of CNV measures on IQ. The PSS was associated with disease status ( R 2 = 0.055, p = 2.1 × 10 −7 ) and with IQ in the entire s le ( R 2 = 0.018, p = 0.0008) but the effect on IQ disappeared after correction for disease status. Our data suggest that rare and common schizophrenia-associated variants do not explain the variation in IQ in healthy subjects or in schizophrenia patients. Thus, reductions in IQ in schizophrenia patients may be secondary to other processes related to schizophrenia risk.
Thermoresponsive Worms for Expansion and Release of Human Embryonic Stem Cells
Publisher: American Chemical Society (ACS)
Date: 26-02-2014
DOI: 10.1021/BM401702H
Abstract: The development of robust suspension cultures of human embryonic stem cells (hESCs) without the use of cell membrane disrupting enzymes or inhibitors is critical for future clinical applications in regenerative medicine. We have achieved this by using long, flexible, and thermoresponsive polymer worms decorated with a recombinant vitronectin subdomain that bridge hESCs, aiding in hESC's natural ability to form embryoid bodies (EBs) and satisfying their inherent requirement for cell-cell and cell-extracellular matrix contact. When the EBs reached an optimal upper size where cytokine and nutrient penetration becomes limiting, these long and flexible polymer worms facilitated EB breakdown via a temperature shift from 37 to 25 °C. The thermoresponsive nature of the worms enabled a cyclical dissociation and propagation of the cells. Repeating the process for three cycles (over eighteen days) provided a >30-fold expansion in cell number while maintaining pluripotency, thereby providing a simple, nondestructive process for the 3D expansion of hESC.
Electrochemical Synthesis of Gold‐N‐Heterocyclic Carbene Complexes**
Publisher: Wiley
Date: 24-10-2023
Sequence Control of Macromers via Iterative Sequential and Exponential Growth
Publisher: American Chemical Society (ACS)
Date: 19-12-2016
DOI: 10.1021/JACS.6B10869
Abstract: A general strategy through the use of direct azidation of alcohols allowed the sequence control of macromers via both the iterative sequential growth and iterative exponential growth methods. The chemistry was highly efficient in building polymers from a sequence of compositionally different macromers tethered together in close proximity. Using the DPPA/DBU method for near quantitative azidation of the benzyl alcohol moiety, sequence controlled polymers were made via a direct and one-step procedure for CuAAC activation. With four different macromers, spherical miktoarm star-like polymers of 50 000 molecular weight were prepared with a low dispersity, and the polymer coil size depended on the type of added macromer. Polymers made via the iterative methods opens the way for the design of advanced materials with predictable properties.
RAFT polymerization and thiol-ene modification of 2-vinyloxyethyl methacrylate: Towards functional branched polymers
Publisher: Elsevier BV
Date: 11-2009
Ionic Effect on Electrochemical Behavior of Water-Soluble Radical Polyelectrolytes
Publisher: American Chemical Society (ACS)
Date: 07-2022
Modelling mercury sorption of a polysulfide coating made from sulfur and limonene
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2CP01903E
Abstract: Detailed kinetic modelling of mercury uptake for a sulfur-limonene copolymer was undertaken. The effect of pH and salt concentration on mercury sorption, as well as selectivity, was assessed for the first time for this mercury-binding polymer.
Intracellular Trafficking Pathways for Nuclear Delivery of Plasmid DNA Complexed with Highly Efficient Endosome Escape Polymers
Publisher: American Chemical Society (ACS)
Date: 03-09-2014
DOI: 10.1021/BM5008376
Abstract: Understanding the pathways for nuclear entry could see vast improvements in polymer design for the delivery of genetic materials to cells. Here, we use a novel diblock copolymer complexed with plasmid DNA (pDNA) to determine both its cellular entry and nuclear pathways. The diblock copolymer (A-C3) is specifically designed to bind and protect pDNA, release it at a specific time, but more importantly, rapidly escape the endosome. The copolymer was taken up by HEK293 cells preferentially via the clathrin-mediated endocytosis (CME) pathway, and the pDNA entered the nucleus to produce high gene expression levels in all cells after 48 h, a similar observation to the commercially available polymer transfection agent, PEI Max. This demonstrates that the polymers must first escape the endosome and then mediate transport of pDNA to the nucleus for occurrence of gene expression. The amount of pDNA within the nucleus was found to be higher for our A-C3 polymer than PEI Max, with our polymer delivering 7 times more pDNA than PEI Max after 24 h. We further found that entry into the nucleus was primarily through the small nuclear pores and did not occur during mitosis when the nuclear envelope becomes compromised. The observation that the polymers are also found in the nucleus supports the hypothesis that the large pDNA olymer complex (size ~200 nm) must dissociate prior to nucleus entry and that cationic and hydrophobic monomer units on the polymer may facilitate active transport of the pDNA through the nuclear pore.
Synthesis of Versatile Thiol-Reactive Polymer Scaffolds via RAFT Polymerization
Publisher: American Chemical Society (ACS)
Date: 20-06-2008
DOI: 10.1021/BM800197V
Abstract: Well-defined polymer scaffolds convertible to (multi)functional polymer structures via selective and efficient modifications potentially provide an easy, versatile, and useful approach for a wide variety of applications. Considering this, a homopolymer scaffold, poly(pyridyldisulfide ethylmethacrylate) (poly(PDSM)), having pendant groups selectively reactive with thiols, was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. Soluble polymers with controlled molecular weights and narrow PDIs were generated efficiently. The versatility of the scaffold to generate random co- and ter-polymers combining multiple functionalities with controlled-composition was shown by separate and simultaneous conjugation of different mercapto-compounds, including a tripeptide in one-step. Conversion of water-insoluble scaffold to peptide-containing water-soluble copolymers was observed to yield nanometer-size particles with narrow polydispersity. The overall results suggest that the well-defined PDSM homopolymer scaffold generated via RAFT polymerization can be a versatile building block for generation of new structures having potential for drug delivery applications via a straightforward synthetic approach.
Synthesis and self‐assembly morphologies of amphiphilic multiblock copolymers [poly(ethylene oxide)‐b‐polystyrene]n via trithiocarbonate‐embedded PEO macro‐RAFT agent
Publisher: Wiley
Date: 11-09-2006
DOI: 10.1002/POLA.21690
Polyacrylate Dendrimer Nanoparticles: A Self‐Adjuvanting Vaccine Delivery System
Publisher: Wiley
Date: 28-07-2010
Synthesis of Amphiphilic Macrocyclic Graft Copolymer Consisting of a Poly(ethylene oxide) Ring and Multi-Polystyrene Lateral Chains
Publisher: American Chemical Society (ACS)
Date: 13-07-2006
DOI: 10.1021/MA060934T
RAFT controlled synthesis of six-armed biodegradable star polymeric architectures via a ‘core-first’ methodology
Publisher: Elsevier BV
Date: 09-2009
Anthraquinone-Catalyzed TEMPO Reduction to Realize Two-Electron Energy Storage of Poly(TEMPO-methacrylate)
Publisher: American Chemical Society (ACS)
Date: 28-03-2022
Directing the pathway of orthogonal ‘click’ reactions by modulating copper-catalytic activity
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0CC05478J
Abstract: Control of the rates of orthogonal 'click' reactions in one pot allowed the design of highly branched macromolecular architectures. Construction of these architectures via a ergent, convergent or parallel sequence was modulated by the copper catalyst activity. This approach reduced the number of purification and chemical protection steps.
The impact of the molecular weight on the electrochemical properties of poly(TEMPO methacrylate)
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7PY00151G
Abstract: This work reports the synthesis of high molecular weight poly(TEMPO methacrylate) and the molecular weight influence on electrochemical properties.
Rapid, Selective, and Reversible Nitroxide Radical Coupling (NRC) Reactions at Ambient Temperature
Publisher: American Chemical Society (ACS)
Date: 10-11-2009
DOI: 10.1021/MA9014565
Genome-wide association study identifies five new schizophrenia loci
Publisher: Springer Science and Business Media LLC
Date: 18-09-2011
DOI: 10.1038/NG.940
Nitroxide radical polymers for emerging plastic energy storage and organic electronics: fundamentals, materials, and applications
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0MH01391A
Abstract: We review the electrochemical theory, material design, and device fabrication for nitroxide radical polymers in emerging plastic energy storage and organic electronics.
GRGD‐decorated three‐dimensional nanoworm hydrogels for culturing human embryonic stem cells
Publisher: Wiley
Date: 20-02-2019
DOI: 10.1002/POLA.29342
Timed-release polymers as novel transfection reagents
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4PY00176A
Abstract: Timed-release polymer with 95% gene expression, which was greater than a commercial transfection reagent.
Self-Adjuvanting Polymer–Peptide Conjugates As Therapeutic Vaccine Candidates against Cervical Cancer
Publisher: American Chemical Society (ACS)
Date: 22-07-2013
DOI: 10.1021/BM400626W
Abstract: Dendrimers are structurally well-defined, synthetic polymers with sizes and physicochemical properties often resembling those of biomacromolecules (e.g., proteins). As a result, they are promising candidates for peptide-based vaccine delivery platforms. Herein, we established a synthetic pathway to conjugate a human papillomavirus (HPV) E7 protein-derived peptide antigen to a star-polymer to create a macromolecular vaccine candidate to treat HPV-related cancers. These conjugates were able to reduce tumor growth and eradicate E7-expressing TC-1 tumors in mice after a single immunization, without the help of any external adjuvant.
Peptidomimetic Star Polymers for Targeting Biological Ion Channels
Publisher: Public Library of Science (PLoS)
Date: 23-03-2016
Timed-Release Polymer Nanoparticles
Publisher: American Chemical Society (ACS)
Date: 16-01-2013
DOI: 10.1021/BM301721K
Abstract: Triggered-release of encapsulated therapeutics from nanoparticles without remote or environmental triggers was demonstrated in this work. Disassembly of the polymer nanoparticles to unimers at precise times allowed the controlled release of oligo DNA. The polymers used in this study consisted of a hydrophilic block for stabilization and second thermoresponsive block for self-assembly and disassembly. At temperatures below the second block's LCST (i.e., below 37 °C for in vitro assays), the diblock copolymer was fully water-soluble, and when heated to 37 °C, the polymer self-assembled into a narrow size distribution of nanoparticles with an average diameter of approximately 25 nm. The thermoresponsive nature of the second block could be manipulated in situ by the self-catalyzed degradation of cationic 2-(dimethylamino)ethyl acrylate (DMAEA) units to negatively charged acrylic acid groups and when the amount of acid groups was sufficiently high to increase the LCST of the second block above 37 °C. The disassembly of the nanoparticles could be controlled from 10 to 70 h. The use of these nanoparticles as a combined therapy, in which one or more agents can be released in a predetermined way, has the potential to improve the personal point of care treatment of patients.
Stable organic radical polymers: synthesis and applications
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6PY00996D
Abstract: We present an overview of the synthetic strategies and methodologies for stable organic radical polymers, and summarise their applications in erse areas.
CNVs conferring risk of autism or schizophrenia affect cognition in controls
Publisher: Springer Science and Business Media LLC
Date: 18-12-2013
DOI: 10.1038/NATURE12818
Abstract: In a small fraction of patients with schizophrenia or autism, alleles of copy-number variants (CNVs) in their genomes are probably the strongest factors contributing to the pathogenesis of the disease. These CNVs may provide an entry point for investigations into the mechanisms of brain function and dysfunction alike. They are not fully penetrant and offer an opportunity to study their effects separate from that of manifest disease. Here we show in an Icelandic s le that a few of the CNVs clearly alter fecundity (measured as the number of children by age 45). Furthermore, we use various tests of cognitive function to demonstrate that control subjects carrying the CNVs perform at a level that is between that of schizophrenia patients and population controls. The CNVs do not all affect the same cognitive domains, hence the cognitive deficits that drive or accompany the pathogenesis vary from one CNV to another. Controls carrying the chromosome 15q11.2 deletion between breakpoints 1 and 2 (15q11.2(BP1-BP2) deletion) have a history of dyslexia and dyscalculia, even after adjusting for IQ in the analysis, and the CNV only confers modest effects on other cognitive traits. The 15q11.2(BP1-BP2) deletion affects brain structure in a pattern consistent with both that observed during first-episode psychosis in schizophrenia and that of structural correlates in dyslexia.
Temperature-Directed Self-Assembly: from Tadpole to Multi-Arm Polymer Nanostructures Directly in Water
Publisher: American Chemical Society (ACS)
Date: 12-09-2017
Interaction of Human Arylamine N-Acetyltransferase 1 with Different Nanomaterials
Publisher: American Society for Pharmacology & Experimental Therapeutics (ASPET)
Date: 17-12-2013
Abstract: Humans are exposed to nanoparticles in the environment as well as those in nanomaterials developed for biomedical applications. However, the safety and biologic effects of many nanoparticles remain to be elucidated. Over the past decade, our understanding of the interaction of proteins with various nanomaterials has grown. The protein corona can determine not only how nanoparticles interact with cells but also their biologic effects and toxicity. In this study, we describe the effects that several different classes of nanoparticles exert on the enzymatic activity of the cytosolic protein human arylamine N-acetyltransferase 1 (NAT1), a drug-metabolizing enzyme widely distributed in the body that is also responsible for the activation and detoxification of known carcinogens. We investigated three metal oxides (zinc oxide, titanium dioxide, and silicon dioxide), two synthetic clay nanoparticles (layered double hydroxide and layered silicate nanoparticles), and a self-assembling thermo-responsive polymeric nanoparticle that differ in size and surface characteristics. We found that the different nanoparticles induced very different responses, ranging from inhibition to marked enhancement of enzyme activity. The layered silicates did not directly inactivate NAT1, but was found to enhance substrate-dependent inhibition. These differing effects demonstrate the multiplicity of nanoparticle-protein interactions and suggest that enzyme activity may be compromised in organs exposed to nanoparticles, such as the lungs or reticulo-endothelial system.
Programmable Disassembly of Polymer Nanoparticles through Surfactant Interactions
Publisher: American Chemical Society (ACS)
Date: 24-06-2019
An EGFR targeting nanoparticle self assembled from a thermoresponsive polymer
Publisher: Wiley
Date: 11-09-2014
DOI: 10.1002/JCTB.4509
One-Pot Orthogonal Copper-Catalyzed Synthesis and Self-Assembly of l -Lysine-Decorated Polymeric Dendrimers
Publisher: American Chemical Society (ACS)
Date: 02-03-2015
A comparative study of the SET-LRP of oligo(ethylene oxide) methyl ether acrylate in DMSO and in H2O
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2PY20782F
Developing a green-building design approach by selective use of systems and techniques
Publisher: Informa UK Limited
Date: 13-10-2015
Printable Hydrogel Arrays for Portable and High-Throughput Shear-Mediated Assays
Publisher: American Chemical Society (ACS)
Date: 20-06-2023
Runs of Homozygosity Implicate Autozygosity as a Schizophrenia Risk Factor
Publisher: Public Library of Science (PLoS)
Date: 12-04-2012
Densely Packed Multicyclic Polymers
Publisher: American Chemical Society (ACS)
Date: 11-09-2017
Biodegradable Star Polymers Functionalized With β-Cyclodextrin Inclusion Complexes
Publisher: American Chemical Society (ACS)
Date: 07-08-2009
DOI: 10.1021/BM900646G
Abstract: Three-armed biodegradable star polymers made from polystyrene (polySt) and poly (polyethylene glycol) acrylate (polyPEG-A) were synthesized via a "core first" methodology using a trifunctional RAFT agent, created by attaching RAFT agents to a core via their R-groups. The resultant three-armed polymeric structures were well-defined, with polydispersity indices less than 1.2. Upon aminolysis and further reaction with dithiodipyridine (DTDP), these three-armed polymers could be tailored with sulfhydryl and pyridyldisulfide (PDS) end functionalities, available for further reaction with any free-sulfhydryl group containing precursors to form disulfide linkages. Nuclear magnetic resonance (NMR) confirmed that more than 98% of the polymer arms retained integral trithiocarbonate active sites after polymerization. Intradisulfide linkages between the core and the arms conferred biodegradability on the star architectures. Subsequently, the arm-termini were attached to cholesterol also via disulfide linkages. The cholesterol terminated arms were then used to form supramolecular structures via inclusion complex formation with beta-cyclodextrin (beta-CD). The star architectures were found to degrade rapidly on treatment with DL-dithiothereitol (DTT). The star polymers and supramolecular structures were characterized using gel permation chromatography (GPC), static light scattering (SLS), 2D NMR, and fluorescence spectroscopy.
Temperature-Induced Gels from Worms Made by RAFT-Mediated Emulsion Polymerization
Publisher: American Chemical Society
Date: 2015
One-Pot Synthesis of Mikto Three-Arm AB2 Stars Constructed from Linear and Macrocyclic Polymer Chains.
Publisher: American Chemical Society (ACS)
Date: 17-07-2012
DOI: 10.1021/MA301296W
Quantitative end-group functionalization of PNIPAM from aqueous SET-LRP via in situ reduction of Cu(ii ) with NaBH4
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6PY00968A
Abstract: Rapid in situ azidation and CuAAC ‘click’ reaction demonstrating very high chain-end functionality.
Conditions for multicompartment polymeric tadpoles via temperature directed self-assembly
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7PY01024A
Abstract: Conditions to form well-defined polymeric tadpole nanostructures.
Variability in Working Memory Performance Explained by Epistasis vs Polygenic Scores in theZNF804APathway
Publisher: American Medical Association (AMA)
Date: 07-2014
Glass Transition Temperature of Cyclic Stars
Publisher: American Chemical Society (ACS)
Date: 24-11-2014
DOI: 10.1021/MZ500684V
Abstract: Cyclic homo- and diblock copolymers with different topologies were synthesized using a combination of "living" radical polymerization and "click" coupling reactions. The topologies included 2- and 3-arm stars, with the arms consisting of either cyclic or linear polystyrene. In addition, a diblock consisting of a cyclic polystyrene and a cyclic poly(acrylic acid) was also made. The topologies by imposing topological constraints due to the presence of cyclic polymers and branch points had a marked influence on the glass transition temperature (
Temperature-Directed Assembly of Stacked Toroidal Nanorattles
Publisher: American Chemical Society (ACS)
Date: 19-10-2017
Effect of polymer grafting density on silica nanoparticle toxicity
Publisher: Elsevier BV
Date: 12-2012
DOI: 10.1016/J.BMC.2012.09.045
Abstract: Nanoparticles are commonly engineered with a layer of polymers on the surface used to increase their stability and biocompatibility, as well as providing multifunctional properties. Formulating the nanoparticle size and surface properties with polymers directly affects the way these nanoparticles interact with a biological system. Many previous studies have emphasized the importance of nanoparticle size and surface charge in affecting their toxicity in cells. However, the potential weakness in many of these studies is that the polymer grafting densities on nanoparticles have been disregarded during toxicity evaluation. In the current study, we hypothesized that the density of polymers on nanoparticles will affect their toxicity to cells, especially for nanoparticle cores that are toxic themselves. To address this issue, we synthesized a range of RAFT (reversible addition fragmentation chain transfer) polymers bearing different surface charges and coated them onto silica nanoparticles (SiNPs) with different grafting densities. The in vitro cytotoxicity of these SiNPs was evaluated using the MTT (thiazolyl blue tetrazolium bromide) assay with Caco-2 cells. We found that neutral (biocompatible) polymers with a high grafting density on SiNPs were effective at protecting the cells from the toxicity of the silica core. High cellular toxicity was only observed for cationic polymer-SiNPs, while all other neutral and anionic polymer-SiNPs induced limited cellular toxicity. In contrast, the toxic effects induced by low density polymer-coated SiNPs were mostly attributed to the silica core, while the polymer coatings had a limited contribution. These findings are important indicators for the future evaluation of the toxicological profile of polymer-coated nanoparticles.
Hollow Silica Nanotubes for Space-Confined Synthesis of Noble Metal Nanorods and Nanopeapods
Publisher: American Chemical Society (ACS)
Date: 07-06-2021
RAFT-mediated emulsion polymerization of styrene with a thermoresponsive MacroCTA
Publisher: Elsevier BV
Date: 12-2016
Polymeric Nanocapsule Enhances the Peroxidase-like Activity of Fe3O4 Nanozyme for Removing Organic Dyes
Publisher: MDPI AG
Date: 03-06-2022
Abstract: Peroxidase-like nanozymes are nanoscale materials that can closely mimic the activity of natural peroxidase for a range of oxidation reactions. Surface coating with polymer nanogels has been considered to prevent the aggregation of nanozymes. For a long time, the understanding of polymer coating has been largely limited to its stabilization effect on the nanozyme in aqueous media, while little is known about how polymer coating plays a role in interaction with substrates and primary oxidants to dictate the catalytic process. This work reported a facile sequential modification of Fe3O4 nanoparticles to polyacrylamide coated nanozymes, and as low as 112 mg/L s les with only 5 mg/L Fe3O4 could nearly quantitatively (99%) remove a library of organic dyes with either H2O2 or Na2S2O8 as primary oxidants. The catalytic results and molecular simulation provide both experimental and computational evidence that the hydrogen bonding interaction between the reactant and nanozymes is key for the high local concentration hence catalytic efficiency. We envision that this work, for the first time, provides some insights into the role of polymer coating in enhancing the catalytic activity of nanozyme apart from the well-known water dispersity effect.
Nitroxide radical surfactants enable electrocatalytic oxidation of fatty alcohols in water
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3GC00785E
Abstract: TEMPO-functionalized surfactants are developed for the electrocatalytic oxidation of fatty alcohols to corresponding carbonyl compounds in water with up to 93% total conversion.
Water-Borne Nanocoating for Rapid Inactivation of SARS-CoV-2 and Other Viruses
Publisher: American Chemical Society (ACS)
Date: 23-08-2021
Synthesis of a novel block copolymer poly(ethylene oxide)‐block‐poly(4‐vinylpyridine) by combination of anionic ring‐opening and controllable free‐radical polymerization
Publisher: Wiley
Date: 28-10-2002
DOI: 10.1002/POLA.10526
Multiantigenic peptide–polymer conjugates as therapeutic vaccines against cervical cancer
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.BMC.2016.07.036
Abstract: Immunotherapy is one of the most promising strategies for the treatment of cancer. Human papillomavirus (HPV) is responsible for virtually all cases of cervical cancer. The main purpose of a therapeutic HPV vaccine is to stimulate CD8(+) cytotoxic T lymphocytes (CTLs) that can eradicate HPV infected cells. HPV oncoproteins E6 and E7 are continuously expressed and are essential for maintaining the growth of HPV-associated tumor cells. We designed polymer-based multi-antigenic formulations/constructs that were comprised of the E6 and E7 peptide epitopes. We developed an N-terminus-based epitope conjugation to conjugate two unprotected peptides to poly tert-butyl acrylate. This method allowed for the incorporation of the two antigens into a polymeric dendrimer in a strictly equimolar ratio. The most effective formulations eliminated tumors in up to 50% of treated mice. Tumor recurrence was not observed up to 3months post initial challenge.
Biodistribution of PNIPAM-Coated Nanostructures Synthesized by the TDMT Method
Publisher: American Chemical Society (ACS)
Date: 30-08-2018
DOI: 10.1021/ACS.BIOMAC.8B01196
Abstract: Targeting the spleen with nanoparticles could increase the efficacy of vaccines and cancer immunotherapy, and have the potential to treat intracellular infections including leishmaniasis, trypanosome, splenic TB, AIDS, malaria, and hematological disorders. Although, nanoparticle capture in both the liver and spleen has been well documented, there are only a few ex les of specific capture in the spleen alone. It is proposed that the larger the nanoparticle size (>400 nm) the greater the specificity and capture within the spleen. Here, we synthesized five nanostructures with different shapes (ranging from spheres, worms, rods, nanorattles, and toroids) and poly( N-isopropylacrylamide), PNIPAM, surface coating using the temperature-directed morphology transformation (TDMT) method. Globular PNIPAM (i.e., water insoluble) surface coatings have been shown to significantly increase cell uptake and enhanced enzyme activity. We incorporated a globular component of PNIPAM on the nanostructure surface and examined the in vivo biodistribution of these nanostructures and accumulation in various tissues and organs in a mouse model. The in vivo biodistribution as a function of time was influenced by the shape and PNIPAM surface composition, in which organ capture and retention was the highest in the spleen. The rods (∼150 nm in length and 15 nm in width) showed the highest capture and retention of greater than 35% to the initial injection amount compared to all other nanostructures. It was found that the rods specifically targeted the cells in the red pulp region of the spleen due to the shape and PNIPAM coating of the rod. This remarkable accumulation and selectively into the spleen represents new nanoparticle design parameters to develop new splenotropic effects for vaccines and other therapeutics.
Fibronectin-conjugated thermoresponsive nanobridges generate three dimensional human pluripotent stem cell cultures for differentiation towards the neural lineages
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.SCR.2019.101441
Abstract: Production of 3-dimensional neural progenitor cultures from human pluripotent stem cells offers the potential to generate large numbers of cells. We utilised our nanobridge system to generate 3D hPSC aggregates for differentiation towards the neural lineage, and investigate the ability to passage aggregates while maintaining cells at a stem rogenitor stage. Over 38 days, aggregate cultures exhibited upregulation and maintenance of neural-associated markers and demonstrated up to 10 fold increase in cell number. Aggregates undergoing neural induction in the presence or absence of nanobridges demonstrated no differences in marker expression, proliferation or viability. However, aggregates formed without nanobridges were statistically significantly fewer and smaller by passage 3. Organoids, cultured from aggregates, and treated with retinoic acid or rock inhibitor demonstrated terminal differentiation as assessed by immunohistochemistry. These data demonstrate that nanobridge 3D hPSC can differentiate to neural stem rogenitor cells, and be maintained at this stage through serial passaging and expansion.
Lewis Acid-Induced Reversible Disproportionation of TEMPO Enables Aqueous Aluminum Radical Batteries
Publisher: American Chemical Society (ACS)
Date: 23-06-2023
DOI: 10.1021/JACS.3C04203
Self-adjuvanting polyacrylic nanoparticulate delivery system for group A streptococcus (GAS) vaccine
Publisher: Elsevier BV
Date: 04-2011
DOI: 10.1016/J.NANO.2010.10.002
Abstract: Infection with Streptococcus pyogenes, commonly known as group A Streptococcus (GAS), is responsible for acute and postinfectious complications, including rheumatic fever and rheumatic heart disease (RHD). RHD is a global health burden, and Australia's indigenous population has one of the highest incidences of RHD worldwide. A potential peptide (J14) vaccine candidate has been previously identified from the C-terminal region of the M protein. However, such peptide-based vaccine development is h ered by a lack of carriers and adjuvants suitable for humans use. We have developed a fully synthetic peptide subunit vaccine candidate based on polyacrylate dendritic polymer. Intranasal administration of this nanoparticulate construct without additional adjuvant induced J14-specific IgG, which was also capable of in vitro opsonization of GAS, highlighting the potential of self-adjuvanting polyacrylate nanoparticle-based construct as a peptide vaccine delivery platform that may afford promising opportunities for treating systemic GAS infection. Polyacrylate dendrimers offer a unique approach to a nasally administered vaccine for addressing rheumatic heart disease. This paper describes the delivery of the J14 peptide, a C-terminal derivative of M-protein in group A Streptococcus.
Preparation of the amphiphilic macro‐rings of poly(ethylene oxide) with multi‐polystyrene lateral chains and their extraction for dyes
Publisher: Wiley
Date: 11-2007
DOI: 10.1002/POLA.22333
Differences in water sorption and proton conductivity between Nafion and SPEEK
Publisher: Wiley
Date: 03-08-2011
DOI: 10.1002/POLB.22326
Complex Polymer Topologies Built from Tailored Multifunctional Cyclic Polymers
Publisher: American Chemical Society (ACS)
Date: 16-07-2014
DOI: 10.1021/MA501049N
Unravelling kinetic and mass transport effects on two-electron storage in radical polymer batteries
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1TA03449A
Abstract: Electron transfer and mass transport kinetics between two redox couples in nitroxide radical polymers was investigated. Such impact on two-electron storage in radical polymer batteries was exemplified by two macromolecular structures.
Stabilization of Polymer-Hydrogel Capsules via Thiol-Disulfide Exchange
Publisher: Wiley
Date: 11-11-2009
Synthesis of poly(ethylene oxide) with pending 2,2,6,6‐tetramethylpiperidine‐1‐oxyl groups and its further initiation of the grafting polymerization of styrene
Publisher: Wiley
Date: 28-04-2006
DOI: 10.1002/POLA.21488
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University College London
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