Trehalose-functionalized block copolymers form serum-stable micelles

2014 ◽  
Vol 5 (17) ◽  
pp. 5160-5167 ◽  
Author(s):  
Swapnil R. Tale ◽  
Ligeng Yin ◽  
Theresa M. Reineke
Keyword(s):  
Block Copolymers ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Chain Transfer Agent ◽  
Macromolecular Chain ◽  
Reversible Addition ◽  
Poly Ethylene

Well-defined amphiphilic diblock terpolymers of poly(ethylene-alt-propylene)–poly[(N,N′-dimethylacrylamide)-grad-poly(6-deoxy-6-methacrylamido trehalose)] (denoted as PEP–poly(DMA-grad-MAT) or PT) have been synthesized using a PEP macromolecular chain transfer agent by reversible addition–fragmentation chain transfer (RAFT) polymerization.

Analysis of Thiol-sensitive Core-cross-linked Polymeric Micelles Carrying Nucleoside Pendant Groups using 'On-line' Methods: Effect of Hydrophobicity on Cross-linking and Degradation

2011 ◽  
Vol 64 (6) ◽  
pp. 766 ◽  
Author(s):  
Bianca M. Blunden ◽  
Donald S. Thomas ◽  
Martina H. Stenzel
Keyword(s):  
Block Copolymers ◽  
Polymeric Micelles ◽  
Raft Polymerization ◽  
Amphiphilic Block Copolymers ◽  
Cross Linking ◽  
Copolymer Composition ◽  
Reversible Addition ◽  
On Line ◽  
Styrene Content ◽  
Poly Ethylene

Amphiphilic block copolymers were prepared via reversible–addition fragmentation chain transfer (RAFT) polymerization and their synthesis, cross-linking, and degradation were studied using on-line monitoring. The focus of this work is the systematic alteration of the hydrophobic block using copolymers based on 5′-O-methacryloyluridine (MAU) and styrene at different compositions to determine the effect of the copolymer composition on the properties of the micelle. A poly(poly(ethylene glycol) methyl ether methacrylate) (PEGMA) macroRAFT agent was chain extended with a mixture of styrene and MAU. In both systems, an increasing fraction of styrene was found to reduce the rate of polymerization, but the functionality of the RAFT system was always maintained. The amphiphilic block copolymers were dialyzed against water to generate micelles with sizes between 17 and 25 nm according to dynamic light scattering (DLS). Increasing styrene content lead to smaller micelles (determined by DLS and transmission electron microscopy) and to lower critical micelle concentrations, which was measured using surface tensiometry. The micelles were further stabilized via core-cross-linking using bis(2-methacroyloxyethyl) disulfide as crosslinker. NMR analysis revealed a faster consumption of crosslinker with higher styrene content. These stable cross-linked micelles were investigated regarding their ability to degrade in the presence of dithiothreitol as a model reductant. Increasing the styrene content resulted in a faster degradation of the cross-linked micelles into unimers.

RAFT Polymerization of Monomers with Highly Disparate Reactivities: Use of a Single RAFT Agent and the Synthesis of Poly(styrene-block-vinyl acetate)

2013 ◽  
Vol 66 (12) ◽  
pp. 1564 ◽  
Author(s):  
Lily A. Dayter ◽  
Kate A. Murphy ◽  
Devon A. Shipp
Keyword(s):  
Block Copolymers ◽  
Vinyl Acetate ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Good Control ◽  
Scanning Calorimetry ◽  
Styrene Polymerization ◽  
Reversible Addition ◽  
Raft Agent ◽  
End Group

A single reversible addition–fragmentation chain transfer (RAFT) agent, malonate N,N-diphenyldithiocarbamate (MDP-DTC) is shown to successfully mediate the polymerization of several monomers with greatly differing reactivities in radical/RAFT polymerizations, including both vinyl acetate and styrene. The chain transfer constants (Ctr) for MDP-DTC for both these monomers were evaluated; these were found to be ~2.7 in styrene and ~26 in vinyl acetate, indicating moderate control over styrene polymerization and good control of vinyl acetate polymerization. In particular, the MDP-DTC RAFT agent allowed for the synthesis of block copolymers of these two monomers without the need for protonation/deprotonation switching, as has been previously developed with N-(4-pyridinyl)-N-methyldithiocarbamate RAFT agents, or other end-group transformations. The thermal properties of the block copolymers were studied using differential scanning calorimetry, and those with sufficiently high molecular weight and styrene composition appear to undergo phase separation. Thus, MDP-DTC may be useful for the production of other block copolymers consisting of monomers with highly dissimilar reactivities.

PolyPEGylation of Protein using Semitelechelic and Mid-functional Poly(PEGMA)s synthesized by RAFT polymerization

2011 ◽  
Vol 64 (12) ◽  
pp. 1602 ◽  
Author(s):  
Yingkai Liu ◽  
Mei Li ◽  
Dengxu Wang ◽  
Jinshui Yao ◽  
Jianxing Shen ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Polymer Chains ◽  
High Yield ◽  
Protein Surface ◽  
Molecular Weights ◽  
Pharmaceutical Protein ◽  
Reversible Addition ◽  
Poly Ethylene

A series of well defined semitelechelic and mid-functionalized poly(poly(ethylene glycol) methyl ether methacrylate)s (poly(PEGMA)s) were synthesized through reversible addition-fragmentation chain transfer (RAFT) polymerization using thiazolidine-2-thione-functionalized chain transfer agents (CTAs). The thiazolidine-2-thione group was located either at the end or in the middle of polymer chains depending on the different structural CTAs. All polymers were fully analyzed by 1H NMR spectroscopy and GPC, confirming their well-defined structures, such as predesigned molecular weights, narrow polydispersity indices, and high yield chain-end or chain-middle functionalization. The thiazolidine-2-thione functionality located at the end of or at the middle of the polymer chains can react with amine residues on protein surfaces, forming protein-polymer conjugates via amide linkages. The bioactivity of protein conjugates were subsequently tested using micrococcus lysodeikticus cell as substitute. The protein conjugations from the mid-functionalized polymer remained much more protein bioactivity comparing to their semitelechelic counterpart with similar molecular weights, indicating the steric hindrance of the mid-functionalized poly(PEGMA)s lead to the better selective conjugation to protein. The number of polymer chains on the protein surface was additionally evaluated by TNBS analysis, exhibiting that there are less mid-functionalized poly(PEGMA)s linked on the protein surface than the semitelechelic polymers, also supporting the hypothesis that the steric hindrance from branch-structural polymers results in the better reaction selectivity. This synthetic methodology is suitable for universal proteins, seeking a balance between the protein bioactivity and the protein protection by the covalent linkage with polymer, and exhibits promising potential for pharmaceutical protein conjugation.

Syntheses of 2-(trifluoromethyl)acrylate-containing block copolymers via RAFT polymerization using a universal chain transfer agent

2018 ◽  
Vol 9 (25) ◽  
pp. 3511-3521 ◽  
Author(s):  
Sanjib Banerjee ◽  
Marc Guerre ◽  
Bruno Améduri ◽  
Vincent Ladmiral
Keyword(s):  
Block Copolymers ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Chain Transfer Agent

2-(Trifluoromethyl)acrylate-containing block copolymers were synthesized via RAFT polymerization using a universal CTA.

RAFT Polymerization of 2,2,3,3-Tetrafluoropropyl Methacrylate in the Presence of Lewis Acids

2021 ◽  
Vol 899 ◽  
pp. 525-531
Author(s):  
Oleg A. Lebedev ◽  
Alexandra O. Grigoreva ◽  
Sergey D. Zaitsev
Keyword(s):  
Polymer Chain ◽  
Lewis Acids ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Point Of View ◽  
Chain Transfer Agent ◽  
Reversible Addition

The influence of various tacticity regulators on the reversible addition-fragmentation (RAFT) polymerization of 2,2,3,3-tetrafluoropropyl methacrylate in the presence of 2-cyano-2-propyldodecyltritiocarbonate as an chain transfer agent was investigated. Among Lewis acids considered, the polymerization of TFPMA in dioxane with ZnBr2 turned out to be the most effective from the point of view of tacticity; the polymer with the highest isotacticity is formed. The addition of hexafluoroisopropanol leads to an increase in the heterotacticity and a decrease in the isotacticity of the polymer chain.

Synthesis and Investigation of pH-Switchable RAFT Agent in Polymerization of Styrene

2021 ◽  
Vol 899 ◽  
pp. 638-643
Author(s):  
Artem Vlasov ◽  
Alexandra O. Grigoreva ◽  
Sergey D. Zaitsev
Keyword(s):  
Mass Distribution ◽  
Molar Mass ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Chain Transfer Agent ◽  
Molar Mass Distribution ◽  
Reversible Addition ◽  
Raft Agent ◽  
Kinetic Features

pH-switchable chain transfer agent 1-cyano-1-methylethyl (phenyl)(pyridin-4-yl)-carbamodithioate (CMPC) was synthesized and reversible addition-fragmentation chain-transfer (RAFT) polymerization of styrene in presence of CMPC was studied. It was shown that presence of CMPC affects molar mass distribution and kinetic features and realizes supposed mechanism of RAFT polymerization. Different effect of CMPC on polymerization of styrene in presence of protic acids was studied.

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