Chain extension by diisocyanate condensation provides a versatile and convenient means for preparing block copolymers. We have utilized this chemistry to prepare reducible multiblock polycations for siRNA delivery. This approach, an alternative to oxidative coupling, was suitable for preparing multiblock polycations with defined molecular weight and architecture. The polymer, PEG-b-multi-(polyhexylurea-co-oligo-L-lysine)-b-PEG, was capable of electrostatically condensing siRNA to form nano-sized polyplexes across a broad compositional range. We demonstrated that the polyplexes enter the cells via endocytosis and interact with the endosome membrane leading to destabilization and hence endosome escape. Another feature of these polymers is their multiple intra-chain disulfide linkages. This enables weakening of the polyplex via chain scission within the cytosol's reductive environment. In addition to the controlled preparation of the polymer, the polyplexes were capable of delivering siRNA in vitro to silence greater than 50% green fluorescent protein expression with negligible toxicity.
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http://dx.doi.org/10.1016/j.actbio.2013.05.011 | DOI Listing |
Drug Deliv Transl Res
January 2025
Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, T6G 2E1, Canada.
In this study, a novel inhibitor of ERCC1/XPF heterodimerization, A4, was used as an inhibitor of repair for DNA damage by platinum-based chemotherapeutics. Nano-formulations of A4 were developed, using self-assembly of the following block copolymers: methoxy-poly(ethylene oxide)-block-poly(α-benzyl carboxylate-ε-caprolactone) (PEO-b-PBCL), methoxy-poly(ethylene oxide)-block-poly(ε-caprolactone) (PEO-b-PCL), or methoxy-poly(ethylene oxide)-block-poly (D, L, lactide) (PEO-b-PDLA 50-50). The nano-formulations were characterized for their average diameter, polydispersity, morphology, A4 encapsulation and in vitro release.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Chang Chun Institute of Applied Chemistry Chinese Academy of Sciences, Key Laboratory of Polymer Ecomaterials, 5625 Renmin Street, Changchun, , 130022, Changchun, CHINA.
Living cationic polymerization (LCP) is a classical technique for precision polymer synthesis; however, due to the high sensitivity of cationic active species towards chain-transfer/termination events, it is notoriously difficult to control polymerization under mild conditions, which inhibits its progress in advanced materials engineering. Here, we unlock a practical anion-binding catalytic strategy to address the historical dilemma in LCP. Our experimental and mechanistic studies demonstrate that commercially accessible hexafluoroisopropanol (HFIP), when used in high loading, can create higher-order HFIP aggregates to tame dormant-active species equilibrium via non-covalent anion-binding principle, in turn inducing distinctive polymerization kinetics behaviors that grant efficient chain propagation while minimizing competitive side reactions.
View Article and Find Full Text PDFBiomater Sci
January 2025
Zhejiang Key Laboratory of Smart BioMaterials, and College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, China.
Accurate imaging of tumor hypoxia is critical for early cancer diagnosis and clinical outcomes, highlighting the great need for its detection specificity and sensitivity. In this report, we propose a probe (HTRNP) that simultaneously has hypoxia-targeting and hypoxia-responsive capabilities to enhance the tumor hypoxia imaging efficiency. HTRNP was successfully prepared through the encapsulation of Pt(II)-tetrakis(pentafluorophenyl)porphyrin (PtPFPP), which exhibits hypoxia-dependent phosphorescence, within the amphiphilic block copolymer OPDMA-PF, which has hypoxia-targeting tertiary amine -oxide moieties and hydrophobic perfluorobenzene ring structures, which highly improved the loading content and water solubility of PtPFPP.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
Chimie ParisTech, CNRS, Institut de Recherche de Chimie Paris, PSL University, Paris, 75005, France.
The development of catalysts that are both robust and highly active at room temperature can often be seen as a major challenge in anionic polymerization. However, these properties are desirable for polymer synthesis because they allow for easy and sustainable production of interesting materials. Here, iron and magnesium complexes are used to form in situ generated metalate complexes that are shown to be highly active in the room temperature copolymerization of methyl methacrylate and lactide.
View Article and Find Full Text PDFChemistry
January 2025
Beijing Institute of Technology, Polymer Materials, 5 Zhongguancun Nandajie, 100081, Beijing, CHINA.
The self-assembly of block copolymers (BCPs) to form nanostructures of various morphologies and controllable dimensions has been a very promising research area in nanotechnology in recent decades. This review mainly summarizes the recent advances in precise and controllable self-assembly of BCPs through a tailored nucleation-growth strategy to modulate the self-assembly behavior of the BCPs. These efforts have led to a better understanding of the self-assembly mechanisms and opened new possibilities for creating novel materials with designable properties.
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