Oxidation-Responsive OEGylated Poly-l-cysteine and Solution Properties Studies

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• 作者：Xiaohui Fu ; Yinan Ma ; Yong Shen ; Wenxin Fu ; Zhibo Li
• 刊名：Biomacromolecules
• 出版年：2014
• 出版时间：March 10, 2014
• 年：2014
• 卷：15
• 期：3
• 页码：1055-1061
• 全文大小：421K
• 年卷期：v.15,no.3(March 10, 2014)
• ISSN：1526-4602

文摘

The oxidation-responsive behaviors of OEGylated poly-l-cysteine homopolypeptides, that is, poly(l-EG_xMA-C)_n, were investigated. These poly-l-cysteine derivatives adopted mixed conformation in water, in which the 尾-sheet accounted for a significant proportion. Upon oxidation, the thioethers in polypeptide side chains were converted to polar sulfone groups, which triggered the secondary structure transition from 尾-sheet preferred conformation to random coil. Accordingly, the increase of side-chain polarity together with conformation changes increased samples鈥?water solubility and cloud point temperature. Using mPEG₄₅-NH₂ as macroinitiator, we synthesized PEG₄₅-b-poly(l-EG₂MA-C)₂₂ diblock copolymer via ring-opening polymerization (ROP) of l-EG₂MA-C N-carboxyanhydride (NCA). The PEG₄₅-b-poly(l-EG₂MA-C)₂₂ was able to self-assemble into spherical micelles in aqueous solution, and the micelles could undergo an oxidation-triggered disassembly due to the oxidation-responsive thioethers. Such a new class of oxidation-responsive polypeptides might provide a promising platform to construct inflammation targeting drug delivery systems.