A convenient way to synthesize comb-shaped chitosan-graft-poly (N-isopropylacrylamide) copolymer

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• 作者：Chen Chen^a ; Mingzhu Liu^a ; ^{mzliu@lzu.edu.cn} ; Chunmei Gao^a ; Shaoyu Lü ; ^a ; Jiucun Chen^a ; Xiyong Yu^b ; Enyong Ding^c ; Chuanming Yu^a ; Jing Guo^a ; Guijia Cui^a
• 关键词：Chitosan ; PNIPAAm ; Comb-shape ; pH/temperature multi-responsive ; ATRP
• 刊名：Carbohydrate Polymers
• 出版年：2013
• 出版时间：30 January, 2013
• 年：2013
• 卷：92
• 期：1
• 页码：621-628
• 全文大小：1046 K

文摘

Comb-shaped copolymers comprised of hydrophobic and hydrophilic blocks are self-assembled in aqueous solution, which results that they are suitable for delivery of hydrophobic drug molecules. Chitosan (CS) is an important biomaterial used widely in medical applications. Herein, a comb-shaped cationic copolymer composed of long biocompatible CS main chains and short PNIPAAm side chains was prepared via atom transfer radical polymerization (ATRP) by attaching an ATRP initiating group to N-phthaloyl chitosan. By subsequent removal of the protective groups on N-phthaloyl chitosan-graft-poly(N-isopropylacrylamide) (PHCS-g-PNIPAAm) copolymer with N₂H₄¡¤H₂O lead to the polymer pendant amino groups, this study attempted to synthesize a pH/temperature multi-responsive material. This chitosan-graft-poly(N-isopropylacrylamide) (CS-g-PNIPAAm) copolymer is self-assembled in aqueous solution into stimuli-responsive core-shell micelles with hydrodynamic diameters of about 170 nm. Structural organization and solution behavior were then investigated utilizing ¹H NMR spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS).