Synthesis and self-assembly of tunable thermosensitive chitosan amphiphilic copolymers by click chemistry

Amphiphilic chitosan-graft-P(2-(2-methoxyethoxy)ethyl methacrylate-co-oligo(ethylene glycol) methacrylate) (CS-g-P(MEO(2)MA-co-OEGMA)) copolymers were synthesized by the "graft onto" method via click chemistry. The graft copolymers were characterized by H-1 NMR and ATR FT-IR measurements. The self-assembly behavior and tunable thermosensitive properties of CS copolymers in water were investigated by TEM, DLS, and transmittance. The lower critical solution temperature (LCST) values of CS copolymer micelle solutions were tuned by altering the molar ratio of MEO(2)MA and OEGMA in copolymers. Furthermore, the copolymer micelles can reversibly swell and shrink in response to external temperature. The obtained tunable thermosensitive amphiphilic CS copolymers have both the unique properties of P(MEO(2)MA-co-OEGMA) and chitosan, and will have the potential applications in the biomedical field. (C) 2010 Elsevier B.V. All rights reserved.