Chitosan-g-PLGA copolymer as a thermosensitive membrane

A thermosensitive copolymer was synthesized by graft copolymerization of poly(lactide-co-glycolide) (PLGA) copolymers onto the surface of chitosan membranes. Acryloyl chloride was used as a coupling reagent for the covalent attachment of PLGA to the chitosan membranes. FTIR spectroscopy and DSC analysis were used to characterize the resulting graft copolymer. Thermosensitive swelling behaviors of the copolymer were investigated as well. The membranes exhibited reversible swelling-shrinking behavior; higher swelling ratios were obtained observed at higher temperatures. Drug permeation studies were carried out using vancomycin hydrochloride and betamethasone sodium phosphate as the model drugs. The permeability coefficient of vancomycin was found to be a discontinuous function of temperature; the permeability increased steeply above the upper critical solution temperature (UCST) of the membranes. Considering the high biocompatibility of chitosan and PLGA, these thermosensitive chitosan-g-PLGA membranes might be used to develop an intelligent drug delivery system. (C) 2009 Elsevier Ltd. All rights reserved.