Development of a thermo-sensitive hybrid hydrogel for slow release applications

In this thesis, synthetic poly (N vinyl caprolactam) (PNVCL) is particularly preferred for temperature-sensitive hybrid hydrogel synthesis because of its biocompatibility and low critical solution temperature (LCST) close to body temperature. Thermoresponsive PNVCL were combined with the semi synthetic polymer carboxymethyl celulose (CMC) and formed two hybrid hydrogels: Interpenetrating (IPN) PNVCL/CMC physical crosslinked blend hydrogel and PNVCL-g-CMCNH2 chemical crosslinked graft hydrogel to enhance mechanical and bioactive properties. Disc-shaped scaffolds were formed the hybrid hydrogels for drug release. The chemical structure of hydrogels (ATR-FTIR, HNMR, LCST, TGA/DSC, SEM) and some properties of scaffolds (water uptake, biodegredation, drug release, biocompatibility) were investigated. According to the results, crosslinking methods (physical and chemical crosslinking methods) to synthesize of both the hybrid hydrogels were successful and showed thermal sensitivity. The PNVCL/CMC blend and PNVCL-g-CMCNH2 graft hydrogels exhibited a distinct phase transition temperature at 32 and 39 ͦ C, respectively. PNVCL-g-CMCNH2 graft hydrogel exhibited temperature-dependent lidocaine release. Thus, PNVCL-g-CMCNH2 may have potential use in various biomedical applications, including controlled release.