Preparation,characterisation and controlled drug release from thermosensitive hybrid hydrogels

Abstract

Temperature sensitive hydrogels are probably the most commonly studied class of environmentally sensitive polymer systems in drug delivery research. In this study, polyvinyl alcohol (PVA) matrix with nanosized pores was obtained by treatment with silica and glutaraldehyde. Then, the internal pores of the dry PVA matrix were filled with poly(N-isopropylacrylamide) (PNIPAAm) hydrogels to form a thermoresponsive hybrid PVA/PNIPAAm hydrogel for controlled drug release. The morphology and functional groups of the hybrid hydrogel were characterised by SEM and Fourier transform infrared spectroscopy. The swelling kinetics and the temperature dependence of equilibrium swelling ratio in distilled water were also investigated. Rhodamine B was loaded to the hybrid hydrogels for release study, and the release rate was fast when the temperature was above the lower critical solution temperature of PNIPAAm. The release data suggest that an excellent controlled release can be achieved by the hybrid hydrogel without losing the intelligent properties of the PNIPAAm hydrogel.