A novel temperature-sensitive semi-interpenetrating (semi-IPNs) hydrogels based on biocompatible silk sericin (SS) and poly(N-isopropylacrylamide) (PNIPAM) were prepared by semi-IPNs method in aqueous solution. The (de)swelling behaviors, temperature-sensitivity, maximum swelling degree and impulse response behaviors of the hydrogels were studied by weighing method. The interior morphology, phase transition behaviors and dependence of storage modulus on temperature of the hydrogels were investigated by means of scanning electron microscope (SEM), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA), respectively. The results showed that the incorporation of high hydrophilic SS increases the pore size of the semi-IPNs hydrogels, resulting in higher swelling degree and apparent decrease of storage modulus upon temperature. In comparison with traditional PNIPAM hydrogel, the deswelling ratios and lower critical solution temperature (LCST) of the semi-IPNs hydrogels haven t obvious difference.

Key words: hydrogels, silk sericin, N-isopropylacrylamide, semi-interpenetrating network, biocompatibility