Preparation, characterization and in vitro study of biocompatible fibroin hydrogel

In this study, Bombyx mori silk based hydrogels were prepared and their biorelevant properties like physical, chemical and thermal properties were studied. Firstly, silk fibroin aqueous solution was prepared and the molecular weight of fibroin protein was determined followed by particle size analysis for the confirmation of study. Silk fibroin hydrogels were prepared by treating a 12% (w/v) silk fibroin aqueous solution at 4°C (thermgel) and lyophilized. The swelling and thermorheological behaviour of fibroin hydrogels were studied. The morphology and crystalline structure of lyophilized hydrogels were investigated by scanning electron microscopy (SEM) and wide-angle diffractometry, respectively while the surface functional groups were analyzed by FT-IR. The thermal behavior was also studied by means of differential scanning calorimetry and gravimetric method. The cytocompatibility of the hydrogels was evaluated through three-dimensional culture with human peripheral blood mononuclear cells. Lyophilized fibroin gel of high strength and high thermal stability were obtained. The β-crystelline structure of lyophilized fibroin hydrogel has shown excellent swelling capacity to mimic the living tissues. The surfaces of these hydrogels were found supporting to cell adherence and proliferation. hMNCs could survive and proliferate in the gel within 3 weeks, and the gel had good cytocompatibility. It was concluded that fibroin hydrogel not only has interpenetrating network structure but also has good cytocompatibility and could be used as injectable scaffolds able to promote in situ bone regeneration.Key words: Fibroin, hydrogel, tissue engineering, sodium dodecyl sulfate polyacrylamide gel electrophoresis, scanning electron microscopy, cytocompatibility