Stabilization of Bombyx mori silk fibroin/sericin films by cross-linking

Silk fibroin and sericin have been widely used as a biomaterial for many different purposes. In this study, the properties of crosslinked fibroin/sericin 90/10 films have been investigated using two different crosslinkers poly(ethylene glycol) diglycidyl ether 600 (PEG-DE) and genipin. The films were characterized by molecular weight, fibroin conformation, crystallinity, and thermal stability. Both PEG-DE and genipin cross-linkers stabilized the random/α-helix structures in the fibroin and prevented phase separation between fibroin and sericin that occurs with non-crosslinked materials. The genipin crosslinked film displayed highest elongation at break and tensile strength. The in vitro cytotoxicity of the materials was assessed by lactate dehydrogenase activity and the viability was based on the tetrazolium salt and WST-1 tests. All films exhibited good biocompatibility and supported cell adhesion and proliferation.