Recently, silk sericin has been studied extensively for biomedical and cosmetic applications because of its unique properties, including UV resistance and wound healing ability. For use in applications, sericin is fabricated in various forms including...
Recently, silk sericin has been studied extensively for biomedical and cosmetic applications because of its unique properties, including UV resistance and wound healing ability. For use in applications, sericin is fabricated in various forms including films and gels. However, the mechanical properties of sericin are too weak. In this basic study on improving the mechanical properties of sericin, a silk sericin aqueous solution was separated into two layers by centrifugation. The solution viscosity, molecular conformation, and mechanical properties of each separation layer of the sericin were examined. Sericin from the lower layer had a higher solution viscosity and film mechanical properties (strength and strain) than that from the upper layer, implying that sericin from the lower layer had a higher molecular weight than that from the upper layer. The molecular conformation of the sericin films varied depending on the casting solvent. In aqueous solution, the sericin film from the lower layer showed a b -sheet conformation, whereas that from the upper layer displayed a random coil conformation. All the sericin films showed a highly β-sheet-crystallized state when cast in formic acid, regardless of the separation layer.