Process for producing functional silk fibroin and utilization of the same

Abstract

Provided is a process for producing undegraded silk fibroin, which comprises dissolving a cocoon layer or cocoon yarn of fresh, dry or cooked cocoons, raw silk, or silk fabrics, or residual yarns thereof in an aqueous solution of a neutral salt, and then subjecting the resulting solution to fractional precipitation to separate silk fibroin from silk sericin; subjecting the resulting solution to the following step a) or b): a): treatment with an alkaline aqueous solution under mild conditions, b) treatment with an aqueous urea solution under mild conditions, thereby removing silk sericin; or subjecting the resulting solution to treatment with pressurized hot water or enzymatic degumming. The present invention makes it possible to produce undegraded silk fibroin (molecular weight: 350000 to 370000) with industrial advantage comparable in function to that obtained from liquid silk. From the thus-obtained silk fibroin, excellent additives for cell culture, wound healing promoters and cosmetic compositions.

Dependencies are inferred from the claim text.