Dissolution of silk fibroin with calciumchloride/ethanol aqueous solution

摘要

Fibroin was dissolved in a solution of calcium chloride and water(molar ratio 1: 8) and a solution of calcium chloride, water and ethanol (molar ratio 1: 8: 2) which was made by adding 2 mol of ethanol to the former solution. Fibroin insoluble in the calcium chloride aqueous solution at 20 to 30 deg C (approx room temperature) for 240 to 720 hr, but was dissolved in the solution to which ethanol was added. Such longe-term treatment, however, involves cost problems. In order to cope with such problems, fibroin was treated with a calcium chloride aqueous solution at 40 to 60 deg C for 1 hr. The fibroin was dissolved to 0.7 to 3.3%. Treatment in the solution to which ehtanol was added at 55 deg C for 1 hr, vesulted in complete dissolution, which was approximately 35 times more likelythan with the calcium aqueous solution. Based on these results, the solution of calcium chloride, water and ethanol (molar ratio 1: 8: 2) was considered to be very promising as a solvent of bio-material fibroin, from a viewpoint of industrial application.