ExtHeat treatment. A high temperature and high pressure degumming technique was used to
prepare heat-degraded silk sericin solution. Cocoons of Bombyx mori silkworms were cut into
square pieces (about 5 mm2), and silk sericin was extracted in purified water (1 g of dry silk
cocoon: 30 ml of water) using autoclaving (SS-320, Tomy Seiko Co., Ltd., Tokyo, Japan) at 120C
for 60 min. The silk sericin solution was filtered to remove fibroin.