Cell immobilization TSCs of mulberry silkworms were purchased from a local silk factory (Yala, Thailand) (Fig. 1). Cell immobilization was performed as follows. 2.5 g of TSCs and 250 mL of culture medium in 500 mL flasks were autoclaved separately for 15 min at 121 °C. 10 mL of stock cell suspension was then added to the sterilized culture medium. The sterilized TSCs were immersed in the culture medium and incubated at 150 rpm and 33 °C for 24 h to induce natural cell adhesion.