Fabrication of Antheraea mylitta sericin hydrogel film via non toxic crosslinking citric acid with antioxidant properties

Sericin, a water-soluble protein biopolymer, is usually discarded as a byproduct of the silk processing industries. However, in recent years the applications of sericin biomacromolecule for biomaterial fabrication have increased. The current strategy of sericin hydrogel preparation involves crosslinking with glutaraldehyde or genipin which are known to be cytotoxic and hinder/restrict the biological applications of the end product. Therefore, citric acid, a nontoxic crosslinking agent, was explored for the fabrication of Antheraea mylitta sericin hydrogel films (AmSHF) with and without Polyethylene glycol (PEG). The biophysical characterization of fabricated hydrogel films confirmed the native properties of the natural silk in the regenerated sericin, as well as the AmSHF and appearance of the peak at 1709 cm(-1,) which indicated crosslinking of the hydrogel films due to the formation of ester bonds resulting in nanoscale roughness of 4.29 nm and amorphous nature with a higher swelling ratio of 18.76 +/- 0.058 g/g. The antioxidant nature of sericin was retained even after AmSHF formation as revealed by antioxidant assays. The AmSHF were also found to be cytocompatible and significantly increased the proliferation of NIH3T3 fibroblast cells. These results open up several possibilities for using these hydrogels as a biomaterial for wound healing and skin tissue regeneration.