Biocompatibility of hydrophilic regenerated Antheraea mylitta silk fibroin

Abstract

Silk, a natural biopolymer, is used for both textile and biomedical applications. Natural biopolymers are currently being used in various fields such as tissue engineering, wound healing, and food packaging based on their intrinsic qualities of safety, biocompatibility, and biodegradability, which make them the material of choice. Silk fibroin proteins from the Antheraea mylitta wild silkworm are the least studied in the field of biomaterials. The β-sheet structures found in non-mulberry silk fibroin protein improve its mechanical properties. The present study was undertaken to regenerate water-soluble A. mylitta silk fibroin to improve its applications and enhance fabrication efficiency. The silk fibroin was regenerated by dissolving degummed silk fibers in calcium nitrate tetrahydrate salt at 100°C for 3 h. The biophysical characterization of regenerated silk fibroin was carried out by X-ray diffraction, scanning electron microscope, Therapeutic Goods Administration, Fourier-transform infrared spectroscopy, and differential scanning calorimetry, confirming the indigenous aspects of the "regenerated silk fibroin (RSF)". CD spectra were employed to track α-helix to β-sheet conformational transition changes in RSF. MTT assays using NIH3T3 fibroblast cells revealed that the RSF exhibited no toxicity and resulted in the proliferation of cells.