Thiolation and characterization of regenerated Bombyx mori silk fibroin films with reduced glutathione

摘要

Bombyx mori silk fbroin-based materials have good biocompatibility and biodegradability. In order to maximizetheir utility while maintain appropriate features, silk fbroin (SF) flms were modifed with reduced glutathione (GSH)(NH2)–ECG–(COOH), using the carbodiimide chemistry method, for the introduction of thiol groups onto surfaces. Theefects of this modifcation on SF flms’ chemical and physical properties, and cytotoxicity were assessed. The chemicaland elemental composition analysis results suggested that reduced glutathione (GSH) was covalently coupled ontothe surface of silk fbroin flms. Atomic force microscopy (AFM) results indicated the surface roughness of silk fbroinflm was increased after the modifcation by GSH. The GSH-modifed silk fbroin flms also showed the smaller contactangle due to the hydrophilic peptides coupled on the flm surface. Through MTT assay, it was shown that the chemically modifed SF flm was not cytotoxic to HEK293 cells, and it had no adverse infuence on the growth of HEK293cells. Our approach provides a new option to engineer SF-based material surface with thiol groups in order to allowfor secondary reactions and holds great promise for applications of SF-based materials in the biomedical feld.