EDC Induced Silk Fibroin to Prepare Silk Films with Enhanced Water Stability and Extensibility
In order to expand the application of silk fibroin (SF) films in skin tissue engineering, this study prepared SF aqueous solutions containing a certain proportion of the crosslinking agent 1-ethyl-3-( 3-dimethylaminopropyl) carbodiim-ide ( EDC) , and obtained SF films with enhanced water stability and extensibility. The study characterized and analyzed the dissolution rate, mechanical properties, degree of crosslinking, and secondary structure of the obtained SF films. Compared to the pure SF films ( SFF) , the dissolution rate of EDC-treated SF films ( SFF-EDC) decreased significantly from 98. 2% to 6. 1%. In terms of mechanical properties, the fracture elongation of SFF-10EDC prepared with the mass ratio of EDC:SF being 10:100 reached 170. 97%, which was 60 times higher than that of the SFF. EDC was observed to induce the formation of amide bonds within and between SF molecules, promoting the transformation of SF molecular conformation from random coil to β-sheet structure. These results suggest that EDC, in addition to acting as a crosslink-ing agent, also serves as a plasticizer in interaction with SF. This study provides a new method for constructing flexible SF films.