Characterization of silk hydrogel formed with hydrolyzed silk fibroin-methacrylate via photopolymerization

Silk fibroin (SF) hydrogel has been highlighted for its unique physical property as well as biocompatibility. SF hydrogel is easily formed from aqueous solution by physical crosslinking via β-sheet structure formation. However, such a physically formed SF hydrogel is mechanically poor with low reproducibility. Alternatively, SF hydrogel formation can be achieved by chemical cross-linking, which is able to precisely control the network density with high reproducibility. Nevertheless, chemical cross-linking process is very restricted for SF since it is very difficult to maintain homogeneous reaction condition in SF solution. To achieve controlled crosslinking, we synthesized SF-methacrylate (SFMA) with hydrolyzed SF and fabricated SF hydrogel via photo-crosslinking in the presence of photoinitiator. SFMA powder synthesized with 25 kDa SF showed good water-solubility at various degrees of methacrylation as well as quick gelation time (<60 s). In addition, the photo-crosslinked SF hydrogel showed a wide property control range with higher elasticity compared to physically crosslinked SF hydrogel.