Fabrication and in vitro evaluation of photo cross-linkable silk fibroin–epsilon-poly-L-lysine hydrogel for wound repair

Abstract

Abstract An optimal wound-healing hydrogel requires effective antibacterial properties and a favorable cell adhesion and proliferation environment. Although Bombyx mori silk fibroin (SF) possesses inherent wound-healing properties, it lacks these essential qualities. This study aimed to fabricate a novel photo-polymerizable hydrogel by utilizing SF’s wound-healing efficiency and the epsilon-poly-L-lysine (EPL) antimicrobial activity. The SF was modified with three different concentrations of glycidyl methacrylate (GMA) to obtain SF–GMA(L), SF–GMA(M), and SF–GMA(H). A methacrylated EPL (EPL–GMA) was also produced. Then, SF–GMA was mixed with EPL–GMA to produce photo-crosslinkable SF–GMA–EPL hydrogels. The SF–GMA(L)–EPL, SF–GMA(M)–EPL, and SF–GMA(H)–EPL hydrogels, fabricated with 20% EPL–GMA, demonstrated maximum antimicrobial activity and mammalian cell adhesion ability. The hydroxyl radical (•OH) scavenging efficiency of the hydrogels was tested and shown to be between 69% and 74%. These hydrogels also exhibited 60% efficiency in removing bacterial lipopolysaccharides. The water absorption ability of the hydrogels was consistent with the size of their internal pores. The hydrogels exhibited a slow degradation fashion, and their degradation products appeared cytocompatible. Finally, the elastomeric properties of the hydrogels were determined, and a storage modulus (G′) of 300–600 Pa was demonstrated. In conclusion, the hydrogels created in this study possess excellent biological and physical properties to support wound healing.