Tissue adhesive hydrogel based on upcycled proteins and plant polyphenols for enhanced wound healing

This study investigates the potential of keratin and silk as natural structural proteins for designing tissue adhesives for wound healing. The study demonstrates the silk-wool-tannic acid (SF-Wool-TA) complex as an in situ tissue adhesive through the utilization of polyphenol chemistry. Keratin is first isolated from coarse sheep wool using a green microwave treatment process. Due to the presence of functional groups such as tyrosine, carboxyl, and thiol groups; silk, and keratin can form multiple interactions with pyrogallol and catechol functional groups of TA to form an in situ adhesive hydrogel. The SF-Wool-TA hydrogel exhibits in situ gelation, recyclability, moldability, elasticity (G'>100 kPa), adhesiveness, self-healing properties, 3D printability, antibacterial activity, antioxidant properties, and biocompatibility. The inclusion of wool keratin also enhances the hydrophilicity of the hydrogel. The hydrogel was tested in vivo and enhanced wound healing in a full-thickness skin incision model. The keratin-polyphenol interaction represents an attractive hybrid material for advanced biomaterials applications, particularly in the field of skin wound healing.