Highly Stretchable, Transparent, and Adhesive Double-Network Hydrogel Dressings Tailored with Fish Gelatin and Glycyrrhizic Acid for Wound Healing

It remains challenging to fabricate highly stretchable and adhesive hydrogel dressings for wound healing using simple, safe, and green methods. Herein, inspired by the main components of snail mucus, a fully physical double-network (DN) hydrogel dressing composed of fish gelatin (FGel) and glycyrrhizic acid (GL) was fabricated, in which FGel provided a protein scaffold to mimic snail mucus proteins, while GL mimicked the adhesion and bioactivity of snail mucus because of its abundant carboxyl and hydroxyl groups and intrinsic immunomodulatory activity. As expected, the obtained FGel/GL hydrogel dressings exhibited outstanding mechanical and adhesive performances (flexibility, stretchability, adhesive ability, and removability), high transparency, and good antifreezing properties. More importantly, they also possessed excellent biocompatibility, cell migration, and angiogenesis ability in vitro experiments. Finally, animal experiments in vivo indicated that the FGel/GL hydrogel dressings significantly promoted full-thickness wound healing, including promoting granulation tissue formation, collagen deposition, and skin angiogenesis and inhibiting the inflammatory response. All these findings indicated that the FGel/GL hydrogel dressings have great potential for applications in the clinical treatment of wound healing.