A functional hydrogel dressing based on glycyrrhizic acid with low-swelling and moisturizing properties for enhancing infected wound repair

Wound healing is a challenging due to the presence of bacterial infection, excessive inflammation and angiogenesis disorders. While traditional therapies struggle, a functional hydrogel can effectively repair wounds. However, the use of hydrogels is limited due to their high swelling and excessive dehydration characteristics. Herein, an interpenetrating polymer network hydrogel (HGP@EGCG) based on hyaluronic acid methacrylate (HAMA), glycyrrhizic acid (GA), polyvinyl alcohol (PVA), epigallocatechin-3-gallate (EGCG), and glycerin/water binary solvent was developed by self-assembly, physical entanglement and chemical crosslinking for infected wound healing. GA forms a primary network through self-assembly induced by Zn2+ and HAMA forms a more robust network structure through free radical polymerization as a rigid backbone, followed by the physical entanglement of PVA, which provides additional crosslinks within the network. The robust network structure conferred the HGP hydrogel with low swelling properties. HGP@EGCG hydrogels could adhere to the wound surface, exhibiting adequate tensile and compressive strength to withstand deformations induced by external forces. Then HGP@EGCG hydrogels with good moisture retention could facilitate the maintenance of wound hydration and prolong usage. Moreover, HGP@EGCG hydrogels could release the drug rapidly in an acidic environment and eliminate bacteria. The designed hydrogels demonstrated multifaceted functionality, including suitable adhesion, low swelling, good moisture retention, and efficient antibacterial properties. Both in vitro and in vivo investigations confirmed that HGP@EGCG hydrogels had good biocompatibility and promoted human umbilical vein endothelial cell migration and tube formation, which markedly expedited wound healing. Consequently, HGP@EGCG hydrogels present a broad spectrum of potential applications in the clinical treatment of infected wounds.