Physical Double-Network Hydrogel Adhesives with Rapid Shape Adaptability, Fast Self-Healing, Antioxidant and NIR/pH Stimulus-Responsiveness for Multidrug-Resistant Bacterial Infection and Removable Wound Dressing

Developing physical double-network (DN) removable hydrogel adhesives with both high healing efficiency and photothermal antibacterial activities to cope with multidrug-resistant bacterial infection, wound closure, and wound healing remains an ongoing challenge. An injectable physical DN self-healing hydrogel adhesive under physiological conditions is designed to treat multidrug-resistant bacteria infection and full-thickness skin incision/defect repair. The hydrogel adhesive consists of catechol-Fe3+ coordination cross-linked poly(glycerol sebacate)-co-poly(ethylene glycol)-g-catechol and quadruple hydrogen bonding cross-linked ureido-pyrimidinone modified gelatin. It possesses excellent anti-oxidation, NIR/pH responsiveness, and shape adaptation. Additionally, the hydrogel presents rapid self-healing, good tissue adhesion, degradability, photothermal antibacterial activity, and NIR irradiation and/or acidic solution washing-assisted removability. In vivo experiments prove that the hydrogels have good hemostasis of skin trauma and high killing ratio for methicillin-resistant staphylococcus aureus (MRSA) and achieve better wound closure and healing of skin incision than medical glue and surgical suture. In particular, they can significantly promote full-thickness skin defect wound healing by regulating inflammation, accelerating collagen deposition, promoting granulation tissue formation, and vascularization. These on-demand dissolvable and antioxidant physical double-network hydrogel adhesives are excellent multifunctional dressings for treating in vivo MRSA infection, wound closure, and wound healing.