Injectable stretchable self-healing dual dynamic network hydrogel as adhesive anti-oxidant wound dressing for photothermal clearance of bacteria and promoting wound healing of MRSA infected motion wounds

Due to the frequent movement and stretching of skin, traditional wound dressings are difficult to adapt to motion wounds on the stretchable parts of the body surface (e.g. elbow, hip and knee). Moreover, chronic motion wounds are often accompanied by infections. To address these issues, a series of injectable adhesive self-healing photothermal dual dynamic Schiff base network hydrogels were developed based on adipic dihydrazide modified hyaluronic acid, benzaldehyde group functionalized poly(ethylene glycol)-co-poly(glycerol sebacate) and cuttlefish melanin nanoparticles, and their excellent tissue adhesion, stretchability and self-healing properties enable them to adapt to the frequent movement of motion wounds. Meanwhile, the hydrogels can prevent and treat motion wound infections through photothermal antibacterial therapy, and exhibit multifunctions (including anti-oxidation, hemostasis, exudate absorption and sustained release property) to promote wound healing. In in vivo normal and infected full-thickness skin defect motion wound models, the hydrogel dressings significantly prevented wound infections and promoted wound healing with milder inflammation, higher granulation tissue thickness and collagen disposition. Overall, the adhesive self-healing photothermal hydrogels can adapt to frequent movement of motion wounds, and can improve infection and promote healing in both normal and infected motion wounds, indicating their great potential in motion wound treatment in clinics.