Chitosan and gelatin based sprayable hydrogels incorporating photothermal and long-acting antibiotic sterilization for infected wound management with shape adaptability

Severe skin damage resulting from acute trauma is often accompanied by uncontrolled bleeding, microbial infections, and delayed wound healing. Herein, multifunctional sprayable hydrogels (CT-CS-ZIF@CIP Gel) were developed for wound management by incorporating antibacterial nanoplatforms (CT-CS-ZIF@CIP) into photocurable gels consisting of chitosan methacrylate and gallic acid grafted gelatin. The nanoplatform was initially constructed by sequentially loading Cu₂Se (CS) and ciprofloxacin-decorated zeolitic imidazolate framework-8 (ZIF@CIP) onto Cu-doped Ti MOF (CT), in which CS served as a photothermal agent, ZIF enabled pH-responsive release of CIP, and CT acted as carriers for CS and ZIF@CIP. The hydrogel precursor can be sprayed onto wound surface and photocured quickly, allowing hydrogel to fit the wound shape and form a protective barrier onsite. The resultant hydrogel exhibited excellent hemostatic ability, adhesion properties, cytocompatibility and toxin adsorption capacity. By integrating CS for short-term photothermal therapy with CIP for long-acting chemotherapy, the CT-CS-ZIF@CIP Gel demonstrated 100 % sterilization of three bacterial strains. Furthermore, moderate release of zinc and copper ions promoted wound healing. The therapeutic efficacy of hydrogel was validated in an infected cutaneous mouse model. Overall, this work presents a versatile sprayable hydrogel that can be flexibly applied to irregular dynamic wounds for safe and effective wound management.