Immunity-modulated photocatalytic composite hydrogel for diabetes wound treatment

The management of type 1 diabetes mellitus (T1DM) wounds presents a pressing challenge due to the complicated pathological microenvironments and autoimmune destruction of pancreatic islets. In this study, g-C 3 N 4 /Ag nanosheets and glucose oxidase (GOx) were encapsulated within ZIF-8 to form a photocatalytic nanocomposite (AGZ). GOx catalyzes the oxidation of glucose at the wound site, generating gluconic acid and H 2 O 2 . The reduction in pH levels triggers the disintegration of the ZIF-8 framework, leading to the release of g-C 3 N 4 /Ag and Zn 2+ . The g-C 3 N 4 /Ag nanosheets promote the generation of ·OH by catalyzing H 2 O 2 under visible light, thereby synergistically enhancing the antibacterial efficacy together with Zn 2+ . The immunomodulatory photocatalytic composite hydrogel (AGZ@G) was synthesized via Schiff base bond formation, exhibiting self-healing, injectable, antibacterial, and hemostatic properties. AGZ@G demonstrates the ability to combat bacterial infections, stimulate collagen synthesis, reduce inflammation, induce M2 macrophage polarization, and promote angiogenesis, thereby expediting wound healing in individuals with T1DM. Additionally, the hydrogel aids in the restoration of islet function by inhibiting ZnT8 expression via Zn 2+ release and mitigating islet inflammation.