Bioactive Glasses-Based Nanozymes Composite Macroporous Cryogel with Antioxidative, Antibacterial, and Pro-Healing Properties for Diabetic Infected Wound Repair

The treatment for diabetic ulcers still remains a big clinic challenge owing to the adverse repair microenvironment. Bioactive glasses (BGs) play an important role in the late stages of healing due to their ability to promote vascularization and collagen fiber deposition, but fail to improve infection and oxidative stress in the early stage.Therefore, it is critical to develop a material involved in regulating the whole healing phases. In this work, BGs-based nanozymes (MnO₂ @PDA-BGs) with antioxidation, antibacterial and pro-healing abilities are synthesized by the redox deposition of MnO₂ on mesoporous BGs. Afterward, cryogel with the interconnected macropore structure is fabricated by the polymerization of methacrylate anhydride gelatin (GelMA) at -20 °C. MnO₂ @PDA-BGs are loaded into the cryogel to obtain nanocomposite cryogel (MnO₂ @PDA-BGs/Gel) with multiple enzymes-like- activities to eliminate reactive oxygen species (ROS). Besides, MnO₂ @PDA-BGs/Gel has intensive peroxidase-like activity under acidic condition and near infrared photothermal responsiveness to achieve excellent antibacterial performance. Cells experiments demonstrate that MnO₂ @PDA-BGs/Gel recruits L929s and promotes their proliferation. Furthermore, MnO₂ @PDA-BGs/Gel eliminates intracellular overexpressed ROS and maintains the viability of L929s. Animal experiments confirm that MnO₂ @PDA-BGs/Gel promotes wound healing and avoided scarring by killing bacteria, reversing inflammation, promoting vascularization, and improving the deposition of collagen III.