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 of bacterial infection, oxidative imbalance, deficient blood vessels and low regenerative ability. Bioactive glasses (BGs) play an important role in the late stages of healing due to their ability to promote vascular network formation and collagen fiber deposition. However, infection and oxidative stress in the early form a terrible wound microenvironment by destroying cells and growth factors to badly inhibit wound healing. Therefore, it is critical to develop a material involved in regulating the whole healing phases. In this work, bioactive glasses-based nanozymes (MnO 2 @PDA-BGs) with antioxidation, antibacterial and pro-healing abilities were synthesized by the redox deposition of MnO 2 on mesoporous BGs. Afterwards, cryogel with the interconnected macropore structure was fabricated by the polymerization of methacrylate anhydride gelatin (GelMA) at -20 °C, which is conducive to substance exchange, vascular ingrowth and ECM deposition. MnO 2 @PDA-BGs were loaded into the cryogel to obtain nanocomposite cryogel (MnO 2 @PDA-BGs/Gel) with good SOD, CAT-like activities to eliminate ROS, such as ·OH, H 2 O 2 and ·O 2 - . Besides, MnO 2 @PDA-BGs/Gel had intensive POD-like activity under acidic condition and good NIR photothermal responsiveness to achieve excellent antibacterial performance. Cells experiments demonstrated that MnO 2 @PDA-BGs/Gel recruited L929s and promoted their proliferation due to the good bioactivity of BGs. Furthermore, MnO 2 @PDA-BGs/Gel eliminated intracellular overexpressed ROS and maintained the viability of L929s. Animal experiments confirmed that MnO 2 @PDA-BGs/Gel promoted wound healing and avoided scarring by killing bacteria, reversing inflammation, promoting vascularization, and also improving the deposition of collagen III. This article is protected by copyright. All rights reserved.