MOF-encapsulated copper-doped carbon dots nanozymes with excellent biological activity promote diabetes wound healing.

Abstract

Poor wound healing in diabetics is primarily caused by persistently high levels of inflammation and recurrent bacterial infections. The catalytic therapy technique based on nanozyme medicine has emerged as a beacon of hope for patients with diabetic wounds. However, the use of a single-atom nanozyme may still have limitations, including nanozyme burst release, immunological clearance and insufficient antibacterial activity. To address the aforementioned problems, we provide a new nano-catalytic therapeutic agent for diabetic skin ulcers that incorporates a single-atom nanozyme with high antioxidant activity into a metal-organic framework (ZIF-Cu/C-dots). First, a Cu single-atom nanozyme supported by ultra-small carbon dots (Cu/C-dots) with high antioxidant activity was created. A nanozyme-integrated metal-organic framework was then created, utilizing Cu/C-dots as ligands and Zn²⁺ as the core metal. Cu/C-dots have good oxidase-like activity, shielding the biological system from ROS damage and reducing the expression of TNF-α and IL-1β. Zn²⁺ also has good antibacterial activity (the antibacterial rate was more than 90%). This integrated technique prevents nanozyme aggregation, improves nanozyme biocompatibility, slows down the breakdown of ZIF and allows for the regulated release of Cu/C-dots and Zn²⁺ as needed. Finally, in vivo studies have shown that ZIF-Cu/C-dots can effectively alleviate inflammation at the site of diabetic wounds, accelerate vascular regeneration, promote collagen deposition and enhance tissue remodeling, serving as a novel nano-catalytic platform for the treatment of wounds that are difficult to heal.