Nb ₂ C‐Reinforced Hydrogel Microneedle as Dual ROS‐Scavenging Platform to Promote Diabetic Wound Healing

Excessive and continuous production of reactive oxygen species (ROS) is a significant factor contributing to severe inflammation, bacterial infections, and poor angiogenesis, and it can also delay the healing of diabetic wounds. However, traditional clinical treatment methods are unable to effectively eliminate ROS. Herein, a dual ROS-scavenging platform that integrates multifunctional niobium carbide (Nb₂C) reinforced with curcumin (Cur) with UV-crosslinked hydrogel microneedles (MN) is presented. In this system, Cur, acting as the primary scavenger, can rapidly neutralize extracellular ROS. Under near-infrared (NIR) irradiation, the embedded Nb₂C not only triggers the on-demand release of curcumin but also, through its enzyme-like peroxidase-mimicking activity, acts as a secondary scavenger to eliminate deep intracellular ROS, thus providing a two-stage antioxidant defense mechanism. This NIR-enhanced dual-action synergistic effect can balance the oxidative microenvironment, promote the repolarization of macrophages from the M1 type to the M2 type, facilitate angiogenesis, and produce a powerful photothermal combined antibacterial effect. The results of in vivo experiments indicate that the use of Nb₂C-CurCD-GelMA MNs can significantly accelerate the healing of full-thickness diabetic wounds. The mechanism lies in coordinating the reduction of inflammation and tissue regeneration. This study offers a sophisticated and safe treatment strategy for refractory diabetic wounds.