Multifunctional Hydrogel with Photothermal ROS Scavenging and Antibacterial Activity Accelerates Diabetic Wound Healing.

Poor diabetic wound healing poses a critical threat to human health. Excessive oxidative stress and increased susceptibility to bacterial infection are key issues that impede diabetic wound healing. Cerium oxide nanoparticles (CeO2 NPs) have attracted increasing attention because of their unique antioxidant and antimicrobial properties. Here, this work designs a near-infrared (NIR) light-responsive gelatin methacryloyl (GelMA)/CeO2/polydopamine (PDA) hydrogel with antibacterial and antioxidant effects. The hydrogel exhibits a stable, efficient, and controllable photothermal conversion capacity under NIR stimulation. The hydrogel can be used to construct a local microenvironment conducive to chronic diabetic wound healing. Significant antibacterial effects of the NIR-responsive GelMA/CeO2/PDA hydrogel on both Escherichia coli (E.coli) and methicillin-resistant Staphylococcus aureus (MRSA) are demonstrated by counting colony-forming units (CFUs) and in bacterial live/dead staining experiments. The strong antioxidant activity of hydrogels is demonstrated by measuring the level of reactive oxygen species (ROS). The effect of the NIR-responsive GelMA/CeO2/PDA hydrogel in terms of promoting diabetic wound healing is validated in full-thickness cutaneous wounds of diabetic rat models. Additionally, this work describes the mechanism by which the NIR-responsive GelMA/CeO2/PDA hydrogel promotes diabetic wound healing; the hydrogel inhibits the interleukin (IL)-17 signaling pathway. This NIR-responsive, multifunctional hydrogel dressing provides a targeted approach to diabetic wound healing.