A NIR-II Laser-Triggered Nb2C-Arg/Gel Composite Multifunctional Hydrogel with Photothermal, ROS Scavenging, and NO Release for Infected Wound Healing

Infected wound healing remains a significant clinical challenge due to bacterial resistance and excessive inflammation. Herein, a multifunctional hydrogel dressing (Nb₂C-Arg/Gel) is developed that integrates two-dimensional Nb₂C nanosheets (photothermal agent) and arginine [nitric oxide (NO) donor] into a calcium ion cross-linked sodium alginate matrix. The hydrogel has a relatively high swelling capacity and good ability to scavenge reactive oxygen species (ROS), which are beneficial for absorbing wound exudate and reducing the inflammatory response of wounds. Under irradiation with a low-power NIR-II laser (1064 nm, 1 W cm^–2), Nb₂C-Arg/Gel achieves rapid photothermal heating (48.6 °C in 1 min), while thermally enhances arginine decomposition-triggered on-demand NO release. This synergistic mechanism provides superior antimicrobial efficacy against Staphylococcus aureus (97.65%) and methicillin-resistant S. aureus (90.05%). In vivo studies on MRSA-infected murine wounds demonstrate that the residual area on day 10 was 2.9%, which accelerated healing compared to that of the control group (17.8%), accompanied by reduced inflammation and enhanced angiogenesis. The excellent biocompatibility of hydrogel is validated by low hemolysis (<5%) and promoted fibroblast proliferation (125% cell viability). Combining with photothermal, NO-mediated antibacterial action, and ROS scavenging to alleviate oxidative stress, this antibiotic-free hydrogel dressing has great potential for clinical application for the treatment of refractory-infected wounds.