A Near-Infrared-Triggered Photothermal/Nitric Oxide-Enhanced Photodynamic Nanoplatform Based on l-Arginine-Modified MPDA for Synergistic Diabetic Wound Healing.

Diabetic wounds, plagued by hyperglycemia, bacterial infections, and chronic inflammation, pose a global challenge. Herein, an intelligent photothermal-responsive nanoplatform (AI-MPDA@BP) was constructed by modifying polydopamine (MPDA) with l-arginine (l-Arg), then loading indocyanine green (ICG) and black phosphorus (BP) nanosheets. Under near-infrared light (NIR) irradiation, it generates efficient photothermal therapy (PTT) and reactive oxygen species (ROS), which trigger sustained NO release from l-Arg. NO not only exerts antibacterial activity but also boosts ICG-mediated photodynamic therapy (PDT). Meanwhile, BP's antioxidant properties enable robust ROS scavenging. The PTT-PDT synergy neutralizes oxidative stress and alleviates inflammation, achieving a 95% bactericidal rate against Staphylococcus aureus (S. aureus). In diabetic mouse models, AI-MPDA@BP eliminated infections, reversed inflammation, and promoted angiogenesis and collagen deposition, enabling scar-free complete wound healing within 14 days. This multifunctional nanoplatform offers an efficient, safe strategy for chronic wound treatment with broad clinical prospects.