Injectable ROS-scavenging and NIR-responsive nanocomposite hydrogel for staphylococcus aureus-infected diabetic wound healing

Chronic diabetic wounds are often complicated by persistent infections and oxidative stress, which impede effective healing. In this study, we developed an injectable, dual-responsive nanocomposite hydrogel designed to simultaneously scavenge reactive oxygen species (ROS) and deliver photothermal and photodynamic therapy for wound treatment. The hydrogel was synthesized via dynamic boronate-ester crosslinking of poly(vinyl alcohol) (PVA) with a bis-boronic acid linker (TSPBA), enabling efficient ROS quenching. Incorporation of palygorskite/molybdenum disulfide (PGS/MoS₂) nanocomposites imparted photothermal and photodynamic properties, activated by NIR light. In vitro tests demonstrated that the PVA-TSPBA@PGS/MoS₂ hydrogel effectively scavenged ROS, induced mild hyperthermia (~ 48 °C) under NIR, and exhibited significant antibacterial activity against Staphylococcus aureus. In vivo, the hydrogel accelerated wound closure in a diabetic mouse model, with a 46.7% residual area at day 7, compared to higher residual areas in control groups (66.5-92.4%). By day 14, nearly complete wound healing was achieved, accompanied by reduced bacterial load and inflammatory markers, as well as enhanced re-epithelialization, angiogenesis, and collagen remodeling. These findings suggest that this multifunctional hydrogel represents a promising strategy for the treatment of infected diabetic wounds, offering a controlled, localized approach to wound healing.