Single-Doped W₁₈O_49-x@Au-Embedded Dual-Network Silk Fibroin Hydrogel for NIR-Responsive Phototherapeutic Wound Healing

Bacterial infections remain a critical challenge in wound care, demanding advanced multifunctional materials for effective treatment. Here, this work presents a 3D-printable hydrogel (STFWA) integrating a Schottky heterojunction and dual-network architecture for synergistic photothermal and photodynamic antibacterial therapy. The hydrogel incorporates W18O49-x@Au nanostructures, where Au nanoparticles are in situ grown on oxygen-deficient W18O49-x (bandgap ≈1.5 eV), forming a Schottky junction that enhances carrier separation and reactive oxygen species (ROS) generation. The dual-network matrix, composed of silk fibroin and tannic acid-Fe3+ (TA/Fe3+), exhibits robust mechanical integrity and hemostatic capability, while silk fibroin enables high-resolution digital light processing (DLP) 3D printing. The co-existence of W18O49-x and Au induces dual localized surface plasmon resonance (LSPR), while TA/Fe3+ contributes to deep coloration, collectively boosting photothermal conversion. Upon near-infrared (NIR) irradiation, the hydrogel exhibits potent antibacterial efficacy against Staphylococcus aureus and Escherichia coli through combined photothermal and photodynamic mechanisms. In vivo studies using a rat model of infected wounds demonstrate accelerated healing, enhanced angiogenesis, and regulated inflammation. This work highlights a nanostructure-enabled hydrogel platform for NIR-activated, synergistic antibacterial therapy with clinical potential in infected wound management.