A Metal-Polyphenol Self-Assembled Coated 3D Sponge With Mild Photothermal Antibacterial, Exudate-Controlling, and...

Chronic wounds represent a prominent clinical challenge, often characterized by impaired healing due to uncontrolled bleeding, persistent bacterial infections, and an imbalanced inflammatory microenvironment. Herein, we report the design and fabrication of a bioinspired, multifunctional 3D nanofiber sponge (TB@CuPNS) armored with a copper-chelated polydopamine (PDA) coating and functionalized with thrombin (TB). Structurally, the porous sponge demonstrated excellent mechanical resilience, strong exudate absorption capacity, and rapid hemostatic efficiency, as validated in rat liver and femoral artery hemorrhage models. Functionally, the PDA coating imparts mild NIR-responsive photothermal properties (approximately 45°C) to the sponge, which worked synergistically with pH- and ROS-responsive copper ion release to deliver broad-spectrum antibacterial and antibiofilm effects through photothermal therapy (PTT) and chemodynamic therapy (CDT). Furthermore, copper ions and the PDA coating cooperatively scavenged excess reactive oxygen species (ROS) and modulated macrophage polarization from an M1 to an M2 phenotype. In an S. aureus-infected diabetic mouse wound model, TB@CuPNS under NIR irradiation significantly accelerated wound repair by stimulating angiogenesis, increasing collagen deposition, and alleviating chronic inflammation. This study provides an effective strategy for fabricating advanced biomaterials that actively regulate the complex biological cascades involved in wound repair.