NIR-Light-Activable Macrophage Polarization Orchestration Using Laser-Structured Janus Nanoplatform Derived from Waste for Infected Wound Healing.

Abstract

The human skin is highly susceptible to bacterial infections and inflammation when its integrity is disrupted. Treatment of infected wounds is a big challenge in modern medicine, and rising antibiotic resistance motivates the development of antibiotic-free therapies. Here, we present a stimuli-responsive wound dressing that integrates carboxylated eggshell membrane (ESM) with electrosprayed tannic acid/iron (TAFe) particles trapped between electrospun Poly-L-lactide-caprolactone (PLCL) layers and precisely laser-structured to increase porosity and fit the wound size. The TAFe exhibits stable photothermal conversion and antioxidant activity, eradicating more than 99.5% of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), while maintaining high biocompatibility in vitro. In an infected rat model, the sandwich-like ESMmod/PLCL/TAFe dressing accelerated closure and achieved near-complete healing, with residual wound area <1% by day 14. Analysis shows that the material promotes M2-mediated reparative microenvironment, which, in consequence, suppresses TNFα and IL-6, a pro-inflammatory cytokines, and enhances angiogenesis through increased CD31 and VEGF levels. Moreover, a more organized collagen structure and less scarring were found in the wound bed. Importantly, the material is partially derived from waste, aligning with circular economy principles and reducing resource burden. The versatile composite offers an antibiotic-free strategy that disinfects, modulates inflammation, and promotes regeneration of infected wounds.