Synergistic MS@Chl@Ag Composite System for Photothermal Antibacterial Therapy and Immune Microenvironment Modulation in Infected Wounds

Wound infection is a frequent and severe complication that provokes excessive inflammation, disrupts the wound microenvironment, suppresses proliferation and angiogenesis, and delays wound repair. To overcome these barriers, we developed an injectable MS@Chl@Ag (MSCA) therapeutic platform integrating antibacterial, immunomodulatory, and regenerative functions. Dextran microspheres were employed as carriers for silver nanoparticles biosynthesized by Chlorella (Chl@Ag). MSCA exploits silver nanoparticle-mediated photothermal therapy (PTT) for rapid bacterial eradication, while Chlorella releases bioactive factors that drive macrophage polarization toward an anti-inflammatory phenotype, thereby reshaping the immune microenvironment. In addition, the microspheres exhibit superior injectability and tissue adhesiveness, allowing sustained Chl@Ag release and providing a favorable three-dimensional scaffold that supports epithelial migration and neovascularization. With its multifunctional and controllable design, MSCA demonstrates a comprehensive strategy for infection-associated wound management, effectively integrating bactericidal activity with immune regulation and tissue regeneration.