Magnesium phosphate mineralized Ce6 composite hydrogel with photodynamic therapy-mediated antibacterial, anti-inflammatory, and pro-angiogenic properties for application in infected wound healing.

Wound infection remains a significant clinical challenge, exacerbated by the growing prevalence of bacterial resistance due to the overuse of conventional antibiotics. Photodynamic therapy (PDT) offers a promising approach for wound sterilization that circumvents the issue of antibiotic resistance. However, conventional photosensitizers are prone to inactivation and exhibit poor retention at the wound site, limiting their clinical efficacy. To overcome these limitations, we developed a biomimetic mineralization approach to encapsulate the small-molecule photosensitizer chlorin e6 (Ce6) within magnesium phosphate nanoparticles (CMP NPs), preserving its photodynamic activity. This mineralized CMP NPs were further integrated with gelatin and natural moisturizing factor to fabricate a composite hydrogel dressing (CMP/Gel) for infected wound healing. Gelatin functions as a structural matrix that prolongs the local retention of CMP NPs, while the natural moisturizing factor enhances the hydration capacity and mechanical integrity of the dressing. Notably, magnesium ions released during the degradation of CMP NPs contribute to accelerated wound healing through multiple therapeutic effects, including antioxidant, anti-inflammatory, and pro-angiogenic activities following PDT-mediated bacterial eradication. Both