Heterojunction-Enhanced Photodynamic Uterine Scaffold Mediated by Upconversion for Treating Infectious Injuries
Bacterial infection following endometrial injury delays tissue regeneration and may progress to endometritis and other reproductive disorders. Photodynamic therapy (PDT) offers a promising antibacterial strategy in the post-antibiotic era, yet its efficacy is often limited by rapid recombination of photogenerated charge carriers and poor penetration of visible excitation light. Here, we report a previously unexplored upconversion-mediated, Type I dominant photodynamic antibacterial uterine scaffold specifically designed for infection-associated endometrial injury. The core innovation is the construction of a Schottky Ag0-Ag2S heterojunction on NaYF4:Yb,Tm nanoparticles using ZIF-8 as a sacrificial precursor, enabling efficient charge separation and oxygen-independent hydroxyl radical generation, overcoming the oxygen dependence of conventional Type II PDT under hypoxic uterine conditions. The upconversion core permits deep-tissue-penetrable near-infrared (NIR) activation. Beyond instantaneous PDT, dynamic release of Ag+ ions provides synergistic bactericidal activity, enabling spatiotemporally coordinated biofilm disruption. These nanostructures were incorporated into patient-customizable, biodegradable poly(L-lactic acid) (PLLA) scaffolds fabricated by selective laser sintering, achieving simultaneous antibacterial therapy and endometrial regeneration in a single platform. This integration of an oxygen-independent PDT mechanism, MOF-templated heterojunction engineering, and 3D printed personalized uterine implants constitutes a comprehensive therapeutic strategy not previously reported for treating infection and endometrial injury.