Antimicrobial Nanocomposite for Photodynamic Therapy with Trojan Horse Effect

Bacterial antibiotic resistance poses a global threat to public health, highlighting the urgent need for innovative antimicrobial strategies. Zinc-based nanomaterials have shown promise in antibacterial treatments but are often limited by their low antimicrobial efficiency and poor biocompatibility. In this study, we propose a synergistic antibacterial approach that utilizes the Trojan horse effect through nanocomposites. By exploiting bacterial dependence on Fe3+, we introduce Ga3+ as a substitute, disrupting bacterial growth from within. Utilizing a ZIF-L carrier to load indocyanine green (ICG), we achieve targeted delivery of ICG, which generates ROS under light irradiation, effectively eradicating methicillin-resistant Staphylococcus aureus biofilms. In addition, the combined application of Zn2+ and Ga3+ effectively inhibits the growth of Porphyromonas gingivalis, providing complementary synergistic damage to bacteria from the inside out. This combined approach, integrating Zn2+, the Trojan horse mechanism, and photodynamic therapy, offers a promising therapeutic strategy against bacterial antibiotic resistance.