Conjugated Porphyrin Polymer With Superior Charge Transfer for Photodynamic-Immunomodulatory Prevention of CIED...

Diabetic patients face heightened risks for cardiac implantable electronic devices (CIED) infections. Herein, we developed a near-infrared (NIR)-activated porphyrin polymer (PTCPP) for photodynamic therapy of CIED infections, which achieves a 100% antibacterial rate with a 22% increase in anti-biofilm efficacy compared to porphyrin (TCPP) in vitro. In diabetic rats, a 93% bactericidal rate is further demonstrated by PTCPP, along with a 97% reduction in the levels of pro-inflammatory factors. It is found that singlet oxygen (¹O₂) and hydroxyl radicals (•OH) are the main reactive oxygen species (ROS), which can eliminate methicillin-resistant Staphylococcus aureus by disrupting mature biofilms. The immunomodulatory effect of PTCPP stems from dynamic regulation of macrophage polarization. Under irradiation, ROS induce M1 activation to eliminate pathogens, followed by metabolic reprogramming that promotes healing-conducive M2 polarization, thereby accelerating tissue repair. This work showcases the great potential of synergistic photodynamic-immunomodulatory strategies for the next-generation prevention of complex implant-related infections.