pH-Responsive Metal-Phenolic Network Nanoparticles for Synergistic Chemo-Photodynamic Antibacterial Therapy

The emergence of drug-resistant bacteria and their easy recurrence have been challenging in the clinical treatment of skin abscesses. Therefore, there is an urgent need to develop treatments against bacterial infections. This study developed an antibacterial PDT/CDT dual-mode treatment platform (Ce6/TA-Fe3+ NPs) to treat subcutaneous abscesses and promote wound healing. The Ce6/TA-Fe3+ NPs can quickly generate 1O2 under illumination and ·OH through the Fenton reaction in the microenvironment, leading to the eradication of biofilms. In particular, the Ce6/TA-Fe3+ NPs demonstrated over 90% effectiveness in fighting Staphylococcus aureus (S. aureus) bacteria and successfully eliminated biofilms after being exposed to a 660 nm laser for 10 min. Antibacterial mechanism research showed that the Ce6/TA-Fe3+ NPs induced a speedy rupture of the bacterial cell membranes, membrane lipid peroxidation, protein leakage, inhibition of intracellular ATP, and DNA damage based on the synergistic effect of PDT and CDT. Meanwhile, the Ce6/TA-Fe3+ NPs demonstrated good biosafety to normal cells and can clear the bacteria from the infected wound to promote the healing process of the infected area. The experimental results in vivo demonstrated that Ce6/TA-Fe3+ NPs effectively treated skin abscesses. Therefore, this study suggested that the Ce6/TA-Fe3+ NPs possessed the ability to kill bacteria, eliminate biofilms, and effectively treat subcutaneous abscesses based on the synergistic mechanism of PDT and CDT, which provided the promising strategy for the antibacterial medication and treatment of subcutaneous abscesses.