Photodynamic Antibacterial Effects Of A Phthalocyanine-based Photosensitizer On Multidrug-resistant Bacterial Infection

Bacterial skin and soft tissue infections are abundant worldwide.The rise in the incidence of multidrug-resistant(MDR)bacterial infections has made the need for alternative means of treatment more pressing.We herein report a zinc phthalocyanine derivative,pentalysine β-carbonylphthalocyanine zinc(ZnPc-(Lys)5)and its strong capability of killing nosocomial MDR bacteria,including MDR-Escherichia coli and MDR-Acinetobacter baumannii.In in vitro studies,we observed that ZnPc-(Lys)5 in micromolar concentrations killed above MDR bacteria in 6-6.5 log10 orders with only 5-minute illumination of red light at a dosage of 12.75 J/cm2).Further in vivo studies on a mouse infection model demonstrated that ZnPc-(Lys)5 efficiently inhibited the MDR bacterial growth after one-time photodynamic antibacterial therapy and,interestingly,significantly accelerated the wound healing.Putting together,our findings establish ZnPc-(Lys)5 as a potent antimicrobial candidate for the clinical test on localized infection.