Boron dipyrromethene fungicide for anti-microbial photodynamic therapeutics

Abstract

Due to inadequate light transmission into the subsurface, one of the key challenges for conventional photodynamic therapy (PDT) is realizing successful treatment of deep-skin pathogenetic bacterial infectious wounds. Preparation of near-infrared (NIR) photosensitizers (PSs) with potent antibacterial activity is a potential solution to address this issue. In the present work, a boron dipyrromethene (BDP) derivative was synthesized, which had red light absorption and NIR fluorescence. Under 635 nm of irradiation, BDP could generate massive reactive oxygen species (ROS) for sterilization, which exhibited robust photodynamic antiseptic property against Gram-positive bacteria (S. aureus), with a minimum inhibitory concentration of only 240 nM (140 mW cm ⁻²). More importantly, BDP was capable of efficiently suppressing the development of bacterial biofilms and even eliminate established biofilms, thereby facilitating the enhancement of sterilizing efficacy. Furthermore, the promising antibacterial capability of BDP was validated in the treatment of S. aureus-infected abscess. The present work presents an antibiotic-free strategy for highly effective light-triggered abscess therapy.