Household light source for potent photo-dynamic antimicrobial effect and wound healing in an infective animal model

Photodynamic antimicrobial chemotherapy (PACT) is considered a promising alternative to conventional antibiotic approach. We have previously developed a novel PS containing five lysine amino acids, pentalysine-β-carbonylphthalocyanine Zinc (ZnPc(Lys)₅), which in the presence of light, is highly toxic against a range of bacterial strains, including hospital isolated, drug resistant Acinetobacter baumannii. Here, we study the effect of light fluence of the two light sources on the PACT potency of ZnPc(Lys)₅. We observed that an exposure of E.coli to a red LED light for only 2 seconds (light fluence of 0.15 J/cm²) in the presence of ZnPc(Lys)₅ significantly eradicated 80% of the E.coli. We further demonstrated that a light fluence of 4.5 J/cm² from a household light source induced a noticeable photodynamic effect in vitro and in vivo animal model. This study points to a new research direction of reducing light illumination time by increasing potency of PS.