Investigation of powerful fungicidal activity of tetra-cationic platinum(II) and palladium(II) porphyrins by antimicrobial photodynamic therapy assays

•Application of positively charged porphyrins against fungi.•Use of cationic porphyrins to treat dermatophytosis.•3PtP tetra-cationic porphyrins are highly effective in photoinactivating dermatophyte fungi. [Display omitted] This manuscript reports enhanced antimicrobial photoinactivation using tetra-cationic porphyrins with peripheral platinum(II) and palladium(II) complexes against fungal dermatophyte strains. Six different positively charged porphyrins were used and applied in antimicrobial photodynamic therapy experiments (aPDT) against dermatophyte fungi colonies. The microbiological tests were conducted with an adequate concentration of photosensitizer (PS) under white-light irradiation for 120 min and the most effective PS meta isomer 3PtP significantly reduced the concentration of viable fungal colony. In this way, tetra-cationic porphyrins containing platinum(II)-bipyridyl complexes may be promising fungicidal aPDT agents with potential applications in future clinical cases.