An efficient formulation based on cationic porphyrins to photoinactivate Staphylococcus aureus and Escherichia coli.

AIM: Antibiotic resistance is an increasingly serious worldwide problem that needs to be addressed with alternative tools. Antimicrobial photodynamic therapy seems a promising approach but in some cases the synthesis of highly efficient photosensitizers requires laborious processes burdened by extensive chromatographic purifications. In this study, we evaluate the suitability of a formulation (Form-1) containing porphyrins bearing different charges, obtained during the synthesis of the highly efficient photosensitizer 5,10,15-tris(1-methylpyridinium-4-yl)-20-(pentafluorophenyl)porphyrin tri-iodide.

RESULTS: Form-1 was equally effective in the photoinactivation of Escherichia coli and Staphylococcus aureus (reductions >5 log) as the best stand-alone photosensitizer.

CONCLUSION: The effective reduction of bacteria with Form-1 provided promising indications supporting its use, leading to a substantial decrease in costs and production time.