A novel tricationic fullerene C60 as broad-spectrum antimicrobial photosensitizer: mechanisms of action and potentiation with potassium iodide

AGAZZI, MAXIMILIANO L.; DURANTINI, JAVIER E.; QUIROGA, EZEQUIEL D.; ALVAREZ, M. GABRIELA; DURANTINI, EDGARDO N.

Photochemical and Photobiological Sciences

ROYAL SOC CHEMISTRY

Año: 2021

1474-905X

A novel amphiphilic photosensitizing agent based on a tricationic fullerene C60 (DMC603+) was efficiently synthesized from its non-charged analogue MMC60. These fullerenes presented strong UV absorptions, with a broad range of less intense absorption up to 710 nm. Both compounds showed low fluorescence emission and were able to photosensitize the production of reactive oxygen species. Furthermore, photodecomposition of l-tryptophan sensitized by both fullerenes indicated an involvement of type II pathway. DMC60 3+ was an effective agent to produce the photodynamic inactivation (PDI) of Staphylococcus aureus, Escherichia coli and Candida albicans. Mechanistic insight indicated that the photodynamic action sensitized by DMC60 3+ was mainly mediated by both photoprocesses in bacteria, while a greater preponderance of the type II pathway was found in C. albicans. In presence of potassium iodide, a potentiation of PDI was observed due to the formation of reactive iodine species. Therefore, the amphiphilic DMC60 3+ can be used as an effective potential broad-spectrum antimicrobial photosensitizer.