Lipid vesicle-loaded meso-substituted chlorins of high in vitro antimicrobial photodynamic activity†
Photodynamic inactivation potential against bacteria of four chlorin derivatives with phenyl or fluorophenyl substituents was evaluated. The quantum yield values of singlet oxygen formation were in the range of 0.16–0.86. Compounds were characterized by high quantum yields of fluorescence (0.15–0.44) and moderate photostability in DMF solutions. Irradiation of chlorins in DMSO resulted in their phototransformation and then photodecomposition. Photodynamic inactivation of bacteria was performed after the compounds had been loaded into lipid vesicles. The following log reductions of growth values were obtained: Enterococcus faecalis >5.44; Staphylococcus aureus 2.74–5.34; Escherichia coli 0.01–2.14. No activity of meso-substituted chlorins was noticed against Pseudomonas aeruginosa and fungi Candida albicans and Trichophyton mentagrophytes.