Synthesis and photodynamic antimicrobial activity of amphiphilic meso-arylporphyrins with pyridyl moieties

Abstract In this work we report on the synthesis of new cationic pyridyl-containing meso-arylporphyrins and their antimicrobial photodynamic activity against Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria in planktonic and biofilm modes of growth. Received compounds were characterized by EAS, fluorescence, 1H, 13C NMR spectroscopy, liquid chromatography and ESI-MS spectra. Their photophysical (absorbance and fluorescence), photochemical (singlet oxygen generation) properties dark and light-induced toxicity were studied. Aggregation behavior of PSs was investigated in the presence of nonionic solubilizers to identify the most effective nanocarrier. Pluronic F-127 polymer micelles appeared the most suitable nanocontainers for the cationic porphyrins solubilization. The structure/biological activity relationships were evaluated. The influence of aliphatic spacer length on the photochemical and biological properties of tetraphenylporphyrin derivatives was estimated. The inclusion of PSs in polymeric micelles of Pluronic F-127 noticeably increased their photodynamic activity. Our research showed that the proposed porphyrin macrocycle design offers strategies for the efficient photosensitizer modification in the field of antimicrobial photodynamic inactivation.