New sulfonamide and sulfonic ester porphyrins as sensitizers for photodynamic therapy

Abstract

New sulfonamide and sulfonic ester porphyrins were prepared and their in vitro characteristics as sensitizers for photodynamic therapy were assessed. Fluorescence spectra were characterised by two main peaks, located between 650-680 nm and 705-740 nm, respectively. Some of these new porphyrins (three out of nine) showed good photodynamic properties in the in vitro assays. In the absence of light, these porphyrins are not toxic. With 50 J.cm−2 illumination light (514 nm) they induced mortality in 50% of HT29 cells with 2 to 4.5 μg/ml. Comparison of in vitro phototoxic efficacy of these three compounds with other photosensitizers already described confirms interest in their phototoxic properties.