Photodynamic properties of a novel cationic chlorin derivative in solution and in human red blood cells

DARIO D. FERREYRA, MARIANA B SPESIA, M. ELISA MILANESIO, EDGARDO N. DURANTINI

Encuentro; XI Encuentro Latinoamericano de Fotoquimica y Fotobiologia; 2012

Photodynamic therapy is a promising cancer treatment which involves a combination of visible light and a photosensitizer. Recent synthetic activity has led to a great number of potential photosensitizers and among them chlorins are one of the most promising candidates. In chlorin-type photosensitizers the red-shifted absorption band (lmax~650 nm, e>104 M-1cm-1) allows for deeper light penetration into tissue than in the case of porphyrin type compounds. The excitation coefficient of chlorins is about ten times higher than that of the corresponding porphyrins. Furthermore, they seem to be highly efficient singlet molecular oxygen, O2(1Äg), generators. Such photophysical properties fulfil the requirements for a good photosensitizer and make chlorins promising candidates for applications in PDT. In this work, meso-tetrakis(9-ethyl-9-methyl-3-carbazoyl)chlorin (Chlor) was synthesized by the reduction of the corresponding porphyrin (Por) using diimide.