Spectroscopic and biological studies of a novel synthetic chlorin derivative with prospects for use in PDT.

Photosensitizers with desirable combinations of chemical, photophysical and biological properties are essential for improving the efficacy of photodynamic therapy (PDT) against various cancers. Chlorins seem to be promising candidates for photodynamic therapy (PDT) owing to their photophysical properties. This paper reports spectroscopic and biological properties of a novel synthetic chlorin derivative. Cytotoxicity, phototoxicity as well as subcellular localization of the novel derivative was studied using Lewis lung carcinoma cultured cells (LLC). In the examined concentration range no significant cytotoxic effects were found but high phototoxicity was observed. Confocal laser scanning microscopy demonstrated that the compound, upon entering cells, was localized in the perinuclear cytoplasm of LLC cells. Using fluorescent microscopy we investigated the impact of PDT based on the novel compound upon cytoskeleton and DNA structure of LLC cells. Our results indicate that liposomes are effective in transferring the chlorin photosensitizer into the studied cells, leading to their high photosensitization, whereas the non-carrier delivery mode (i.e., DMSO) is rather useless for such purposes.