[Evaluation of Photo- and Cytotoxicity of Chlorin e6 Ester Derivatives and Their Liposomal Forms].

Photophysical characteristics and photosensitizing activity of the chlorin e6 dimethyl and trimethyl ester derivatives in various solution and their liposomal forms were studied. It was shown that in lipid vesicles chlorin e6 ester derivatives are predominantly in the monomeric state and possess optimal photophysical properties and high photochemical activity. The rate of redistribution of the chlorin e6 dimethyl ester from lipid vesicle to cells was higher as compared with that one of the chlorin e6 trimethyl ester. The increase of the serum concentration in the incubation medium has a different effect on processes of accumulation of the liposomal forms of the chlorin e6 dimethyl and trimethyl ester derivatives by the cells. Cell culture studies showed that application of liposomal forms of the chlorin e6 dimethyl and trimethyl ester derivatives significantly decreases their cytotoxicity but keeps high cytotoxic effect of photodynamic activity of the chlorin e6 ester derivatives.