0,15-BIS(2-METHOXY-4-SULFOPHENYL)-21-THIAPORPHYRIN AS A NEW POTENT SENSITIZER IN PHOTODYNAMIC THERAPY

The main purpose of the study was to investigate the effectiveness of a new photosensitizer for photodynamic therapy, phophenyl)-10,15-bis(2 -methoxy-4-sulphophenyl)-21- thiaporphyrin (21-thiaporphyrin) was comp ared to chlorin e(6) and tetra(m-hydroxyphenyl)porphyrin (m-THPP) for its ability to sensitize tumors and skin to light, Chlorin e(6) and m- THPP induced a strong tumor and skin photosensitization. In contrast, the same doses of 21-thiaporphyrin produced no skin sensitization and gave approximately 10 mm tumor necrosis after light exposure, in compa rison to the 5-6 mm necrosis induced by chlorin es or m-THPP under ide ntical conditions. 21-Thiaporphyrin, tested as a potential photosensit izer, induced no skin sensitization even at doses as high as 7.5 mg/kg body weight, 21-Thiaporphyrin presents a high potency in tumor sensit izing, i.e. a feature required for an efficient photosensitizer in pho todynamic therapy applications.