MESO-TETRAPHENYLPORPHYRIN DIMER DERIVATIVE AS A POTENTIAL PHOTOSENSITIZER IN PHOTODYNAMIC THERAPY

Studies on the synthesis, preliminary irt vivo biological activity, si nglet oxygen and fluorescence yields of a dimeric porphyrin (DI) are d escribed. The pharmacokinetic behavior and photodynamic properties of the dimer D1 were examined in Balb/c mice bearing an MS-2 fibrosarcoma . Compound D1 shows a high selectivity for tumor localization (tumor/p eritumoral tissue ratios of dye concentration ranging between ca 100 a nd 140 at 24 h after drug administration of 5.0-1.0 mg kg(-1) into DL- alpha-dipalmitoylphosphatidylcholine liposomes). The phototherapeutic efficiency of dimer D1 was evaluated by following the growth curves of fibrosarcoma irradiated with red light (600-700 mm) with a total dose of 400 J cm(-2) at 24 h after intravenous injection. Photodynamic the rapy-treated tumors showed a significant delay in growth as compared t o untreated control mice. The results obtained suggest that the porphy rin dimer D1 may be a promising candidate for further use in PDT exper iments.