Experimental photodynamic therapy with Zn(II)-naphthalocyanine compounds

Comparative photodynamic studies in hamsters bearing first generation transplanted rhabdomyosarcoma, injected with DPPC liposome incorporated Zn(III)-naphthalocyanine (ZnNc) or ZnNc-substituted compounds (ZnNc-amide, ZnNc-ether or ZnNc-amine) were carried out. A monochromatic irradiation at the absorption maximum for the corresponding compound (range 756-768 nm) by argon pumped LDS-571 day laser was applied. On the basis of changes of mean tumor diameter with time and tumor weight regression the photosensitizing effect appears to be the best one after ZnNc-amide application (even after using very low concentrations). The effect was very low at the unsubstituted ZnNc and there was no effect at all at the ZnNc-amine. In this case it is suggested that the phototherapeutic effect depends drastically on the substituent nature. (author). 6 refs., 1 fig., 1 tab