A mitochondria-targeted zinc(ii) phthalocyanine for photodynamic therapy

Abstract

A water-soluble zinc(II) phthalocyanine (ZnPc1) substituted with 1-(3-methyl) imidazoliumylethyloxy on the periphery was synthesized, and its subcellular localization and photodynamic activities were studied. ZnPc1 exhibited an almost exclusive mitochondrial-localizing property in human cervical carcinoma (HeLa) cells. Remarkable photocytotoxicity but low dark cytotoxic properties were observed for ZnPc1 in four different cancer cell lines. Photodynamic treatment (PDT) with ZnPc1 resulted in the generation of reactive oxygen species, a collapse of the mitochondrial membrane potential and chromatin condensation, all important hallmarks of apoptosis. The results are consistent with its mitochondrial localization property and qualify ZnPc1 as a promising PDT agent.