3-Methylindole-substituted zinc phthalocyanines for photodynamic cancer therapy

Novel peripherally and non-peripherally 3-methylindole-substituted zinc phthalocyanine derivatives were synthesized as photosensitizers for photodynamic therapy in cancer treatment. The photophysical, photochemical and photobiological properties of targeted phthalocyanines were also investigated. For this purpose, the fluorescence and singlet oxygen quantum yields, and fluorescence lifetime values of the final compounds were determined in DMF solutions. The phototoxicity and cytotoxicity of the phthalocyanine complexes were tested against the invasive human breast cancer cell line (MDA-MB-231) for determination of their photosensitizing ability in the area of photodynamic therapy. It was revealed that while peripherally 3-methylindole-substituted phthalocyanine was found to be toxic for cells in both dark and light conditions, its non-peripherally substituted phthalocyanine analogue significantly caused cell death following light irradiation. A preliminary assay suggested that the non-peripherally linked phthalocyanine could be a suitable candidate for cancer treatment via photodynamic therapy techniques.