In vitro photodynamic therapy on melanoma cell lines with phthalocyanine

Photodynamic therapy (PDT) is a new treatment modality of tumours. The photochemical interactions of sensitizer, light, and molecular oxygen produce singlet oxygen and other forms of active oxygen, such as peroxide, hydroxyl radical and superoxid anion. Phthalocyanine ClAlPcS2, belonging among the promising second generation of sensitizers, was tested as an inducer of photodamage. We report the production of reactive oxygen species (ROS) and the phototoxicity of ClAlPcS2 assessed using G361 melanoma cells. A semiconductor laser (λ = 675 nm, output power 21 mW) was used as a source for evocation of the photodynamic effect. ROS generation and H2O2 release after PDT on G361 cells were detected using probe CM-H2DCFDA and recorded by luminescence spectrometer. Viability studies show, that the optimum phototoxic effect tested on G361 melanoma cells was determined in the combination of laser dose of 25 J cm−2 and phthalocyanine ClAlPcS2 concentration of 5 μg/ml. This combination of phthalocyanine concentration and corresponding radiation dose was lethal for melanoma cells.