Imaging and detection of cell apoptosis byIn vitrophotodynamic therapy applications of zinc (II) phthalocyanine on human melanoma cancer.

This study aims to investigate the photodynamic therapy (PDT) effects on MeWo (human melanoma cells) and HaCaT (normal human keratinocyte cells) by light stimulation of different concentrations of Zinc (II)-tetra-tert-butyl-phthalocyaninato (ZnPc). MTT viability assay data indicated that a 25 μM concentration of ZnPc is cytotoxic to the melanoma cancer cells while this concentration of ZnPc is not cytotoxic for the HaCaT cell line. Moreover, the results showed that photoactivated ZnPc at 12.5 μM concentration reduced the cell viability of the MeWo cell line to about 50 %. At this photosensitizing concentration, the efficacy of light doses of 20, 30, 40, and 50 J/cm2 was evaluated against MeWo and HaCaT cells. ZnPc at a concentration of 12.5 μM activated with a light dose of 50 J/cm2 was the most efficient for the killing of MeWo cells. In conclusion, the 12.5 μM of ZnPc with the treatment light dose of 50 J/cm2 from a RED light source was adequate to destroy MeWo cells by the ROS-induced apoptosis mechanism. It also exhibited low killing effects on healthy HaCaT cells. These findings are supported by the results of apoptosis with the Annexin V & Dead Cell Kit and fluorescence imaging.