Study The Effects Of5-Aminolevulinic Acid Mediated Photodynamic Therapy For Skin Cancer Cells

The recent research progress on ALA mediated photodynamic therapy (ALA-PDT) and its clinical applications in dermatology was summarized. In order to provide the theoretical basis for improving of ALA-PDT efficacy and accelerating its clinical applications in dermatology, two human skin cancer cell lines-epidermal cancer cell A431and melanoma cell A375were used to investigate the effects of ALA-PDT. Fluorescence spectroscopy and laser scanning confocal microscopy were used to measure the fluorescence intensity and subcellular distribution of ALA induced PpIX in A431and A375cells, respectively. Morphological changes of A431and A375cells after ALA-PDT were observed with an inverted phase contrast microscope. The survival rate of A431and A375cells after ALA-PDT treatment was quantified with Cell Counting Kit-8colorimetric assay.The obtained results indicate that ALA induced PpIX content in cells increased with the incubation concentration of ALA and saturated at about0.6mM. After the cells incubated with0.6mM ALA, ALA induced PpIX fluorescence was observed inside the cells and also on the cytoplasm membrane under confocal microscopic images. No significant difference was found between A431and A375cells. Significant morphological changes of A431and A375cells were found after ALA-PDT. The survival rate of A431and A375cells dramatically decreased with the increasing of light dose for treatment. The survival rate decreased to less than25%at the light fluence of1.74J/cm. The sensitivity of A431cells to ALA-PDT was higher than that of A375cells. This findings suggest that ALA-PDT might be an effective treatment for skin cancers.