An experimental study on photosensitization of human liver cancer cells with sulfonated aluminum phthalocyanine (ALSPC)

The photosensitizing effect of sulfonated aluminum phthalocyanine to human liver cancer cells was studied by determining the kinetics of its cellular uptake, its state of aggregation therein and its photocytotoxicitic effect on these cells. Fluorescence methods were used to measure the cellular uptake in cell extracts and intact cells in monolayer. Results exhibited that the cellular uptake increases with the incubation time of ALSPC and saturates at 24 hrs. This relation was in coincidence with that between ALSPC's photocytotoxic effect and the ALSPC incubation time. Although the average ALSPC concentration in cells is higher than the incubation concentration of ALSPC, laser fluorescence, experiments showed that the fluorescence peak of ALSPC in cells incubated in higher concentration coincides with that of its aqueous solution of low concentration, suggesting that ALSPC in cancer cells exists in monomer state. Characteristics of the photodamaging effect of ALSPC to cancer cells were studied by both the method of typen blue staining and that of isotope labeling, which showed similar results. Results of the isotope labeling experiments implies that the DNA is damaged in ALSPC photosensitization. The photodamage on cells was also studied with 3 T 3 mouse cells (conversion), showing agreeable results to that with liver cancer cells, which suggests that ALSPC's photocytotoxic effect is nonselective to cell types.