Effect of mixed-sulfonated aluminium phthalocyanine on human skin fibroblasts for photodynamic therapy

Abstract

Photodynamic therapy (PDT) can be defined as the combination of a light sensitive drug known as a photosensitizer and visible light of specific wavelength. PDT is carried out by administration of photosensitizer either systemically, locally, or topically to a tumor site followed after some time by the illumination of the tumor area with visible light, which, in the presence of tissue oxygen, leads to the generation of cytotoxic species and consequently to cell death and tumor destruction. The aim of the study was to evaluate the effect of mixed-sulfonated aluminium phthalocyanine (AlPcSmix) used as photosensitizers for PDT, determined by changes in cell morphology and cell viability of human skin fibroblasts (WS1). Methods. Cells incubated with 5, 10, 20 µg/ml AlPcSmix for 18hours were irradiated with 1 J/cm2 diode laser light, wavelength of 672 nm, output power of 5 mW/cm2, for 200s. Control groups were irradiated or incubated with a photosensitizer. Results. Changes in cell morphology were monitored using an inverted microscope and were digitally recorded. The effects of PDT were assessed using CellTiter Blue cell viability assay, which showed a significant reduction in viability for PDT treated cells compared to controls. Viability studies showed that the optimum phototoxic effect tested on WS1 cells was achieved in the combination of laser dose of 1 J/cm2 and AlPcSmix concentration of 10 µg/ml. Neither PDT drugs nor laser irradiation alone showed significant cytotoxicity or even morphologic alterations. Photoactivation of photosensitizers by visible light results in