In vitro photodynamic effect by phthalocyanine in A549 cell line

Photodynamic therapy (PDT) utilizes a combination of sensitizer, visible light and molecular oxygen to generate singlet oxygen and reactive oxygen species (ROS) such as hydrogen peroxide, hydroxyl radical and superoxid anion. Photochemical reactions lead to damage and destruction of cancer cells. The most suitable and effective source of radiation used in PDT is a laser. For this study, a semiconductor laser with output power of 50 mW and 675 mn was selected. In this paper we report a generation of ROS using chloroaluminium disulphonated phthalocyanine (ClAlPcS2) in A549 bronchogenic carcinoma cell line after PDT in vitro. Phthalocyanines, belonging to a new generation of substances for PDT, exhibit effective tissue penetration because of their proper light absorption region, chemical stability and photodynamic stability. The fluorescence measurement with molecular probes, CM-H(2)DCFDA and Amplex Red, was performed for detection of ROS generation and hydrogen peroxide release from cells. Our results demonstrated, that irradiation of cells by laser dose of 10 J.cm(-2) induces higher rates of fluorescence in cells loaded with phthalocyanine compared to 20 J.cm(-2). Furthermore, the production of ROS increases up to sensitizer concentration of 10 mu M. The highest ROS generation was observed at laser dose of 10 J.cm(-2) and 10 mu M ClAlPcS2. The rates of fluorescence for hydrogen peroxid measurements were almost identical with all chosen concentrations at laser doses of 10 and 20 J.cm(-2).