Comparison of Ti:sapphire laser and excimer-laser-pumped dye laser for PDT with Zn(II)-phthalocyanine

摘要

Abstract: We compared the photodynamic efficiency of pulsed to cwlaser irradiation in a cell culture experiment with aNIH ovarian cancer cell line (NIH-OVCAR3). Ourphotosensitizer was a cationic Zn(II)-phthalocyaninewith an absorption maximum near 675 nm. The lasersystems we use are an excimer laser pumped DCM-dyelaser ($tau $EQ 15 ns) and a cw Ti:sapphire laser. Thephotodynamic activity of the photosensitizer stronglydepends on the pulse fluence and decreases withincreasing fluence due to saturation of the sensitizer.In another experiment no changes in the lightpenetration depth into the tissue for pulsedirradiation could be detected up to a pulse intensityof 3 MW/cm$+2$/. !9