Abstract

In this paper the cytotoxic effect of m-THPC, Foscan^®, as well as of the liposomal formulation of m-THPC, Fospeg^®, (kind offer of Biolitec) were studied post PDT in the human prostate cancer cell line LNCaP. The cells were incubated for 24h with 0.15 μg/ml and 1.2 μg/ml Foscan^® and Fospeg^®. Irradiation was performed with a 652nm laser and energy doses 180, 360 and 540mJ/cm². The effect was assessed by the MTT viability test 24h after irradiation. Also the intracellular localization of Foscan^® and Fospeg^® was monitored by using Laser Scanning Confocal Microscopy Imaging. The results showed no dark toxicity either with Foscan^® or Fospeg^® at any concentration. Also irradiation at each energy dose in the absence of any photosensitizer, did not affect cellular viability. The cellular death caused after Photodynamic Treatment was dependent on m-THPC concentration and formulation, as well as the delivered energy dose. Fospeg^® was more effective as LD₅₀ was achieved with 0.15μg/ml at 180mJ/cm² while for the same cytotoxic result 1.2μg/ml Foscan^® was needed. Images from confocal microscopy revealed higher fluorescence intensity in the cytoplasm after incubation with Fospeg^®, than upon incubation with Foscan^® under the same experimental conditions.

© 2009 OSA/SPIE