In Vitro and In Vivo Photosensitizing Applications of Photofrin in Malignant Melanoma Cells

Background: The object of the present study was to evaluate the feasibility of photodynamictherapy (PDT) for malignant melanomas through in vivo and in vitroprocesses.Methods: Photofrin (porfimer sodium) was evaluated through in vitro processes withhuman malignant melanoma cells (MMCs). The in vitro absorption and photosensitizingactivity of Photofrin was examined in an MMC culture system.The in vivo biological activity of Photofrin applied to subcutaneous implantedmelanoma (SIM) in nude mice and exposed to different total light dosagesat 630 nm was studied by determining the destruction of the tumors.Subcelluar localization and binding were observed under a fluorescent confocalmicroscope.Results: MMCs incubated with Photofrin at a concentration of about 3.5 μg/ml andexposed to laser light at 630 nm with a power density of 100 mW/cm2,showed 50% cell killing. An electron microscopic study demonstrated significantdestruction of the target after PDT.Conclusion: Detection of the photosensitizer Photofrin was localized and its distributionfully observed. PDT-Photofrin has the capability to destroy MMCs throughin vitro and in vivo SIM treatment.