Evaluation of photodynamic therapy with Photodithazine in gliossarcoma treatment: in vitro study

Abstract

Gliosarcoma is an uncommon histopathological variant of glioblastoma multiforme, highly aggressive, and with unfavorable prognosis, reflecting a survival around months. The treatment consists of the application of surgical resection, radiotherapy, and chemotherapy, however, due to the difficulty of guaranteeing the complete elimination of the tumor and the extensive side effects, it is necessary to search for other alternatives. Photodynamic Therapy (PDT) shows itself as an innovative method by combining three fundamental components: photosensitizer (FS), light, and molecular oxygen. The interaction of light with FS accumulated in tumor cells will trigger a series of reactions with molecular oxygen, allowing the creation of reactive oxygen species, which interact with cellular components causing the death of the target cell. The objective of this project is to evaluate the cellular response of 9L/LacZ lineage of gliosarcoma cells when submitted to PDT treatment with chlorine Photodithazine (PDZ). For that, the PDZ will be used in serial concentrations of 200 ¼g/ml to 3,1 ¼g/ml with one hour of incubation. The light source will be a LED-based device (Biopdi / Irrad-Led 660) consisting of 54 LEDs, with 70mW of power in the 660nm region. The evaluation of the therapy will be carried out by localization of FS with confocal microscopy, genotoxic analysis of FS in the cell before and after irradiation, and cell viability by means of the trypan blue exclusion test, MTT and morphology in an optical microscope (Leica DM 2500).