Avaliação fotodinâmica em células tumorais do câncer de mama e fibroblasto utilizando o fotossensibilizador bacterioclorina – trisma

Abstract

Breast cancer is one of the main health problems among women. It is the first cancer in incidence and the second in the number of deaths. This type of tumor presents a high degree of recurrence due to failures in the treatment and the occurrence of metastasis which t is the leading cause of death. Photodynamic therapy appears as a promising therapeutic alternative, which can be used to treat various types of tumors. This technique uses light, which stimulates the photosensitizer and provides the formation of reactive oxygen species, causing irreversible damage to cells and cell death. The goal of this work was to evaluate in vitro the efficacy of a new photosensitizer (FS) of bacteriochlorin class, bacteriochlorin - trism, using photodynamic therapy in tumor cells. To perform the photodynamic therapy were used seven different doses of the photosensitizer: 0.01 μM, 0.1μM, 0.5 μM, 1.0μM, 2.5μM, 5.0μM, and 10μM, and three different light doses 2, 7, and 15 J.cm-2. Cell viability tests, flow cytometry, and confocal microscopy were performed to evaluate cell death and cytotoxic activity of bacteriochlorin - trism in cells. Concentrations from 0.5 μM showed 80% cell death independent of the light doses used. In the colocalization study, the highest similarity with lysosome was found, and in cytometry, it was shown that the type of cell death was by apoptosis. The best parameters for photodynamic therapy were observed against breast cancer cells (MCF-7 strain). The photosensitizer bacteriochlorin - trism demonstrated good results enabling future efficient protocols of photodynamic therapy against MCF - 7 type tumoral lineage.