Efeito de diferentes doses do laser de baixa intensidade sobre a viabilidade celular e o estresse oxidativo em células-tronco do ligamento periodontal

Abstract

Low-intensity laser therapy (LBI) is widely used in different areas of regenerative medicine, especially for its beneficial effects on cellular metabolism. In this study, the effects of LBI on cell viability and oxidative stress of periodontal ligament stem cells (PDLSCs) were evaluated. As PDLSCs were isolated the periodically extracted from human teeth. The cells then undergo a cell characterization process, through differentiation in adipogenic and osteogenic culture media, and also through analysis of stem cell surface markers in flow cytometry. After their acquisition and characterization, PDLSCs were maintained under cell growth conditions and divided into three groups: Group I (control); Group II (Laser 7.5 J/cm2) and Group III (Laser 22.5 J/cm2). The experiments were completed in quadruplicate and occurred in three time intervals (T0h, T24h and T48h). After the time intervals, the experimental tests were done to evaluate the cellular criteria. For the analysis of cell viability the MTT assay was used. The evaluation of reactive oxygen species was used as a dosage of malonaldehyde and glutathione. Preliminary results were positive as cells studied were positive for markers of mesenchymal stem cells and still differed in adipocytes and osteoblasts cell like. The results of the MTT assay were altered by Group III in relation to Group I in relation to Group II. The results of the MDA tests were significantly different in the intergroup interval at the time studied, but numerically the Group II presented as main means of absorbances. The differences between the experimental groups were not included in the GSH test. On the basis of the results concluded, irradiation with low intensity laser at higher doses (7.5 and 22.5 J/cm2) is not potentially inducing cell proliferation and that, after 48 hours of irradiation, a dose of 22.5 J/cm2 is applied to the cells of the PDLSCs system, but it is not possible, however, whether it is a deadly attack and is not significant in the release of reactive oxygen species.