Efeitos da radiação ultravioleta de banda C (254nm) sobre uma linhagem de fibroblastos da mucosa oral humana

Abstract

Devices as a source of UV-C radiation emission arouse great interest for the disinfection of various environments, such as water treatment plants and hospital environments, being a promising approach to reduce the microbial load in the air, environment and surfaces. Therefore, the search for alternatives in the construction of low-cost and easy-to-operate devices aimed at disinfecting hospital environments becomes essential to minimize the number of deaths caused by hospital infections. In this context, the effects of UV-C radiation have been reported in the literature with several harmful activities.Nonetheless, the effects with the use of a physical barrier have not yet been described, as well as the effects on non-tumor human fibroblasts of the oral mucosa. Thus, the aim of this study was to investigate the effects of 254 nm UV-C radiation emitted by a low-cost portable luminaire in an oral mucosal fibroblast (FGH) cell line and to investigate the protective effects of physical barrier materials of personal protective equipment (PPE). After standardization of the irradiation protocol, the cells were exposed to UV-C radiation (254 nm, 18 W, 13 mJ/cm2) for 10 seconds, and after 1, 6, 24 and 72 hours, analyses were performed in relation to their viability, morphology and cell death by fluorescence. The results indicated a significant reduction in time-dependent cell viability, correlated with changes in cell morphology, especially at 72 hours after exposure. Corroborating these findings, greater labeling with OA/PI fluorescent dyes was observed in cells exposed to radiation, indicating the occurrence of apoptosis and necrosis, especially at 24 and 72 hours, including cellular nuclear alterations, with the presence of ADN fragmentation and condensation.Nevertheless,when using latex materials (rubber gloves component) and polypropylene (PFF2 disposable mask) as a barrier between the cells and a radiation source for 300 seconds, there was protection against cell viability, going from a reduction of about 80% in cells exposed without barrier, to 20 and 25% when latex and polypropylene were used, respectively. The same protection was observed when analyzing cell morphology and discrete OA/PI staining. Therefore, it is suggested that the damage caused to FGH cells is similar to that observed in other cell types, and that the use of materials present in PPE shows promise in protecting cell damage in case of accidental exposure. However, further studies are needed to confirm the protective effect and its mechanisms, as well as the resistance of the materials that compose PPE to radiation.