Efeito do nanomaterial de óxido de grafeno (GO) de interesse da indústria petrolífera: in vitro e in vivo

Abstract

Graphene oxide (GO) is a two-dimensional nanomaterial derived from graphite, functionalized with oxygen-containing groups that confer hydrophilic properties and surface reactivity, enabling a wide range of industrial applications. However, expanding its use requires a better understanding of its biological effects and potential health risks. This study aimed to evaluate the nanotoxicity of GO developed for enhanced oil recovery, considering its physicochemical properties and biological responses in experimental models. GO was characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, dynamic light scattering, zeta potential, and scanning electron microscopy. The results confirmed the presence of characteristic oxygen-containing functional groups and demonstrated dispersion medium-dependent behavior, with greater colloidal stability in ultrapure water than in saline solution (0.9%) or DMEM, and mean equivalent circular diameters of 11.37 μm in water and 11.78 μm in DMEM. In vitro, HepG2 cells exposed to GO (100-500 μg/mL) showed a transient increase in mitochondrial metabolic activity, suggesting adaptive cellular responses. In vivo, BALB/c mice were exposed via intraperitoneal administration at doses ranging from 5 to 50 mg/kg. Transient reductions in food and water intake and body weight were observed, accompanied by changes in the leukocyte profile. These changes included increased neutrophils and decreased total leukocytes, mononuclear cells, and eosinophils in peritoneal cavity lavage, as well as elevated neutrophil counts in bronchoalveolar lavage. Among the cytokines evaluated (IL-6, IFN-γ, and TNF), only IL-6 showed a significant reduction in peritoneal cavity lavage. An increase in relative liver weight associated with GO accumulation, elevated serum aspartate aminotransferase levels, and histopathological alterations in the liver, spleen, and lungs characterized by inflammatory infiltrates were also observed. These findings suggest that GO may induce mild local inflammatory responses and dose-dependent hepatic accumulation, highlighting the importance of further studies with prolonged exposure to assess potential adverse effects over time and to investigate the reversibility of the observed biological responses.