Exploring graphene-based materials’ genotoxicity: inputs of a screening method

Abstract

Graphene-based materials (GBMs) are promising nanomaterials, and several innovations depend on their use. However, the assessment of their potential hazard must be carefully explored before entering any market. GBMs are indeed well-known to induce various biological impacts, including oxidative stress, which can potentially lead to DNA damage. Genotoxicity is a major endpoint for hazard assessment and has been explored for GBMs, but the available literature shows conflicting results. In this study, we assessed the genotoxicity of 13 various GBMs, one carbon black and one amorphous silica through a DNA damage response assay (using a human respiratory cell model, BEAS-2B).Concurrently, oxidative stress was assessed through a ROS production quantification (DCFH-DA assay using a murine macrophage model, RAW 264.7). We also performed a full physicochemical characterization of our samples to explore potential structureactivity relationships involving genotoxicity. We observed that surface oxidation appears linked to genotoxicity response and were able to distinguish several groups within our studied GBMs showing different genotoxicity results. Our findings highlight the necessity to individually consider each nanoform of GBMs since the tested samples showed various results and modes of action. We propose this study as a genotoxicity assessment using a high-throughput screening method and suggest few hypotheses concerning the genotoxicity mode of action of GBMs.

Environmental and Health Impacts of Graphene and Other Two-Dimensional Materials: A Graphene Flagship Perspective

“…In a different study, the genotoxicity of a wide range of GBMs (13 types of GNPs and rGO of various sizes) was tested in submerged normal human broncho-epithelial BEAS-2B cells. 287 For rGO, 3 out of 7 materials did not induce genotoxicity even at the highest dose (100 μg/cm 2 ). In contrast, all 6 tested GNPs induced genotoxicity at 6 h. The extent of surface oxygen content leading to ROS production was identified as one of the main drivers of genotoxicity.…”

“…All materials induced significant primary-indirect genotoxicity in monocultured TT1 cells, and secondary genotoxicity in the form of oxidative stress in the TT1/THP-1 coculture model. In a different study, the genotoxicity of a wide range of GBMs (13 types of GNPs and rGO of various sizes) was tested in submerged normal human broncho-epithelial BEAS-2B cells . For rGO, 3 out of 7 materials did not induce genotoxicity even at the highest dose (100 μg/cm 2 ).…”

Experimental and Computational Nanotoxicology—Complementary Approaches for Nanomaterial Hazard Assessment

“…Primary genotoxicity can be distinguished from secondary genotoxicity: primary genotoxicity is defined as genetic damage induced by nanomaterials themselves, whereas in secondary genotoxicity, nanomaterials do not interact directly with the target cell but produce an inflammatory response in neighboring cells, resulting in the oxidative damage of DNA by ROS. Please note that primary genotoxicity can also be mediated by ROS formation formed in cells by the interaction of nanomaterials, e.g., with mitochondria [13,57]. To assess genotoxicity, different markers can be used evaluating DNA damage, gene mutations, and chromosomal damage [21].…”

“…For instance, the human hepatoma HepaRG cell line was treated with a large set of nanomaterials, coatings, and supernatants at different concentrations, and 14 different biological endpoints (including viable cell count, cell membrane permeability, apoptotic cell death, mitochondrial membrane potential, and steatosis) were analyzed using HTS [140]. The HTS method was also used to assess the genotoxicity induced by different graphene-based materials [57] or to evaluate the impact of nanomaterials on different DNA repair pathways [141].…”