Thermal Reduction of Graphene Oxide Mitigates Its In Vivo Genotoxicity Toward Xenopus laevis Tadpoles

Abstract

The worldwide increase of graphene family materials raises the question of the potential consequences resulting from their release in the environment and future consequences on ecosystem health, especially in the aquatic environment in which they are likely to accumulate. Thus, there is a need to evaluate the biological and ecological risk but also to find innovative solutions leading to the production of safer materials. This work focuses on the evaluation of functional group-safety relationships regarding to graphene oxide (GO) in vivo genotoxic potential toward X. laevis tadpoles. For this purpose, thermal treatments in H2 atmosphere were applied to produce reduced graphene oxide (rGOs) with different surface group compositions. Analysis performed indicated that GO induced disturbances in erythrocyte cell cycle leading to accumulation of cells in G0/G1 phase. Significant genotoxicity due to oxidative stress was observed in larvae exposed to low GO concentration (0.1 mg.L−1). Reduction of GO at 200 °C and 1000 °C produced a material that was no longer genotoxic at low concentrations. X-ray photoelectron spectroscopy (XPS) analysis indicated that epoxide groups may constitute a good candidate to explain the genotoxic potential of the most oxidized form of the material. Thermal reduction of GO may constitute an appropriate “safer-by-design” strategy for the development of a safer material for environment.

Electroresponsive Silk-Based Biohybrid Composites for Electrochemically Controlled Growth Factor Delivery

“…Moreover, hydroxynaphthalene derivatives such as rGO were demonstrated as estrogen receptor modulators [59]. Our in silico mutagenicity screening studies of these nanomaterials (Table S2) using Sarah Nexus (Sarah Nexus: 3.0.0, Sarah Model: 2.0) also suggested that graphene, GO and rGO may be mutagenic, supported by in vitro and in vivo studies using graphene quantum dots [60], GO [61] and rGO [62]. Therefore, the specific method to use drug delivery devices based on these composites needs to be considered.…”

From Basic Research to New Tools and Challenges for the Genotoxicity Testing of Nanomaterials

“…As already reported in the literature, oxidative stress was suggested as one mechanism involved in the genotoxic responses observed [ 2 , 3 , 4 , 9 ]. Co-exposure to nanomaterials and other compounds can affect the genotoxicity [ 2 , 6 ].…”

“…In addition to classical cell lines such as hamster and human fibroblasts [ 1 , 2 ] or human lung cells [ 3 , 4 ], new models have been also used for investigating nanomaterials genotoxicity: ToxTracker reporter cell lines [ 5 ], human amniotic cells [ 6 ] and 3D HepG2 spheroids [ 7 ]. In this issue, three papers also deal with in vivo studies: on the plant Allium cepa [ 8 ], on the tadpoles of Xenopus laevis [ 9 ] and on rats [ 10 ]. Moreover, a broad range of nanomaterials have been tested, including plastic particles [ 2 ] that recently became of increasing concern for environmental and public health.…”

“…Among the various assays available for investigating genotoxicity and mutagenicity, most of the papers used the comet assay to visualize the DNA fragmentation both in in vitro [ 3 , 4 , 6 , 7 ] and in vivo [ 10 ] studies. The micronucleus assay to detect chromosome and genome mutations was also largely performed in cell lines [ 2 , 4 ] as well as in whole organisms [ 8 , 9 , 10 ]. In contrast, only one article deals with the gene mutation Hprt assay [ 1 ].…”

“…Concerning the role of the physico-chemical characteristics, it was reported that the surface area is one of the dose metrics showing a better correlation with the genotoxicity of quantum dots [ 5 ], while the metal/coating agent ratio is a key parameter for the toxicity observed with the commercially available AgNPs formulation Argovit™ [ 8 ]. Similarly, the thermal reduction of graphene oxides generates a material that was no longer genotoxic at low concentrations [ 9 ]. In contrast, the type of synthesis used for producing tungstene particles did not significantly affect the toxicity [ 4 ].…”