No cytotoxicity or genotoxicity of graphene and graphene oxide in murine lung epithelial FE1 cells in vitro

Abstract

Graphene and graphene oxide receive much attention these years, because they add attractive properties to a wide range of applications and products. Several studies have shown toxicological effects of other carbon‐based nanomaterials such as carbon black nanoparticles and carbon nanotubes in vitro and in vivo. Here, we report in‐depth physicochemical characterization of three commercial graphene materials, one graphene oxide (GO) and two reduced graphene oxides (rGO) and assess cytotoxicity and genotoxicity in the murine lung epithelial cell line FE1. The studied GO and rGO mainly consisted of 2–3 graphene layers with lateral sizes of 1–2 µm. GO had almost equimolar content of C, O, and H while the two rGO materials had lower contents of oxygen with C/O and C/H ratios of 8 and 12.8, respectively. All materials had low levels of endotoxin and low levels of inorganic impurities, which were mainly sulphur, manganese, and silicon. GO generated more ROS than the two rGO materials, but none of the graphene materials influenced cytotoxicity in terms of cell viability and cell proliferation after 24 hr. Furthermore, no genotoxicity was observed using the alkaline comet assay following 3 or 24 hr of exposure. We demonstrate that chemically pure, few‐layered GO and rGO with comparable lateral size (> 1 µm) do not induce significant cytotoxicity or genotoxicity in FE1 cells at relatively high doses (5–200 µg/ml). Environ. Mol. Mutagen. 57:469–482, 2016. © 2016 The Authors. Environmental and Molecular Mutagenesis Published by Wiley Periodicals, Inc.

Differences in inflammation and acute phase response but similar genotoxicity in mice following pulmonary exposure to graphene oxide and reduced graphene oxide

“…Lateral size, specific surface area, C/O and C/H ratios were determined using transmission electron microscopy (TEM), Brunauer–Emmet–Teller (BET) and combustion elemental analysis, respectively. a Adapted from Bengtson et al [26]. …”

In vivo toxicological evaluation of graphene oxide nanoplatelets for clinical application

“…15,16 The safety and biocompatibility of GO has been a subject of intense research in the scientific community. The reports have been controversial, some reported that GO is nontoxic, even in a high dose of 200 µg/mL after 24 hours of exposure to cells lines, 17,18 while others reported that GO interacted with DNA and induced mutagenesis in the MDA-MB-231 human breast cancer cells. 19 In fact, GO, even at the low dose of 10 µg/mL, altered gene expression patterns and caused cell apoptosis.…”

A closer look at the genotoxicity of graphene based materials

“…However, it was observed that the cells exposed to graphene materials for 24 h did not affect cytotoxicity in terms of cell viability and cell proliferation. In addition, no genotoxicity was observed by Comet assay analysis in cells exposed to graphene for 3 and 24 h [38].…”

“…In vitro genotoxicity studies involving healthy primary cells or cell lines. Comet assay, qRT-PCR, DNA methylation assay [35] GQDs (lateral size of 40 nm, thickness of 2 nm) NIH-3T3 3 and 24 h 5, 50 μg ml −1 IF for XRCC4 and OGG1 expression, flurimetric DCFH-DA assay [36] GO-S (100 nm), GO-L (10 μm) BEAS-2B 0-12 h 12.5, 25, 50 μg ml −1 Alkaline Comet assay [37] LA-PEG-GO (100-200 nm), PEG-GO (50-150 nm) and PEI-GO (200-500 nm) HLF 2, 4, 12, 24 h 1, 10, 50, 100 μg ml −1Comet assay, SOD measurement, flurimetric DCFHmg ml −1 Flurimetric DCFH-DA, Comet assay[38] …”