Single-layer GO sheets were internalized

in cytoplasmic, membrane-bound vacuoles by human lung epithelial cells or fibroblasts and induced toxicity at doses above 20 μg/mL after 24 h [65]. Recently, Singh and coworkers investigated amine-modified Caspase Inhibitor VI clinical trial graphene on human platelets, and they found that neither had no stimulatory effect on human platelets nor did it induce pulmonary thromboembolism in mice and suggested that G-NH2 is the safest graphene derivative with potential for biomedical applications due to its lack of thrombotic and hemolytic activities. Biocompatibility of graphene films was compared with carbon nanotubes using a mouse fibroblast cell line (L-929) to assess the cytotoxicity; the results suggested that the cells adhered and proliferated on graphene film well than carbon nanotubes,

which indicated that the material is biocompatible Go6983 molecular weight [67, 68]. Akhavan et al. [69] demonstrated that size and concentration are dependent on the cytotoxicity and genotoxicity of graphene oxide sheets and nanoplatelets in the hMSCs and found that the reduced graphene oxide nanoplatelets with average lateral dimensions of 11 nm exhibited a strong potential in the destruction of the cells. The destruction of cells is due to contact PF-6463922 interaction of the extremely sharp edges of graphene with the cells, and the possible mechanisms could be oxidative stress which eventually leads to DNA fragmentations and chromosomal aberrations. Furthermore, Akhavan et al. [70] reported that the single-layer reduced graphene oxide nanoribbons could penetrate into the cells and cause DNA fragmentations as well as chromosomal aberrations, even at a low concentration

of 1.0 μg/mL after a short exposure time of 1 h in hMSCs. Figure 8 Effect of GO and S-rGO on cell viability of PMEF cells. Cell viability of PMEF cells was determined using WST-8 assay after a 24-h exposure to different concentrations of GO or S-rGO. The results represent the means of three separate experiments, and error bars represent the standard error of the mean. GO-treated groups showed statistically significant differences from the control group by Student’s t test (p < 0.05). Impact of GO and S-rGO on membrane integrity The reactive PAK5 oxygen species (ROS) generated in a concentration-dependent graphene is known as one of the important mechanisms describing the cytotoxicity of graphene [64]. Therefore, because we are interested to evaluate the biocompatibility of GO and S-rGO on cell membrane damage, LDH release (cell membrane damage marker) was measured. As shown in Figure 9, a significant LDH release was observed in the cells treated with GO compared to the control group, and no obvious differences were observed even at higher concentrations of S-rGO treated against the control group.