Graphene Oxide: Purified Graphene Oxide Dispersions Lack In Vitro Cytotoxicity and In Vivo Pathogenicity (Adv. Healthcare Mater. 3/2013)

Abstract

Preparation of a high dispersibility graphene oxide (GO) that can be reliably used in biological investigations is reported by Kostas Kostarelos and co‐workers . Exposure of cells and tissue to the graphene oxide indicated a lack of cytotoxic responses in human cell cultures (in vitro) and after injection to living animals (in vivo).

Graphene: Safe or Toxic? The Two Faces of the Medal

“…40 Dose‐dependent toxicity on cells was observed (i.e., 3–100 μg mL −1 concentration). An opposite result was reported in two independent studies showing that GO induced only a slight decrease on proliferation of the A549 cell line without signs of apoptosis or cell death in a range of concentrations between 7.8 and 200 μg mL −1 41–43. The same material, treated with hydrazine to generate rGO, resulted instead in high cytotoxicity, thus significantly lowering the viability of the same type of cells 41…”

“…49 In contrast, the presence of contaminants as unreacted graphite oxide or graphitic fractions might be also responsible for inflammation. Indeed, when GO is extensively purified using several washings and centrifugation steps it did not show an increase in the level of proteins and polymorphonuclear leukocytes on days 1 and 7 after peritoneal administration (injected dose of 50 μg per animal) 43. No collection of giant cells, inflammatory response, and formation of granuloma were evidenced in comparison to long pristine multiwalled carbon nanotubes (Figure 5).…”

“…Low and high magnifications of the SEM images are shown. Reproduced with permission 43. Copyright 2012, Wiley‐VCH Verlag GmbH & Co.…”

Graphene and Graphene‐Based Materials in Biomedical Science

“…[343] Also few researchers have recently found that pure and highly dispersable GO with 1-2 nm in thickness did not show any inflammatory response or granuloma formation at the mesothelial membrane after intraperitoneal injections. [344] Though there are no sufficient number of works available regarding the cytoxicity of graphene and braphene-based materials, [345] it is evident that different graphene and graphenebased materials will have a varying toxicological profile. There will be different conditions and effects when once exposed and also various factors are to be addressed and carefully noted before deriving to a valid conclusion.…”

Prospects and Challenges of Graphene in Biomedical Applications

“…It should be noted that the commercially available graphene ‘ nanoplatelet’ materials were not chemically or surface modified, therefore presumably hydrophobic and not very well dispersed. Some of us have recently reported that pure and highly dispersable GO with 1–2 nm in thickness and below 500 nm in lateral dimensions show no inflammation or granuloma formation at the mesothelial membrane after intraperitoneal injections 87. The most important in vivo studies investigating the toxicological side effects of graphene using in vivo models are shown in Table 4 .…”