Accumulation and toxicity of intravenously-injected functionalized graphene oxide in mice.

Graphene and its functionalized derivatives have recently emerged as interesting nanomaterials with promising applications in biomedicine. In this study, the long-term in vivo biodistribution of intravenously injected nanographene oxide (NGO) functionalized with poly sodium 4-styrenesulfonate (PSS) was systematically examined and the potential toxicity over 6 months of NGO-PSS nanoparticles was investigated. Our results showed that the nanoparticles mainly accumulate in the lung, liver and spleen, where they persist for at least 6 months. These nanoparticles result in acute liver injury and chronic inflammation of the lung, liver and spleen, as evidenced by blood biochemistry results and histological examinations.