Assessment of the lung toxicity of copper oxide nanoparticles: current status

Copper oxide nanoparticles (CuO NPs) are being used in several industrial and commercial products. Inhalation is one of the most significant routes of metal oxide NP exposure. Hence, the toxicity of CuO NPs in lung tissues is of great concern. In vitro studies have indicated that CuO NPs induce cytotoxicity, oxidative stress and genetic toxicity in cultivated human lung cells. Leaching of Cu ions, reactive oxygen species generation and autophagy appear to be the underlying mechanisms of Cu NP toxicity in lung cells. In vivo studies on the lung toxicity of CuO NPs are largely lacking. Some studies have shown that intratracheal instillation of CuO NPs induced oxidative stress, inflammation and neoplastic lesions in rats. This review critically assessed the current findings of the toxicity of CuO NPs in the lung.