Current Updates On the In vivo Assessment of Zinc Oxide Nanoparticles Toxicity Using Animal Models

Zinc oxide nanoparticles (ZnO NPs) is one of the most exploited nanoparticles in the biomedical field due to its enormous potential in disease diagnostics and monitoring. The upsurge in demand for ZnO NPs due to its peculiar properties and vast applications has led to an increase of inadvertent exposure of ZnO NPs to humans, resulting in higher risk for nanotoxicity. Previous literature is strongly suggestive of the notion that ZnO NPs may induce adverse health effects in humans and organisms in the environment. Hence, knowledge of the physiological interactions of ZnO NPs with the biological system as well as understanding the interplay between the physicochemical properties of ZnO NPs and its toxic effects are key factors in developing ZnO NPs that can be safely applied in the biomedical field. At present, many experiment models have been employed to unveil the possible unforeseen effect of ZnO NPs on the human, animals, and environment. Among these experiment models, animal models are of paramount importance as it allows the prediction of the possible toxic effects of ZnO NPs in individual organs or the body as a whole. The current review systemizes and summarizes the in vivo assessments of organ-specific nanotoxicity of ZnO NPs using animal models published between 2015 and 2020. Besides, this review attempts to outline the possible mechanisms of ZnO NPs–induced toxicity and factors influencing these toxic effects of ZnO NPs.