Nanotoxicology of common metal oxide based nanomaterials: Their ROS-y and non-ROS-y consequences

Abstract

Inorganic nanomaterials form the bulk of the nanomaterials (NMs) found in consumer products that can easily enter into the food chain, biosystems and environment. Because of their sizes and associated material characteristics, many studies have shown a fair degree of toxicity associated with these NMs. This review consolidates and discusses the nanotoxicity of three commonly found inorganic oxide NMs, namely titanium dioxide, zinc oxide and silicon dioxide. Because oxidative stress in the form of reactive oxygen species (ROS) is a major mediator of nanotoxicity, we have centered much of our discussion on mechanisms before and after ROS production due to these common NMs. These NMs do exhibit non-ROS effects, not as well characterized but still biologically important. The physiological transport of NMs and how they intersect with biological mechanisms that finally brought about cell death gave some insights of how these NMs might behave in biological systems and thus illustrate the impact of this new class of materials on human health. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.