Experimental Models in Nanotoxicology

Abstract

The aim of toxicology is to characterise the potentially harmful effects of solid, liquid, or gaseous substances for humans. Having evaluated the hazards, and given the level of exposure to the substance, we can then assess the risks. The term ‘nanotoxicology’ was first used in the editorial of a scientific review in 2004 [1]. The authors explicitly recommended the creation of a new branch of toxicology called nanotoxicology, which would focus on the specific problems that might be raised by nanoparticles. Even then, it was expected that the particular physicochemical properties of nanomaterials might lead to novel toxic effects requiring special investigative methods. In experimental toxicology, the underlying principle is always the same. Individuals, tissues, or cells are exposed to the substance under investigation, and the resulting response is compared with a control group treated under the same conditions, but without the exposure to the substance. As far as this approach is concerned, nanoparticles are no different from other more conventional substances like chemical products. In some cases, humans are deliberately exposed. We then speak of con- trolled exposure. But for obvious ethical reasons, such experimentation is limited, and restricted to parameters accessible by non-invasive techniques. The vast majority of toxicological studies appeal to animal models (in vivo toxicology) or cell models (in vitro toxicology).When extrapolating results to humans, these models clearly require some reflection. At this point, mathe- matical modelling (in silico toxicology) can sometimes be of use.