Testing Nanotoxicity: An Update of New and Traditional Methods

The toxicity of engineered nanomaterials (NMs) represents a matter of concern for the regulatory agencies. Although rarely reported as an accidental event in humans, the exposure to airborne nanoparticles (NPs) in polluted environments, urban or professional, can trigger inflammatory or allergic reactions in airways or skin with different degrees of severity. A new science, nanotoxicology, evolved in the last decade, imposing the development of suitable methods and standard materials, now available through the international agencies. In recent years, the study of the behavior of this set of NMs in culture media and biological fluids added important knowledge to their toxicity. Among others, we recall here the interactions of NMs, dispersed in blood or other complex fluids, with proteins, circulating cells, and macrophages. These mechanisms are of primary importance for the control of biodistribution, clearance, and toxicity of NMs, as is the route of entering an organism. The coincidental development of computational models to describe and predict this complex behavior represents an emerging field of study, which requires innovative methods, such as quantum chemistry and integrative parameters.