In the last decades, nanoscience had a spectacular evolution providing new, versatile engineered nanomaterials and nanotools with a plethora of applications in very diverse fields ranging from energy storage to medicine. Among the palette of nanomaterials, magnetic nanoparticles (in particular iron oxide-based) present unique physicochemical properties that are actively being exploited in the biomedical field. Currently, they are used for induced magnetic hyperthermia cancer treatments, as contrast agents for magnetic resonance imaging, as cell tracking elements, and for drug delivery modalities. In parallel to the growth of nanoscience and the ever-increasing applications of nanomaterials, concerns regarding the safety and toxicity of nanoparticles have arisen, both during and post-administration. In this chapter, we review key concepts related to nanotoxicology and to the fate of nanomaterials in the human body. A detailed description about the most accepted and practiced in vitro and in vivo methods used to evaluate the toxicity of nanomaterials is provided, with emphasis in magnetic nanomaterials for nanomedicine applications.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada
