Several types of nanoparticles are being evaluated for therapeutic and diagnostic applications. Although the biocompatibility of these nanoformulations has been evaluated in different models, it is of utmost importance to standardize the tests in order to advance our knowledge in this area. This book chapter summarizes experimental results related to the in vitro and in vivo toxicity of three types of nanoparticles: gold, silica and poly(lactic-co-glycolic acid). The chapter gives an overview about the methodologies that can be used to evaluate the toxicity of the nanoparticles. Whenever possible, a correlation between NP size, chemical composition, charge and concentration with toxicity is given. We further discuss the main mechanisms of nanomaterials toxicity including cell membrane perturbation, oxidation stress, and inflammatory response.
Keywords: Gold nanoparticles, in vitro cytotoxicity, in vivo cytotoxicity, inflammatory response, mechanism of cytotoxicity, membrane perturbation, oxidative stress, PLGA nanoparticles, silica nanoparticles, size/shape induced cytotoxicity.