ABSTRACT
The field of nanotechnology has seen exponential growth due to its multiple applications in different areas of modern life. This leads to greater chances of direct and indirect exposure. This is the rationale behind different government agencies and research organizations efforts to standardize methodologies for in vivo studies to determine the safety of these materials. Human exposure to nanoparticles occurs through the respiratory tract, skin contact, gastrointestinal tract, and parenteral administration. In vivo studies enable the establishment of the role of pharmacokinetics in toxicity. There are various animal models for the evaluation of toxicity; aquatic models represented by Daphnia magna and zebrafish Danio rerio, and mammal models represented by murine, are three of these. It is important to point out that in order to demonstrate the inocuity of a nanoparticle, the researcher has to carry out tests at least in two forms, acute and subchronic, since the study must mimic what occurs in human beings who may be exposed in those two forms. There are different physicochemical properties to be considered when dealing with nanoparticle toxicity. These variables impact the effects of drugs inside the body. Nanoparticle toxicity is related to its deposition grade and the toxicity mechanisms involved, which include oxidative stress, genotoxicity, DNA damage, inflammations, and fibrosis. The effect of the different routes of administration must be evaluated when dealing with nanoparticle toxicity, keeping in mind special tests where the effects on fertility and the carcinogenic and teratogenic potentials are assayed. In this chapter, some of the methods that have been used by a many experimental studies on nanoparticle toxicity, which have been successful in describing toxicity targets and the mechanisms involved, are outlined. Research in this field is, therefore, a critical aspect in current times that shall determine the risk/benefit ratio of the use of nanoparticles, and consequently their future that seems to be potentially promising.
