The concern regarding the safety of nanomaterials for the human body is constantly raising. On one hand, there is an increase in the production of nanomaterials for technological applications, which raises the risk of accidental exposure of the workers during the technological manipulation. On the other hand, nanomaterials can be designed for medical applications and their faith in the human body, along with their interactions with different tissues, becomes of vital importance.The mechanisms involved in nanomaterials toxicity are discussed, including oxidative stress and inflammation. In vivo toxicity evaluation includes different routes of administration or interaction between the nanomaterial and the organism, as well as a short-term or a long-term exposure or evaluation. "lso, the characteristics of nanomaterials, including size, shape, impurities, function, surface coating in relation to their toxicity, were discussed. " particular attention has been given to the evaluation of the toxicity of dendrimers, silver nanoparticles, gold nanoparticles and carbon nanotubes.Keywords: toxicity, oxidative stress, nanoparticles, carbon nanotubes
. IntroductionResearch in the field of nanomaterials and nanotechnology has seen exponential growth in recent years due to multiple applications in different areas such as molecular imaging, drug delivery, engineering technology, and development of materials and medical devices for diagnosis and treatment. Generally, the biological effects of nanomaterials depend on their © 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. electronic, magnetic, optical, and mechanical properties and also on their size, composition, and shape.However, the impact of these nanomaterials on human and environmental health is still limited. Most studies have investigated only the effects of unintended exposure inhalation, medical procedures or accidental ingestion and evaluated especially local effects, at the access site [ , ]. Nevertheless, due to the development of various biomedical procedures using nanomaterials it is necessary to understand their potential toxic effects at systemic level."n increasing number of studies published in the last decade have tried to decipher the complexity of interactions between different types of nanomaterials and cells. Nanomaterials usually get into the body either by inhalation and ingestion or transcutaneous [ , ], most often accidentally in the process of synthesis, through their usage, after wearing gold and silver jewelry or by eating food containing gold. Nevertheless, the behavior of nanoparticles inside the cells is still an enigma, and not all the metabolic and immunological responses induced by these particles are completely understood. In addition, the conclusions obtained have been variable and contrad...