**1. Introduction**

Organ and tissue transplantation has limitations like immune reactions and donor limited availability, leading to the necessity for bioactive tissue engineering biomaterials, which is a rapidly developing multidisciplinary field. Nanoparticles (NP) based biomaterials offer better control over their desirable properties, such as the controlled release of biological molecules at surgical sites and optimization of mechanical properties matching recipient sites [1, 2]. Nanotechnology includes the development of NP and their applications in wide areas of interest. The size of NP will be within the range of ∼10–1000 nm which can be synthesized in colloid and solid states [3]. Due to the increased production and use of nanoparticles in various fields, the unintended toxicity of nano biomaterials is a growing concern in tissue engineering and regenerative medicine. Minimal data are available regarding their toxicity and end products in the

human physiologic system. Exposure pathways for NP include dermal penetration, ingestion, and inhalation. Physical properties of NP that influence toxicity include surface chemistry, particle shape, and size [4].

This chapter presents toxicological profiles of NP used as biomaterials highlighting in vitro and in vivo analysis techniques. This will give an insight into overall patterns and further requirements for assessing the toxicity of these biomaterials.
