Biomedical Applications of Nanodiamonds and Nanotoxicity Problems

Nanodiamonds (NDs) attract much attention due to their unique chemical and physical properties, and numerous applications in medicine and biology. Nevertheless the problem of their invasion and accumulation in the cells, and mechanisms of their extraction from the organisms are not clear. In this paper a detailed review of literature on biotoxicity of NDs and their influence on cells and tissues is presented. It is shown, the effects are dose- and size-dependent, and depend on the administration type (puerperal, intratracheal, etc.). Besides, the opposite effects (both cytotoxic and non-toxic) have been observed on the same animals by different authors. Radio protective ability and cytotoxicity of the NDs with sizes 210 nm have been studied on rats with different type of administration with food of aqueous suspensions of NDs homogenized by ultrasound treatment followed by X-ray exposition (5.8g, 5 min). It was shown, administration of NDs produce no cytotoxic influence. Radioprotective influence of NDs have also been confirmed.