S9-5※ Development and evaluation of single particle ICP-MS analysis to reveal the distribution of nanoparticles in the body

Nanoparticles (NPs) that are smaller than 100 nm are widely used in various products including cosmetics, foods, and medicines, Because of their beneficial properties such as enhanced tissue permeability and surface reaction compared to other micro or larger sized materials. In contrast, the risk analysis of NPs is needed, since NPs exhibit different pharmacokinetics from other micro or larger sized materials and may induce unknown biological responses. From this respect, hazard identification of NP has been analyzed worldwide. On the other hand, few studies have examined the exposure situations and kinetics for NPs. Especially, it was recently reported that particles were re-formed from metal ions as well as that metal NPs ionized. Furthermore, we reported that the difference of their physical properties, such as particles size or distinguish between particles and ions, affected biological responses. Therefore, it is necessary to evaluate their physical properties in the body, in order to understand the safety of NPs. However, it is difficult to quantitatively analyze their physical properties in the body in the conventional methods, so that the development of a new technology which establish them, has been required. In this regard, we have developed the technology that can quantitatively analyze their physical properties in the body by optimizing the pretreatment method for biological samples. In this symposium, I would like to introduce an overview of the technology and discuss how to ensure the safety of pharmaceuticals, foods, and cosmetics in humans. S9-4 動物実験に依存しない化粧品の安全性評価に関する取り組み