In vivo internal diffusion of several inorganic microparticles through oral administration

Issue title: Selected papers presented at the International Symposium on Nanotoxicity Assessment and Biomedical Environmental Application of Fine Particles and Nanotubes, Hokkaido, Japan, 16–17 June 2008, Part 2

Article type: Research Article

Authors: Abe, Shigeaki^; | Koyama, Chila | Esaki, Mitsue^; | Akasaka, Tsukasa | Uo, Motohiro | Kuboki, Yoshinori^; | Morita, Manabu | Watari, Fumio

Affiliations: Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan | School of Dental Medicine, Hokkaido University, Sapporo, Japan | Department of Preventive Dentistry, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan | Department of Oral Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan | Koken Bioscience Institute, Tokyo, Japan

Note: [] Address for correspondence: Shigeaki Abe, Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586, Japan. E-mail: sabe@den.hokudai.ac.jp.

Abstract: We observed the internal diffusion behavior of inorganic micro/nano particles through oral administration. By oral exposure, the fed particles were absorbed through the digestive system then reached some organs after internal diffusion in the body. For example, TiO2 particles fed to mice were detected in the lung, liver, and spleen after 10 days of feeding. Whereas, the absorption efficiency was extremely low compared with intravenous injection. In a comparison of the simple amount of administration, oral exposure required 102 times or more amount by intravenous injection for detection by an X-ray scanning analytical microscope. During dental treatment, micro/nano particles from tooth or dental materials would generate in the oral cavity, and some of the particles had a possibility to be swallowed, absorbed through the digestive system, and then diffuse into the body. However, our results suggest that biocompatible microparticles that are naturally taken orally affect animals only rarely because of the low absorption efficiency.

Keywords: Biodistribution, micro-sized particles, nano-sized particles, oral administration

DOI: 10.3233/BME-2009-0584

Journal: Bio-Medical Materials and Engineering, vol. 19, no. 2-3, pp. 221-229, 2009