Low-voltage and high-voltage TEM observations on MWCNTs of rat in vivo
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
Affiliations: Center for Advanced Research of Energy Conversion Materials, Hokkaido University, Sapporo, Japan | Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan | Frontier Research System, Riken, Saitama, Japan
Note: [] Address for correspondence: Norihito Sakaguchi, Center for Advanced Research of Energy Conversion Materials, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo 060-8628, Japan. Tel.: +81 11 706 6768; Fax: +81 11 706 6768; E-mail: sakagu@ufml.caret.hokudai.ac.jp.
Abstract: In the present study, we focused on the optimal conditions for observation of morphology and atomic structure of carbon nanotube (CNT) in vivo by transmission electron microscopy (TEM). Either low-voltage or high-voltage TEMs was chosen for the high-contrast or high-resolution imaging of subcutaneous tissue and the multi-wall CNT (MWCNT). The morphology and structure of each cell organelle were well recognized using the low-voltage TEM at 75 kV. Individual MWCNTs forming the cluster were also visible by the low-voltage TEM. On the contrary, the high-voltage TEM image at 1250 kV shows poor contrast on both the cell organelles and MWCNTs. However, graphene layers of MWCNT were clearly visible in the HRTEM image using the high-voltage TEM. The influence of the surrounding biological tissue can be disregarded by the high-energy electrons due to their weak scattering/absorption effect in the tissue. It was indicated that the usage of the high-voltage TEM is quite effective to the atomic structure analysis of nano-crystalline materials in vivo.
Keywords: Low-voltage and high-voltage transmission electron microscopy, high-resolution electron microscopy, multi-wall carbon nanotube, in vivo
