Papers by Author: Motohiro Uo

Abstract: In this study, we succeeded in preparation and characterization of two types of biocompatible polymer-coated inorganic nanoparticles (cupper and silicone oxide). As a biocompatible polymer, gelatin and poly(lactic acid) were used. For determination of their biodistribution, the obtained particles were administered to mice through the tail vein. After administration, the particles in some organs were determined with energy-dispersed X-ray spectrometer. The cupper nanoparticles were observed in the lung and kidney, while the silica particles were in the lung, liver and spleen. The distribution behaviors were quite different from non-polymer coated nanoparticles

Abstract: Carbon nanotubes (CNT) and their derivatives with different structure and compositions have unique features. In the present study, cell proliferation was performed on various nanotubes such as single walled CNTs, multiwalled CNTs and imogolite which is nanotubes of aluminosilicate. SEM observation of the growth of osteoblast-like cells cultured on CNTs showed the morphology fully developed for the whole direction, which was different from that extended to the one direction on the usual scaffold. Numerous filopodia were grown from cell edge, extended far long and combined with CNT meshwork. Apatite precipitation in simulated body fluid, affinity for proteins and saccharides, and nanosize meshwork structure with large porosity would be the properties responsible for these cell adhesion and growth. Imogolite showed the similar properties to CNTs. Nanotubes could be the favorable materials for biomedical applications.

Abstract: Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.

Abstract: Internal distributions of several inorganic microparticles administered into the tail vein of mice were determined using a Scanning X-ray analytical microscopy and energy-dispersed X-ray spectroscopy. After administration through the tail vein of mice, the particles circulated by blood flow then reach some organs and temporally remained. In this study, we determined that the distribution behaviors in body depend upon the chemical species and the size.

Abstract: Both biochemical cell functional test and animal implantation test were done to investigate the reaction to fine particles. Particles cause nonspecifically phagocytosis to cells and inflammation to tissue for the size below 10m. With the size below 50nm particles may invade into the internal body through the respiratory or digestive system and diffuse inside body. Ti mapping by XSAM after the compulsory exposure test to the respiratory system showed the internal diffusion of 30nm TiO2 particles. They diffused with time course to lung, liver and spleen after injection from caudal vein. Nanoparticles might be the objects whose existence has not been assumed by the biophylactic system.