| Project/Area Number |
07680938
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
HANAICHI Takamasa Nagoya Institute of Technology, Faculty of Engineering, Assist, Prof., 工学部, 助手 (90252311)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAGUTI Takeshi Nagoya Institute of Technology, Faculty of Engineering, Assoc.Prof., 工学部, 助教授 (80144195)
MARUNO Shigeo Nagoya Institute of Technology, Faculty of Engineering, Prof., 工学部, 教授 (60024204)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1996: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1995: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | dextran derivatives / magnetic fluid / ultra-fine magnetite (Fe_3O_4) / TEM / spleen / electron diffraction / pulse NMR / Berlin blue iron reaction / 生体適合性磁性流体 / 磁性酸化鉄超粒子 / デキストラン / 核磁気共鳴 / MRI造影剤 / 電子線回折法 / 大食細胞 |
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| Research Abstract |
Dextran-iron oxide magnetic fluid (DM) has been developed as a new type of contrast agent designed for magnetic resonance imaging (MRI). the DM is also attracted much attention as an auxiliary agent in hyperthemia. We have prepared three kinds of DM complex consisting of the different dextran derivatives and a ultra-fine magnetite (Fe_3O_4) core : i.e., alkali-treated-dextran -magnetite (ATDM), carboxy-methyl-dextran-magnetite (CMDM), and carboxymethyl-diethylamino-dextran-magnetite (CMEADM). The knowledge about behavior of these DM particles injected into living body is important for medical use in MRI and hyperthemia. Thus, metabolism and taking-up of the DM in rat organs is investigated by the optical microscope (OM) and transmission electron microscope (TEM), as well as pulse NMR method. In this study, we report mainly the results of CMEADM,in comparison with those of ATDM and CMDM.
The results of NMR measurements of DM after iv-injection show that the half time of blood clearance l
… More
argely depends on the microstructure of the DM and the values are 1.5,2.8 and 9.2 hours for ATDM,CMDM and CMEADM,respectively. It has been found from OM observation and pulse NMR measurments that these DM are mostly accumlated in the liver and spleen through the metabolism. After 1 week from injection, the CMEADM could not be detected in the liver by the Berlin blue iron reaction, suggesting that they was removed from the liver within three-four days. While in spleen, the CMEADM taken-up in the macrophage is observed at the marginal zone of red pulp and moves to the outer-part of the marginalzone with increase in time elapsing, and after an elapse of 12 weeks the CMEADM does not exist in the marginal zone and locates in the red pulp. The TEM observation revealed that the CMEADM particles are taken-up in the lysosoms of macrophage at the marginal zone for the samples after 6 weeks. The electron diffraction patterns from the CMEADM which exists in the lysosomes of macrophage was attributable to magnetite. However, for the samples after 12 weeks, the amolphous pattern were observed. The similar metabolic process has been also recognized for liver tissue within a relatively short period of time after injection. One might conclude that the DM has the biocompatible character and is assimilated in the red pulp in compliance with the conventional iron metabolism. Less
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