| Project/Area Number |
17310064
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nanomaterials/Nanobioscience
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| Research Institution | Ibaraki University (2006-2007)
Tohoku University (2005) |
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Principal Investigator |
KOBAYASHI Yoshio Ibaraki University, College of Engineering, Professor (40250849)
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| Co-Investigator(Kenkyū-buntansha) |
TAKEDA Motohiro Tohoku University, Graduate School of Engineering, Associate Professor (10333808)
OHUCHI Noriaki Tohoku University, Graduate School of Medicine, Professor (90203710)
KASUYA Atsuo Tohoku University, Center for Interdisciplinary Research, Professor (10005986)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥15,490,000 (Direct Cost: ¥14,500,000、Indirect Cost: ¥990,000)
Fiscal Year 2007: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2006: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2005: ¥8,200,000 (Direct Cost: ¥8,200,000)
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| Keywords | X-ray contrast agent / MRI / nanoparticle / encapsulation / Agl / Gd / silica / sol-gel method / 追添加 / MRI造影剤 / 粒子 / 蛍光ビーズ / コア-シェル型 / ゾル-ゲル法 |
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| Research Abstract |
Iodine compounds and gadolinium compounds have been used as contrast agents for X-ray CT and magnetic resonance imaging, respectively. These existing compounds may provoke adverse events as allergic reactions in patients, so that they can not be administered to such people. Core-shell nanoparticles are good candidates for prevention of allergic reactions because the shell materials can keep the contrast agents from living systems. In present works, several methods for silica-coating of contrast agent nanoparticles are proposed.
Silica-coating of AgI nanoparticles with a Stober method was carried out to find out reaction conditions for control of the shell thickness. The AgI nanoparticles were prepared from AgCIO_4 and KI with the use of 3-mercaptopropyltrimethoxysilane (MPS) as a silane coupling agent and dimethylamine (DMA) catalyst for alkoxide hydrolysis. AgI-silica core-shell particles could be prepared with the use of 4.5×10^<-5> MMPS, 20M water, 0.01 MDMA and 1 mM AgI. Silica shell thickness could be varied from 15 to 28 nm with an increase in the TEOS concentration from 0.005 to 0.04M.
A preparation method for multilayered silica-Gd-silica core-shell particles is proposes. Silica particles with an average size of 30.9 nm were prepared by the Stober method. Silica-Gd core-shell particles with a size of 57.4 nm were synthesized by a homogeneous precipitation method at 80℃ in water/propanol solution with 27.7 M H_2O, 0.001 M Gd (NO_3)_3, 0.5 M urea and 1 g/l polyvinylpyrrolidone in the presence of 0.001 vol% suspension of the silica particles. Succeeding silica-coating of the silica-Gd core-shell particles was performed with 0.0133 MTEOS and 0.002 M NaOH in the presence of a suspension of silica-Gd core-shell particles. Consequently, multilayered silica-Gd-silica core-shell particles with an average size of 71.2 nm could be obtained. These particles exhibited clear enhancement in magnetic resonance images.
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