Enhancing Transversal Relaxation for Magnetite Nanoparticles in MR Imaging Using Gd3+-Chelated Mesoporous Silica Shells

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• 作者：Chih-Chia Huang ; Chiau-Yuang Tsai ; Hwo-Shuenn Sheu ; Kuei-Yi Chuang ; Chiu-Hun Su ; U-Ser Jeng ; Fong-Yu Cheng ; Chia-Hao Su ; Huan-Yao Lei ; Chen-Sheng Yeh
• 刊名：ACS Nano
• 出版年：2011
• 出版时间：May 24, 2011
• 年：2011
• 卷：5
• 期：5
• 页码：3905-3916
• 全文大小：1285K
• 年卷期：0
• ISSN：1936-086X

文摘

A new magnetic nanoparticle was synthesized in the form of Gd³⁺-chelated Fe₃O₄@SiO₂. The Fe₃O₄ nanoparticle was octahedron-structured, was highly magnetic (∼94 emu/g), and was the core of an encapsulating mesoporous silica shell. DOTA-NHS molecules were anchored to the interior channels of the porous silica to chelate Gd³⁺ ions. Because there were Gd³⁺ ions within the silica shell, the transverse relaxivity increased 7-fold from 97 s^–1 mM^–1 of Fe₃O₄ to 681 s^–1 mM^–1 of Gd³⁺-chelated Fe₃O₄@SiO₂ nanoparticles with r₂/r₁ = 486. The large transversal relaxivity of the Gd³⁺-chelated Fe₃O₄@SiO₂ nanoparticles had an effective magnetic resonance imaging effect and clearly imaged lymph nodes. Physiological studies of liver, spleen, kidney, and lung tissue in mice infused with these new nanoparticles showed no damage and no cytotoxicity in Kupffer cells, which indicated that Gd³⁺-chelated Fe₃O₄@SiO₂ nanoparticles are biocompatible.