Water-Soluble MnO Nanocolloid for a Molecular T1 MR Imaging: A Facile One-Pot Synthesis, In vivo T1 MR Images, and Account for Relaxivities
Water-Soluble MnO Nanocolloid for a Molecular T1 MR Imaging: A Facile One-Pot Synthesis, In vivo T1 MR Images, and Account for Relaxivities
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DOI：
10.1021/am100641z
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发表时间：
2010-10-01
影响因子：
9.5
通讯作者：
Lee, Gang Ho
中科院分区：
文献类型：
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作者：
Baek, Myung Ju;Park, Ja Young;Lee, Gang Ho
一种水溶性MnO纳米胶体（即，D-葡萄糖醛酸包覆的MnO纳米颗粒）。MnO纳米胶体中的MnO纳米颗粒被生物相容性和亲水性的D-葡萄糖醛酸包覆，并且其粒径几乎是单分散的，范围为2至3 nm。MnO纳米胶体的平均流体动力学直径估计为5 nm。MnO纳米颗粒在低至T = 3 K时几乎是顺磁性的。MnO纳米胶体显示出高的纵向水质子弛豫率r（1），= 7.02 s（-1）mM（-1），r（2）/r（1），比率为6.83，这是由于Mn（II）离子的五个未配对S-态电子（S = 5/2）以及MnO纳米颗粒的高表面与体积比。获得了各种器官的高对比度体内T-I，MR图像，显示MnO纳米胶体作为敏感的T-I，MRI造影剂的能力。建议的控制纳米胶体的r（1）和r（2）弛豫率的三个关键参数（即，金属离子的S值、自旋结构和纳米颗粒的表面与体积比）成功地解释了MnO纳米胶体的所观察到的r（1）和r（2）弛豫率。
A facile one-pot synthesis of a water-soluble MnO nanocolloid (i.e., D-glucuronic acid-coated MnO nanoparticle) is presented. The MnO nanoparticle in the MnO nanocolloid was coated with a biocompatible and hydrophilic D-glucuronic acid, and its particle diameter was nearly monodisperse and ranged from 2 to 3 nm. The average hydrodynamic diameter of the MnO nanocolloid was estimated to be 5 nm. The MnO nanoparticle was nearly paramagnetic down to T = 3 K. The MnO nanocolloid showed a high longitudinal water proton relaxivity of r(1), = 7.02 s(-1) mM(-1) with the r(2)/r(1), ratio of 6.83 due to five unpaired S-state electrons of Mn(II) ion (S = 5/2) as well as a high surface to volume ratio of the MnO nanoparticle. High contrast in vivo T-1, MR images were obtained for various organs, showing the capability of the MnO nanocolloid as a sensitive T-1, MRI contrast agent. The suggested three key-parameters which control the r(1) and r(2) relaxivities of nanocolloids (i.e., the S value of a metal ion, the spin structure, and the surface to volume ratio of a nanoparticle) successfully accounted for the observed r(1) and r(2) relaxivities of the MnO nanocolloid.