Lanthanoid endohedral metallofullerenols for MRI contrast agents
Lanthanoid endohedral metallofullerenols for MRI contrast agents
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DOI：
10.1021/ja027555
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发表时间：
2003-04-09
影响因子：
15
通讯作者：
Shinohara, H
中科院分区：
文献类型：
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作者：
Kato, H;Kanazawa, Y;Shinohara, H
水溶性多羟基镧系元素（La、Ce、Gd、Dy和Er）内嵌金属富勒烯（金属富勒烯醇，M@C-82（OH）（n））已经合成并表征用于磁共振成像（MRI）造影剂。所观察到的金属富勒烯醇的水质子的纵向和横向弛豫率r（1）和r（2）分别在0.8 - 73和1.2 - 80（sec（-1）mM（-1））的范围内，这显著高于相应的镧系元素-DTPA螯合物的弛豫率。在这些金属富勒烯醇中，Gd@C-82（OH）（n）表现出最高的r（1）和r（2）值，这与我们以前的结果一致。所观察到的大的r（1）的电流金属富勒烯醇可以主要归因于偶极-偶极弛豫连同整体分子旋转运动的大幅减少。大的r（2），除了Gd-金属富勒烯醇，已被归因于所谓的居里自旋弛豫。还进行了MRI体模研究，结果与这些结果一致。金属富勒烯醇将是未来具有更高质子弛豫率的MRI造影剂的理想模型。
Water-soluble multi-hydroxyl lanthanoid (La, Ce, Gd, Dy, and Er) endohedral metallofullerenes (metallofullerenols, M@C-82(OH)(n)) have been synthesized and characterized for the use of magnetic resonance imaging (MRI) contrast agents. The observed longitudinal and transverse relaxivities for water protons, r(1) and r(2), of the metallofullerenols are in the range 0.8-73 and 1.2-80 (sec(-1)mM(-1)), respectively, which are significantly higher than those of the corresponding lanthanoid-DTPA chelate complexes. Among these Gd-metallofullerenols, Gd@C-82(OH)(n) has exhibited the highest r(1) and r(2) values in consistent with our previous results. The observed large r(1) of the current metallofullerenols can mainly be ascribed to the dipole-dipole relaxation together with a substantial decrease of the overall molecular rotational motion. The large r(2), except for the Gd-metallofullerenols, have been attributed to the so-called Curie spin relaxation. The MRI phantom studies are also performed and are consistent with these results. The metallofullerenols will be an ideal model for future MRI contrast agents with higher proton relaxivities.