Noncovalent functionalization of carbon nanotubes with amphiphilic Gd3+ chelates:: Toward powerful T1 and T2 MRI contrast agents
Noncovalent functionalization of carbon nanotubes with amphiphilic Gd3+ chelates:: Toward powerful T1 and T2 MRI contrast agents
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DOI：
10.1021/nl072509z
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发表时间：
2008-01-01
期刊：
影响因子：
10.8
通讯作者：
Scherman, Daniel
中科院分区：
文献类型：
--
作者：
Richard, Cyrille;Doan, Bich-Thuy;Scherman, Daniel
以市售硬脂酸为原料合成了两亲性钆螯合物（GdL）。制备了不同浓度（1 ~ 1 μ M）的配合物水溶液，并将其吸附在多壁碳纳米管上。所得到的悬浮液在几天内是稳定的，并且在磁共振成像（MRI）造影剂应用方面具有特征。纵向水质子弛豫度r(1)在20、300和500兆赫下测量。r(1)值与GdL浓度有很强的依赖性，特别是在低场下。正如Solomon-Bloembergen-Morgan理论所预测的那样，弛豫率随着电场的增大而减小。横向水质子弛豫时间T-2也被测量过，它实际上与频率和GdL浓度无关。在300兆赫下对小鼠进行了体内可行性MRI研究。在将功能化纳米管悬浮液注入小鼠腿部肌肉后，可以很好地观察到负对比。
An amphiphilic gadolinium (III) chelate (GdL) was synthesized from commercially available stearic acid. Aqueous solutions of the complex at different concentrations (from 1 mM to 1 mu M) were prepared and adsorbed on multiwalled carbon nanotubes. The resulting suspensions were stable for several days and have been characterized with regard to magnetic resonance imaging (MRI) contrast agent applications. Longitudinal water proton relaxivities, r(1), have been measured at 20, 300, and 500 MHz. The r(1) values show a strong dependence on the GdL concentration, particularly at low field. The relaxivities decrease with increasing field as it is predicted by the Solomon-Bloembergen-Morgan theory. Transverse water proton relaxation times, T-2, have also been measured and are practically independent of both the frequency and the GdL concentration. An in vivo feasibility MRI study has been performed at 300 MHz in mice. A negative contrast could be well observed after injection of a suspension of functionalized nanotubes into the muscle of the leg of the mouse.