Nanoparticle-based chemical exchange saturation transfer (CEST) agents
Nanoparticle-based chemical exchange saturation transfer (CEST) agents
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DOI：
10.1002/nbm.2974
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发表时间：
2013-07-01
影响因子：
2.9
通讯作者：
Aime, Silvio
中科院分区：
文献类型：
--
作者：
Castelli, Daniela Delli;Terreno, Enzo;Aime, Silvio
化学交换饱和转移（CEST）试剂的频率编码特性使它们在MRI造影剂中处于独特的位置，因为它允许在同一张MR图像中显示更多的试剂，并使建立创新的MRI反应剂成为可能。分子CEST试剂（抗磁性或顺磁性）所显示的敏感性问题已经通过设计具有大量可交换质子的纳米粒子基CEST试剂来解决，从而确保了大的饱和转移水平。几种系统已被考虑，即超分子加合物，树状大分子，胶束和脂质体负载CEST试剂（在大多数情况下，顺磁性CEST试剂）。一个特别敏感的系统是由脂质体组成的脂质体，其内部的水共振被顺磁性镧系化合物的共同存在所转移。可交换的质子池由脂质体内腔中包含的所有水分子表示（106-108）。尽管体外实验已经取得了很好的结果，但在体内的翻译似乎在一定程度上受到了这些颗粒在给药活体动物时所表现出的特殊行为的阻碍。版权所有：John Wiley & Sons， Ltd。
The frequency-encoding property of chemical exchange saturation transfer (CEST) agents places them in a unique position among the MRI contrast agents, as it allows the visualization of more agents in the same MR image, as well as making it possible to set up innovative MRI-responsive agents. The sensitivity issue shown by molecular CEST agents (either diamagnetic or paramagnetic) has been tackled with the design of nanoparticle-based CEST agents endowed with a large number of exchangeable protons that ensure large saturation transfer levels. Several systems have been considered, namely supramolecular adducts, dendrimers, micelles and liposomes loaded with CEST agents (in most cases, paramagnetic CEST agents). A particularly sensitive system is represented by lipoCEST agents, consisting of liposomes whose inner water resonance is shifted by the co-presence of paramagnetic lanthanide complexes. The exchangeable pool of protons is represented by all the water molecules contained in the inner liposome cavity (106-108). Although in vitro work has provided excellent results, in vivo translation appears to be hampered to some extent by the peculiar behavior shown by these particles on administration to living animals. Copyright (c) 2013 John Wiley & Sons, Ltd.