高灵敏度化学交换饱和转移磁共振分子影像探针的构建及应用

项目名称： 高灵敏度化学交换饱和转移磁共振分子影像探针的构建及应用

项目编号： No.21503141

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 曾剑峰

作者单位： 苏州大学

项目金额： 21万元

中文摘要： 化学交换饱和转移是一种新型的磁共振成像技术，不仅具有传统磁共振成像安全、无创、高空间分辨率的优点，同时还可区分不同的造影剂，实现pH值、温度等参数的成像检测，因此在肿瘤诊断方面具有广阔的应用前景。然而，受限于造影剂质子化学位移差小、交换速率慢、质子数目少等原因，该成像技术的灵敏度仍有待于进一步提高。本项目拟以Fe3O4纳米颗粒为核心，通过在纳米颗粒表面修饰具有高质子交换速率的精氨酸来构建一种新型的造影剂，一方面利用Fe3O4纳米颗粒巨大的磁矩提高造影剂质子的化学位移差，另一方面利用纳米颗粒表面较多的结合位点提高单个造影剂单元中可交换质子的数目，以期大大提高化学交换饱和转移磁共振造影剂的灵敏度，重点揭示Fe3O4纳米颗粒尺寸、饱和磁化强度与精氨酸质子化学位移之间的关系规律，为设计和制备高灵敏度化学交换饱和转移磁共振分子影像探针奠定理论和实验基础。

中文关键词： 磁共振成像；化学交换饱和转移；磁性纳米颗粒；分子影像探针

英文摘要： Chemical exchange saturation transfer (CEST) is a new type of magnetic resonance imaging (MRI) technology. It not only possesses the advantages of safe, noninvasive, and high spatial resolution, which the traditional MRI has, but also can distinguish different kinds of MRI contrast agent and realize the imaging detection of pH and temperature. So CEST shows broad application prospects in tumor diagnosis. However, the sensitivity of CEST still need to be further improved due to the limitation of small chemical shift difference, slow proton exchange rate, and less proton number of contrast agent. In this proposal, arginine with fast proton exchange rate will be conjugated to the suface of Fe3O4 nanoparticle for constructing a new kind of contrast agent. On the one hand, the large magnetic moment of Fe3O4 nanoparticle can enhance the chemical shift difference of contrast agent, on the other hand, the nanoparticle can provide more binding sites and thus increase the proton number of each contrast agent unit, and thus improve the sensitivity of CEST imaging. The relationship between particle size of Fe3O4, saturation magnetization of Fe3O4, and chemical shift of arginine will be revealed. It is expected that the research results of this proposal will be potentially helpful for designing and preparation of high sensitivity CEST molecular imaging probes.

英文关键词： Magnetic Resonance Imaging;Chemical Exchange Saturation Transfer;Magnetic Nanoparticle;Molecular Imaging Probe