基于动态有机钆纳米颗粒的T_(1)-T_(2)双模态MRI造影剂

Dual-modal MRI T_(1)-T_(2) Contrast Agent Based on Dynamic Organic Gadolinium Nanoparticles

本文设计、合成并测试了一种新型的基于有机钆纳米颗粒的磁共振成像(MRI)造影剂.以1,2-氨基硫醇与氰基的缩合反应为基础,成功合成了粒径在8~23 nm范围内的有机钆纳米颗粒.该有机钆纳米颗粒作为磁共振造影剂时,随着时间的推移,其纵向弛豫率逐渐减弱,横向弛豫率先增强后逐渐减弱,这与钆纳米颗粒粒径增大有关.有机钆纳米颗粒同时存在随时间变化的纵向弛豫和横向弛豫,表明它有望成为一种先进的T_(1)-T_(2)双模态MRI造影剂.

In this work,a new magnetic resonance imaging(MRI)contrast agent based on organic gadolinium(Gd)nanoparticles was designed,synthesized and tested.Based on a biocompatible condensation reaction between 1,2-aminothiol and cyano group,organic Gd nanoparticles with well-controlled diameter in the range of 8~23 nm were successfully synthesized.When used as the MRI contrast agent,the organic Gd-nanoparticles exhibited slowly weakened longitudinal relaxivity with time.Meanwhile,its transverse relaxivity was observed to be enhanced firstly and then gradually weakened,which could be attributed to the diameter increase of the Gd-nanoparticles.The simultaneous existence of time-dependent longitudinal and transverse relaxivities of the organic Gd-nanoparticles suggests their potential to be advanced T_(1)-T_(2) dual-modal contrast agent for MRI.