文献类型：期刊文献

英文题名：Gadolinium complexes of macrocyclic diethylenetriamine-N-oxide pentaacetic acid-bisamide as highly stable MRI contrast agents with high relaxivity

作者：Xu, Kehan[1];Xu, Na[1];Zhang, Beibei[1];Tang, Weijun[2];Ding, Yun[1];Hu, Aiguo[1]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai Key Lab Adv Polymer Mat, Shanghai 200237, Peoples R China;[2]Fudan Univ, Dept Radiol, Huashan Hosp, Shanghai 200040, Peoples R China

年份：2020

卷号：49

期号：26

起止页码：8927

外文期刊名：DALTON TRANSACTIONS

收录：;EI(收录号：20203709152308);WOS:【SCI-EXPANDED(收录号:WOS:000552458700012)】；

基金：The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China (21274042 and 21503078), the Fundamental Research Funds for the Central Universities (22221818014), and the Shanghai Leading Academic Discipline Project (B502). AH thanks the "Eastern Scholar Professorship" support from the Shanghai local government.

语种：英文

外文关键词：Magnetic resonance imaging - Gadolinium compounds - Hydration - Ligands - Stability criteria

摘要：Gadolinium(III) complexes are generally considered efficient magnetic resonance imaging (MRI) contrast agents (CAs) and widely used in clinical applications. High relaxivity and stability are two essential criteria for a Gd(iii)-complex to be used as a MRI-CA. One crucial strategy to achieve high relaxivity for small molecular Gd(III)-based MRI contrast agents is to increase the hydration numberq. Meanwhile, metal complexes with macrocyclic ligands have been proved to inherit high thermodynamic stability and kinetic inertness. Herein, a series of macrocyclic ligands based on diethylenetriamine-N-oxide pentaacetic acid-bisamide were synthesized. Among them, cyclo-DTPA-NO-C6O2 (3d) was the strongest ligand for Gd(iii) as confirmed by experimental results. The hydration number of the Gd-cyclo-DTPA-NO-C6O2 (4d) complex was characterized by luminescence measurements to be 3 and the coordination structure was confirmed with computational simulations. Consequently, the relaxivity of this complex (14.3 mM(-1)s(-1), 1.5 T, 25 degrees C) is about triple that of commercial MRI CAs. The conditional stability constant of the Gd(iii) complex, pGd, calculated from spectrophotometric titration studies, was comparable to that of one of the most stable commercial MRI-CAs, Gd-DTPA (Magnevist (R)). Meanwhile, the kinetic inertness of the complex was even higher than that of Gd-DTPA thanks to its macrocyclic coordination structure.