Dual-mode T sub(1) and T sub(2) magnetic resonance imaging contrast agent based on ultrasmall mixed gadolinium-dysprosium oxide nanoparticles: synthesis, characterization, and in vivo application

• Published in: Nanotechnology 2015-09, Vol.26 (36), p.1-13
• Main Authors: Tegafaw, Tirusew, Xu, Wenlong, Ahmad, Wasi, Baeck, Jong Su, Chang, Yongmin, Bae, Ji Eun, Chae, Kwon Seok, Kim, Tae Jeong, Lee, Gang Ho
• Format: Article
• Language: English
• Subjects: Asymptotic properties; Contrast agents; Electron spin; Lanthanides; Magnetic moment; Magnetic resonance imaging; Nanoparticles; Oxides
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/26/36/365102

A new type of dual-mode T sub(1) and T sub(2) magnetic resonance imaging (MRI) contrast agent based on mixed lanthanide oxide nanoparticles was synthesized. Gd super(3+) ( super(8)S sub(7/2)) plays an important role in T sub(1) MRI contrast agents because of its large electron spin magnetic moment resulting from its seven unpaired 4f-electrons, and Dy super(3+) ( super(6)H sub(15/2)) has the potential to be used in T sub(2) MRI contrast agents because of its very large total electron magnetic moment: among lanthanide oxide nanoparticles, Dy sub(2)O sub(3) nanoparticles have the largest magnetic moments at room temperature. Using these properties of Gd super(3+) and Dy super(3+) and their oxide nanoparticles, ultrasmall mixed gadolinium-dysprosium oxide (GDO) nanoparticles were synthesized and their potential to act as a dual-mode T sub(1) and T sub(2) MRI contrast agent was investigated in vitro and in vivo. The D-glucuronic acid coated GDO nanoparticles (d sub(avg) = 1.0 nm) showed large r sub(1) and r sub(2) values (r sub(2)/ r sub(1) [asymptotically =] 6.6) and as a result clear dose-dependent contrast enhancements in R sub(1) and R sub(2) map images. Finally, the dual-mode imaging capability of the nanoparticles was confirmed by obtaining in vivo T sub(1) and T sub(2) MR images.