High-stability spherical lanthanide nanoclusters for magnetic resonance imaging

Area of Science:

• Coordination Chemistry
• Materials Science
• Medical Imaging

Background:

• High-nuclear lanthanide clusters are promising for MRI contrast agents.
• Developing water-stable, high-nuclear lanthanide clusters is crucial for advancing MRI performance.
• Existing gadolinium chelates face challenges in high-dose administration.

Purpose of the Study:

• To synthesize and characterize novel, highly stable, spherical high-nuclear lanthanide clusters.
• To investigate the potential of these clusters as advanced MRI contrast agents.
• To explore the assembly mechanism of spherical high-nuclear lanthanide clusters.

Main Methods:

• Synthesis of spherical lanthanide clusters Ln32 (Ln = Ho, Gd) using N-methylbenzimidazole-2-methanol (HL) and LnCl3·6H2O.
• Assessment of Ho32 cluster stability in HRESI-MS and varying pH aqueous solutions.
• Evaluation of Gd32 cluster's longitudinal relaxation rate and MRI performance in tumor-bearing mice.

Main Results:

• Two highly water-stable spherical lanthanide clusters, Ho32 and Gd32, were successfully synthesized.
• Ho32 demonstrated exceptional stability under ion bombardment and diverse pH conditions.
• Gd32 exhibited a high longitudinal relaxation rate and superior T1-weighted MRI contrast compared to Gd-DTPA in vivo.
• The assembly mechanism of spherical high-nuclear lanthanide clusters was proposed for the first time.

Conclusions:

• The synthesized high-nuclear lanthanide clusters exhibit remarkable stability and potential for MRI applications.
• Gd32 clusters offer enhanced imaging contrast, paving the way for reduced gadolinium dosage.
• This study represents a significant advancement in the development of stable, high-nuclear lanthanide clusters for advanced MRI.