Paramagnetic ultrasmall Ho2O3 and Tm2O3 nanoparticles: characterization of r2 values and in vivo T2 MR images at a 3.0 T MR field
Abstract
Paramagnetic ultrasmall Ho2O3 and Tm2O3 nanoparticles (davg = ∼2.1 nm) grafted with various hydrophilic and biocompatible ligands such as poly(ethylene glycol) diacid (Mn = 250 and 600 amu) and polyacrylic acid (Mw = 1800 amu) were synthesized via a one-pot polyol method. Appreciable transverse (r2) and negligible longitudinal (r1) water proton spin relaxivity values were observed for all nanoparticle samples. The r2 values increased with increasing nanoparticle magnetic moment and decreased with increasing ligand size. Owing to the aforementioned r1 and r2 values, the nanoparticle samples exhibited appreciable negative contrast enhancements in in vivo T2 magnetic resonance (MR) images at a 3.0 T MR field after intravenous injection, demonstrating their potential as efficient T2 MRI contrast agents.
- This article is part of the themed collection: Celebrating materials science in Japan and South Korea