Water-soluble d-glucuronic acid coated ultrasmall mixed Ln/Mn (Ln = Gd and Dy) oxide nanoparticles and their application to magnetic resonance imaging

Abstract

Ultrasmall lanthanide oxide nanoparticles are promising materials as new magnetic resonance imaging (MRI) contrast agents because of their appreciable longitudinal (r₁) or transverse (r₂) water proton relaxivities at ultrasmall particle diameters. Two systems of D-glucuronic acid coated ultrasmall Ln/Mn (Ln = Gd and Dy) oxide nanoparticles with an average particle diameter of 2.0 nm were explored. The D-glucuronic acid coated ultrasmall Gd/Mn oxide nanoparticles showed strong positive contrast enhancements in 1.5 tesla T₁ MR images while the D-glucuronic acid coated ultrasmall Dy/Mn oxide nanoparticles showed appreciable negative contrast enhancements in 1.5 tesla T₂ MR images, proving their potential as T₁ and T₂ MRI contrast agents, respectively.