Water-soluble ultra-small manganese oxide surface doped gadolinium oxide (Gd₂O₃@MnO) nanoparticles for MRI contrast agent

We have developed ultra-small gadolinium oxide (Gd₂O ₃) nanoparticles, which are surface-doped with manganese oxide (MnO) (abbreviated as Gd₂O₃@MnO). The surface-doped nanoparticles ranged from 1 to 2 nm in diameter. They were further coated with hydrophilic biocompatible lactobionic acid. In-vitro tests of the sample solution indicated clear dose-dependent contrast enhancements in both T ₁ and T₂ map images, showing that the nanoparticles may be used as both T₁ and T₂ MRI contrast agents. Their performance as a T1 MRI contrast agent was proved in vivo through T1 MR images of a mouse.