Woo Choul Heo1, Ja Young Park1, Kattel Krishna1, Wenlolg Xu1, Tirusew Tegafaw Mengesha1, Badrul Alam Bony1, Gang Ho Lee1
1Department of Chemistry, Kyungpook National University, Daegu, Korea, Republic of
We reported the synthesis and characterization of ultrasmall gadolinium oxide nanoparticles. In this work, the ultrasmall gadolinium oxide nanoparticles with an average d of 1 nm having r1 of 9.9 s-1 mM-1, which is much larger than those of Gd(III)-chelates. It seems that surface Gd(III) ions in gadolinium oxide nanoparticles cooperatively induce the longitudinal relaxation of the water proton. As a result, this cooperative induction effect accelerates the longitudinal relaxation of the water proton, providing a larger r1 than Gd(III)-chelates. We address this by carefully examining the d dependence of r1. We finally took in vivo T1 MR images of a rat with a brain tumor by using D-glucuronic acid coated ultrasmall gadolinium oxide nanoparticles and observed a clear contrast enhancement in T1 MR images of the tumor after injection.