Water‐dispersible Gadolinium Oxide Nanoplates as an Effective Positive Magnetic Resonance Imaging Contrast Agent

Abstract

Gadolinium oxide (Gd 2 O 3 ) nanoplates have been successfully synthesized by thermal decomposition method in the presence of oleic acid and oleylamine as surfactants. As a result, the nanoplates have average edge length and thickness around 10 nm and 1.1 nm, respectively. The hydrophobic OA/OM capped Gd 2 O 3 nanoplates were encapsulated with amphiphilic poly (maleic anhydride-alt-1-octadecene) polymer (PMAO) for phase transfer into aqueous media. The obtained Gd 2 O 3 @PMAO showed a hydrodynamic size of 32 nm with good dispersion in water solvent and stable in wide range of pH (pH = 2 � 11) and at electrolyte concentrations as high as NaCl 380 mM. In addition, the in vitro toxicity tests confirmed the biocompatibility of Gd 2 O 3 @PMAO nanoplates. The magnetic resonance imaging (MRI) result exhibited the r 1 of Gd 2 O 3 @PMAO nanoplates (16.95 mM À 1 s À 1 ) is four times higher than that of clinically used Gd-DTPA. These results suggest that the PMAO coated -Gd 2 O 3 nanoplates are potential T 1 contrast agents for in vivo MRI application.