Effect of Polyol Chain Length on Proton Relaxivity of Gadolinium Oxide Nanoparticles for Enhanced Magnetic Resonance Imaging Contrast

Abstract

We present the impact of surface modifications on the magnetic resonance imaging (MRI) contrast enhancement abilities of gadolinium oxide nanoparticles. A series of gadolinium oxide nanoparticles surface-coated with polyols of different reductive abilities such as diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (TeEG), and polyethylene glycol (PEG 200) were synthesized. Particle sizes of synthesized Gd2O3 nanoparticles were found to be in correlation with the chain length of glycol. An enhancement in the in vitro and ex vivo relaxivity of Gd2O3 nanoparticles was revealed with the increase in glycol chain length. Among the various nanosystems, PEG-Gd2O3 has the highest in vitro and ex vivo relaxivities and excellent biocompatibility as revealed from cellular cytotoxicity experiments. The enhancement in MR contrast with glycol chain length can be attributed to the increase in surface hydrophilicity, and its modulation can be exploited as a novel strategy for enhancing the MRI contrast of gadolinium-based contrast agents. © 2019 American Chemical Society.