Core-Shell Fe3O4@C Nanoparticles as Highly Effective T2 Magnetic Resonance Imaging Contrast Agents: In Vitro and In Vivo Studies

Abstract

Magnetite nanoparticles (Fe3O4 NPs) have been intensively investigated because of their potential biomedical applications due to their high saturation magnetization. In this study, core–shell Fe3O4@C NPs (core = Fe3O4 NPs and shell = amorphous carbons, davg = 35.1 nm) were synthesized in an aqueous solution. Carbon coating terminated with hydrophilic –OH and –COOH groups imparted excellent biocompatibility and hydrophilicity to the NPs, making them suitable for biomedical applications. The Fe3O4@C NPs exhibited ideal relaxometric properties for T2 magnetic resonance imaging (MRI) contrast agents (i.e., high transverse and negligible longitudinal water proton spin relaxivities), making them exclusively induce only T2 relaxation. Their T2 MRI performance as contrast agents was confirmed in vivo by measuring T2 MR images in mice before and after intravenous injection.