Maltol-Functionalized Fe3O4 Nanoparticles as T2 Magnetic Resonance Imaging Contrast Agents

We present the use of maltol (3-hydroxy-2-methyl-4H-pyran-4one) as a capping ligand for iron oxide nanomaterials. Watersoluble maltol-coated Fe3O4 nanoparticles were synthesized by a reductive one-pot synthesis. The nanoparticles were found to be stable in water, and their superparamagnetic properties enabled their application as ultrahigh field T-2 magnetic resonance imaging (MRI) contrast agents. High r(2) relaxivity and r(2)/r(1) ratios were determined at clinical (B-0 = 3 T) and ultrahigh (B-0 = 9.4 T) fields, making them on par or superior to current iron-oxide based commercial MRI contrast agents. A low cytotoxic re-sponse in three distinct cell types (HUVEC, KB, U343) indicate maltol-coated Fe3O4 nanoparticles are promising T-2 MRI contrast agents.