The Evolution of Iron Oxide Nanoparticles as MRI Contrast Agents

While the use of iron oxide nanoparticles as magnetic resonance contrast agents for clinical imaging is established, they are more recently experiencing renewed interest as alternatives to gadolinium-based contrast agents. Ultra-small iron oxide nanoparticles have unique pharmacokinetics, metabolic and imaging properties. These properties have led to improved techniques for imaging a variety of vascular, oncologic and inflammatory conditions with iron oxide nanoparticles. Current research efforts are aimed at harnessing the characteristics of these nanoparticles to advance magnetic resonance imaging techniques and explore new therapeutic potentials. While there are some limitations to the use of iron oxide nanoparticles, including allergies to parenteral iron and iron storage disorders, the practicable applications for these agents will continue to expand. The purpose of this review is to provide a brief overview of the history and synthesis of iron oxide nanoparticles, their current applications in clinical imaging and their prospective clinical applications.