Synthesis of Iron Nanoparticles for Enhanced MRI Contrast Agents

Abstract

Iron nanoparticles (metal and oxides) are being heavily researched for biomedical applications including hyperthermia therapies and MRI contrast agents. Synthesizing metal iron nanoparticles would take advantage of its high room temperature saturation magnetization, shorter relaxation time, and large magnetic moment to improve MRI technologies by increasing resolution and providing a substitute to patients unable to use current Gd contrast agents. Preserving the edge iron metal nanoparticles have over their iron oxide counterparts is particularly difficult as iron metal is extremely susceptible to oxidation. Iron metal nanoparticles have been previously synthesized, but the methods used to prevent oxidation rendered the nanoparticles non- biocompatible. The goal of this work was to produce a metal iron nanoparticle to be used as an MRI contrast agent. Iron metal nanoparticles and superparamagnetic iron oxide nanoparticles were successfully synthesized. The samples are a result of three batches created using a reduction method with various coatings and techniques. These results were confirmed by Mössbauer and TEM. Cell toxicity was evaluated to ensure the biocompatibility required for medical applications. The iron metal sample was evaluated three years post synthesis to determine the rate of degradation. It was found to have mostly oxidized with some remnants of iron metal. This result is significant in that it did not completely oxidize; this verifies the stability of the coated nanoparticles in air.