Blood Clearance of Citric Acid-Coated Superparamagnetic Iron Oxide Nanoparticles in Rats - a Pilot Study.

Superparamagnetic iron oxide nanoparticles are primarily utilized for different biomedical applications such as magnetic resonance imaging (MRI), hyperthermia, cancer treatment, targeted delivery of drugs or genes and biosensors. Nanoparticles are interesting due to their unique proprieties together with minor side effects. It is essential to determine the blood clearance of superparamagnetic nanoparticles (SPIONs) for in vivo biomedical applications, to ensure their optimum clinical use. The purpose of this study was to evaluate the elimination kinetic of citric-acid iron oxide nanoparticles in blood via intravenous injection in rats. Animals were blood sampled at different time intervals, ranging from 30 minutes to 24 hours after injection. The decay of SPIONs in blood was analyzed using electron paramagnetic resonance (EPR) technique. The results suggest that the injected iron oxide nanoparticles are rapidly cleared from circulation, with half-life of elimination process from the bloodstream about 14.06 minutes.