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.

Iron Oxide Nanoparticles Biodistribution in an Experimental Pig Model - A New Approach for Delivery and Imaging.

Iron oxide nanoparticles (IONs) are of great interest in medicine, with great potential for imaging diagnostics, as well as therapeutic. Biomedical applications of IONs have been suggested for magnetic resonance imaging (MRI), with two available contrast agents on the market. However, new developments in biocompatibility and biodistribution are necessary as many new physiochemical features of coatings have been proposed for a good safety profile. MATERIALS AND METHODS: Our study objective was to assess a different setting in terms of biodistribution of IONs coated with citric acid on an experimental pig model, based on EUS-guided portal vein (PV) injection. Four pigs were subjected to EUS procedures and portal vein injection of an IONs solution. All animals were kept under surveillance for the next 24 hours and euthanized. Necropsy was performed and their organs were harvested, visualized with a 3T MRI scanner and sent to pathological examination. RESULTS: All pigs had no change in their behavior and no signs of complications were encountered. There were no problems in identifying the pig's PV under EUS-guidance. The IONs solution was clearly visualized on ultrasound live imaging, during EUS-injection. MRI and histopathological data confirmed all the deposits using Prussian Blue staining. CONCLUSIONS: This paper comes forward as a first phase of assessing new future therapeutic options and their distribution within the main organs depending on their characteristics. In our opinion this new distribution option has a strong incentive to the research of therapeutic and imaging areas and is worthy of further appraisal.