Imaging of carotid artery inflammatory plaques with superparamagnetic nanoparticles and an external magnet collar

nanoparticles with an organosilica layer, which was followed by modification with polyethylene glycol. It was verified that the resultant nanocomposite possesses a higher structural stability, excellent dispersivity, separability, as well as biosafety. More importantly, the strong magnetism was preserved, making it possible to attract the SNPs with an external magnetic field and achieve a target concentration within the lesion. Moreover, an in vitro magnetic collar, designed to produce a stable magnetic field around the superficial common carotid arteries was introduced. The SNPs particles in the blood flow were slowed down by the collar, their motion direction was changed, and they were captured by the inflammatory cells in the plaque. The effectiveness and feasibility of the particles were evaluated via testing the MRI performance on histological levels with a rat carotid plaque model. The SNPs that were concentrated and accumulated in the plaque were verified to present an evident, negative enhancement in the Proton Density-T2 (PD-T2) sequence images. Therefore, it was demonstrated that the superparamagnetic nanoparticles have great potential as an MRI contrast agent to detect early stage carotid artery inflammatory plaques with an external magnetic collar.