Abstract 16334: Molecular Imaging of Atherosclerotic Plaque via Profilin-1 Antibody Labeled PEI-Fe3O4 Magnetic Nanoparticles
Background and aims: Atherosclerosis and its complications are the major causes of mortality worldwide. It is reported recently that profilin-1, an intracellular actin-binding protein, plays a pivotal role on progression of atherosclerotic lesion. The rationale of our study was to resemble a novel molecular imaging nano-probe to assess atherosclerotic plaque vulnerability noninvasively by magnetic resonance imaging (MRI).
Methods: Rabbit atherosclerotic plaque was induced in femoral artery by balloon injury and feeding with containing 1.5% cholesterol diet. To construct MRI probe, profilin-1 antibody was conjugated to PEI-Fe3O4 nanoparticles by carboxyl and amine condensation reaction. UV (ultraviolet)-Vis absorption spectroscopy was applied to examine the conjugate efficiency at PH conditions. The signal intensity of plaques in 38 lesions from 15 rabbits were detected with 3.0T MRI T2WI . In order to determine the correlation between MRI signal intensity and plaque vulnerability, all the lesions observed by MRI post probe injection were divided into hypointense plaque (HIP) or non-hypointense plaque (non-HIP) group, and plaque vulnerability was further confirmed by intravenous ultrasound (IVUS), optical coherence tomography (OCT) imaging and histological analysis .
Results: It was revealed that conjugate efficiency of probe was 79.8% at reaction system of PH=8.0, higher that other conditions. MRI results showed that of all the lesions, 56% were HIP and 44% were non-HIP. IVUS and OCT imaging reveled that the frequency of lipid-rich core (>40%) and thin-cap fibroatheroma (<65μm) were significantly higher in HIP group than those in the non-HIP group (67% vs. 33%, p<0.05; 72% vs. 28%, p<0.05). Histological analysis was consistent with these results on the whole.
Conclusion: Profilin-1-PEI-Fe3O4 nanoparticles is a novel potential molecular imaging probe for noninvasive assessment of atherosclerotic plaque characteristics by MRI.
- © 2013 by American Heart Association, Inc.