Multimodal SPION-CREKA peptide based agents for molecular imaging of microthrombus in a rat myocardial ischemia-reperfusion model.

Microthrombosis plays a key role in many cardiovascular diseases. Although it is not difficult to localize thrombus within large or middle-sized vessels, the noninvasive diagnostic regimen for the detection of microthrombus remains scarce. Here we developed a nanoagent by conjucting superparamagnetic iron-oxide nanoparticle with fluorophore and a targeting element, CREKA, a peptide with special affinity for fibrin. In a rat model of myocardial ischemia-reperfusion (MI/R), the multimodal nanoagents were readily and selectively accumulated within microthrombosis, which was detectable by both magnetic resonance and optical imaging modalities. The fibrin-targeted nanoagent could be expected to have utility not only in molecular imaging of fibrin, understanding the mechanisms of microcirculation disorders, but also in targeted therapy with fibrinolytic agents.