Leonie E. Paulis1, Igor Jacobs1, Nynke M. van Den Akker2, Bram F. Coolen1, Tessa Geelen1, Klaas Nicolay1, Gustav J. Strijkers1
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 2Department of Cardiology, University of Maastricht, Maastricht, Netherlands
In vivo molecular MRI of ICAM-1 expression on vascular endothelium after ischemia/reperfusion induced myocardial infarction was explored using ICAM-1 targeted paramagnetic liposomes. The contrast agent formulation was optimized to enhance ICAM-1 specific association. Using this formulation, MRI could distinguish low from high levels of cellular ICAM-1 expression in vitro. In addition, under physiological shear stress conditions, ICAM-1 specific binding was observed. In vivo circulation kinetics and biodistribution were determined with MRI and confocal microscopy. In vivo cardiac T1w MRI showed signal enhancement in infarcted myocardium using ICAM-targeted liposomes compared to control lipsomes, which was confirmed by ex vivo microscopy.