The effectiveness of iron oxide nanoparticles, which conjugate with various biomolecules, has been studied previously in investigations of novel therapeutic actions and drug delivery, for example, in blood purification therapy and drug treatments for cancer and hyperthermia. [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] According to Bouhlel et al, 26 the mannose receptors of M2 macrophages are more abundantly expressed in pathological tissues of atherosclerotic lesions than in the adjacent zone. Therefore, we focused on mannan-dextran-coated USPIO (DM-USPIO), prepared in-house by adding alkalitreated mannan to dextran-coated USPIO (D-USPIO). Our working hypothesis posited that the addition of mannan to D-USPIO would facilitate its uptake by macrophage-rich atherosclerotic plaques. Here, we performed MRI and histopathological studies to compare the uptake of DM-USPIO with that of D-USPIO in atherosclerotic plaques of rabbits.