In vivo cardiac magnetic resonance imaging of superparamagnetic iron oxides-labeled mesenchymal stem cells in swines / 中华心血管病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the feasibility of magnetic resonance imaging (MR) on detecting transplanted nanometer small superparamagnetic iron oxides (SPIO) labeled mesenchymal stem cells (MSCs) in swine model with acute myocardial infarction (MI).</p><p><b>METHODS</b>MSCs isolated from swine were incubated with nanometer SPIO for 24 hours and the third-passage MSCs were labeled with DNA dye 4'-6-diamidino-2-phenylindole (DAPI) and aliphatic red fluorescent dye PKH(26)-GL. Presence of small particles of SPIO in MSCs was assessed by Prussian Blue staining and electron microscopy. Three animals in each group received SPIO-labeled MSCs (5 x 10(5); 1 x 10(6); 2 x 10(6)) and MSCs without SPIO (1 x 10(6)) injections into the infarcted myocardium approximately 1 hour following left anterior descending coronary artery. MRI (1.5-T) was performed 20 to 24 hours post infarction in all animals and the animals were subsequently sacrificed for histology 1 hour post MRI.</p><p><b>RESULTS</b>In vitro Prussian Blue staining and electron microscopy examination revealed numerous iron particles in the cytoplasm of MSCs. Low signal intensity spots with the scanning T(2)(*)WI-Flash 2d sequence were detected in all SPIO-MSCs but not in SPIO-negative-MSCs injected myocardial sites in vivo with the clinical 1.5 T scanner. Prussian blue, DAPI and PKH(26) positive cells were detected histologically in sections corresponding to low signal intensity spots area shown on MRI.</p><p><b>CONCLUSION</b>Magnetically labeled MSCs transplanted in myocardial ischemia area of swine can be visualized in vivo with a clinical 1.5-T MRI and could be used for tracking SPIO-MSCs clinically.</p>