[In vivo cardiac magnetic resonance imaging of superparamagnetic iron oxides-labeled mesenchymal stem cells in swines].
OBJECTIVE
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).


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Huang
Zhe-Yong
ZY
Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai 200032, China. jbge@zshospital.net
Ge
Jun-Bo
JB
Yang
Shan
S
Zhang
Shao-Heng
SH
Huang
Rong-Chong
RC
Jin
Hang
H
Zeng
Meng-Su
MS
Sun
Ai-Jun
AJ
Qian
Ju-Ying
JY
Zou
Yun-Zeng
YZ
D000818:Animals; D015415:Biomarkers; D004195:Disease Models, Animal; D052203:Ferrosoferric Oxide; D008279:Magnetic Resonance Imaging / Q000379:methods*; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology; D009203:Myocardial Infarction / Q000473:pathology / Q000601:surgery*; D032383:Myocytes, Cardiac; D053758:Nanoparticles; D013552:Swine
D015415:Biomarkers; D052203:Ferrosoferric Oxide