[In vivo tracking of bone marrow mesenchymal stem cells labeled with superparamagnetic iron oxide after cerebral ischemia in rats by magnetic resonance imaging].
OBJECTIVE
To explore the feasibility of in vivo tracking of bone marrow mesenchymal stem cells (BMSCs) labeled with superparamagnetic iron oxide (SPIO) by magnetic resonance imaging (MRI) in rats after cerebral ischemia, and to analyze the influence of stem cell therapy on the volume of cerebral infarction.


METHODS
The samples of rat bone marrow were collected. BMSCs separated by density gradient centrifugation were cultivated and harvested until the third passage. BMSCs were labeled with SPIO, which was mixed with poly-L-lysine. The labeling efficiency was evaluated by Prussian blue staining. Transient middle cerebral arterial occlusion (MCAO) was performed successfully in 18 adult Sprague-Dawley rats that scored from 6 to 12 by the modified neurological severity test. The 18 rats were then randomly divided into group A, B, and C, with 6 rats in each group and Group C was regarded as control group. BMSCs were injected into the contralateral cortex of ischemia in group A, ipsilateral corpora striata in group B, while D-Hank's solution was injected into ipsilateral corpora striata (group C) 24 hours after MCAO. MRI was performed 1 day after MCAO, 1 day and 14 days after transplantation. The volume of infarcted brain tissue was measured and analyzed. Prussian blue staining of brain tissues was performed to identify the migration of BMSCs.


RESULTS
The labeling efficiency of BMSCs with SPIO was 96%. The transplanted BMSCs migrated to the ischemic hemisphere along the corpus callosum and to the border of the infarction, which was confirmed by MRI and Prussian blue staining. The changes of infarction volume were not significantly different among these three groups.


CONCLUSIONS
MRI is feasible for in vivo tracking of BMSCs labeled with SPIO in rats. The stem cell therapy may not be able to affect the volume of cerebral infarction.
Wei
Jun-Ji
JJ
Department of Neurosurgery, PUMC Hospital, CAMS and PUMC, Beijing 100730, China.
Wang
Ren-Zhi
RZ
Lu
Jing-Jing
JJ
Wang
Yu
Y
Fan
Xiao-Tong
XT
Feng
Feng
F
Ma
Wen-Bin
WB
Yang
Yi
Y
Li
Gui-Lin
GL
Dou
Wan-Chen
WC
Jin
Zheng-Yu
ZY
Kong
Yan-Guo
YG
D000818:Animals; D001921:Brain / Q000473:pathology; D002478:Cells, Cultured; D003911:Dextrans; D004195:Disease Models, Animal; D005240:Feasibility Studies; D052203:Ferrosoferric Oxide; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling / Q000379:methods*; D020521:Stroke / Q000473:pathology / Q000601:surgery*
D003911:Dextrans; D058185:Magnetite Nanoparticles; C065507:ferumoxides; D052203:Ferrosoferric Oxide