[Labeling neural stem cells with superparamagnetic iron oxide in vitro and tracking after implantation with MRI in vivo].
OBJECTIVE
To evaluate the feasibility of monitoring the neural stem cells implanted into the brain by the technique of labeling with superparamagnetic iron oxide (SPIO).


METHODS
Neural stem cells were isolated from the cerebral cortex of newborn Wister rats and cultured. SPIO particles and poly-L-lysine were added into the medium to be co-cultured foe one hour. After the formation of neurospheres, Prussian blue staining was conducted and transmission electron microscopy was used to identify the iron particles in these neural stem cells. Sixteen adult female Wistar rats underwent transplantation of labeled neural stem cells into the right side of brain and non-labeled cells were transplanted into the contralateral part as controls. 1, 2, 4, 6, and 7 weeks after the transplantation, MRI examination with the scanning sequences of SE T2WI, FSE T2WI, and GRE T2 * respectively was conducted on the brains of the rats. Four rats at each time point were killed and their brains were taken out to undergo HE staining and Prussian blue staining to track the presence of labeled-cells.


RESULTS
After the addition of SPIO the neurospheres continued to proliferate and differentiate normally. Electron microscopy showed vacuolar structures of different sizes under the cytoplasma membrane within and outside which there were high-density iron particles. Prussian blue staining showed numerous blue stained particles in the cytoplasm of the labeled cells. Remarkable low signal change was seen in the right brain transplanted with labeled cells, especially in the condition of scanning sequence of GRET2. Such change could be seen up to 7 weeks after the transplantation. No signal change was found in the left brain.


CONCLUSIONS
SPIO labeling technique is useful in monitoring the outcome of transplanted neural stem cells.
Jing
Meng
M
Department of Neurosurgery, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, China.
Liu
Xin-quan
XQ
Liang
Peng
P
Li
Chang-yu
CY
Zhang
Xiang-tong
XT
Wang
Dan
D
Luan
Yu
Y
Liu
En-zhong
EZ
D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation; D002478:Cells, Cultured; D005260:Female; D052203:Ferrosoferric Oxide; D007202:Indicators and Reagents / Q000493:pharmacokinetics; D007501:Iron / Q000493:pharmacokinetics*; D008055:Lipids; D008279:Magnetic Resonance Imaging; D036103:Nanotechnology; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D010087:Oxides / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D014162:Transfection / Q000379:methods
D007202:Indicators and Reagents; D008055:Lipids; C086724:Lipofectamine; D010087:Oxides; D007501:Iron; D052203:Ferrosoferric Oxide