[Sinerem labeling and MRI tracking of neural stem cells in vivo and in vitro].
OBJECTIVE
To label rat neural stem cells (NSCs) with the complex of Sinerem, the ultrasmall superparamagnetic iron oxide (USPIO), and poly-L-lysine (PLL), and evaluate the feasibility of tracking the labeled cells with magnetic resonance imaging (MRI) in vitro and in vivo.


METHODS
Sinerem was incubated with PLL to obtain the complex of Sinerem-PLL. The mesenchymal stem cells (MSCs) isolated from the bone marrow of SD rats were cultured and induced to differentiate into the neural stem cells. The second-passage cells were cultured overnight with the Sinerem-PLL complex, after which Prussian blue staining and transmission electron microscopy were performed to observe the nanoparticles in the cytoplasm. Cell apoptosis assay was performed to assess the cell viability 1 day, 1 week, and 2 weeks after the labeling. Cell tracking with 4.7 MR system was carried out in vivo and in vitro using T(2)WI and T(2)*WI sequences.


RESULTS
The NSCs could be effectively labeled with Sinerem-PLL complex with the labeling efficiency exceeding 95%. Prussian blue staining showed numerous blue iron particles in the cytoplasm, and under transmission electron microscope, these particles accumulated in the endosomes/lysosomes. The labeling did not significantly affect the cell viability and proliferation. Remarkable low signal density changes of the labeled cells was seen on T(2)WI and T(2)*WI in vivo and in vitro.


CONCLUSIONS
NSCs can be effectively labeled with Sinerem-PLL complex, and MRI can be used to track the labeled cells in vivo and in vitro.
Chen
Zhong-can
ZC
Department of Neurosurgery and Institute of Neuroscience of Guangdong Province, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. chenzhongcan @163.com
Xu
Ru-xiang
RX
Yang
Zhi-jun
ZJ
Fan
Juan
J
Xiu
Jun-gang
JG
Dai
Guang-hui
GH
Jiang
Xiao-dan
XD
Wei
Li
L
Lei
Hao
H
D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D003911:Dextrans / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism; D052203:Ferrosoferric Oxide / Q000378:metabolism*; D008247:Lysosomes / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology; D046529:Microscopy, Electron, Transmission; D009474:Neurons / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D011107:Polylysine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D013997:Time Factors
D003911:Dextrans; D058185:Magnetite Nanoparticles; C097921:ferumoxtran-10; D011107:Polylysine; D052203:Ferrosoferric Oxide