[Effect of superparamagnetic iron oxide labeling on neural stem cell survival and proliferation].
OBJECTIVE
To study the effect of superparamgnetic iron oxides (ferumoxides) on the survival and proliferation of neural stem cells (NSCs) and determine the optimal ferumoxides concentration for labeling.


METHODS
Bone marrow stromal cells (BMSCs) were obtained from rat femoral marrow and cultured in vitro to induce their differentiation into NSCs. Ferumoxides labeling of the NSCs was performed with different final concentrations of ferumoxides, and the labeling efficiency and viability of the labeled NSCs were evaluated by Prussian blue staining, MTT assay, flow cytometry and transmission electron microscope.


RESULTS
The NSCs could be effectively labeled with ferumoxides with a labeling efficiency of around 90%. Prussian blue staining showed numerous fine granules with blue staining in the cytoplasm of the labeled NSCs, and the intensity of the blue staining was in positive correlation with the ferumoxide concentration for labeling. Transmission electron microscopy of the labeled NSCs revealed the presence of numerous vesicles spreading in the cytoplasm and filled with electron-dense magnetic iron particles. The ferumoxides vesicles increased with the labeling concentration of ferumoxides, and at the final concentration exceeding 25 microg/ml, ferumoxides vesicles in the NSCs gave rise to conglomeration which hampered observation of the cellular ultrastructure by transmission electron microscope. The results of flow cytometry and MTT assay demonstrated that the cell viability, proliferation, differentiation and apoptosis of the labeled cells were affected by ferumoxides at the concentration above 25 microg/ml, but such effects could be minimal at lower concentrations.


CONCLUSIONS
Ferumoxides might be feasible for in vitro labeling of the NSCs with the optimal concentration of 25 microg/ml.
Dai
Guang-Hui
GH
Institute of Neuromedicine, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. daig74@126.com
Xiu
Jun-Gang
JG
Zhou
Zhen-Jun
ZJ
Chen
Zhong-Can
ZC
Xu
Ru-Xiang
RX
Jiang
Xiao-Dan
XD
Du
Mou-Xuan
MX
D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003911:Dextrans; D052203:Ferrosoferric Oxide; D007501:Iron / Q000494:pharmacology*; D058185:Magnetite Nanoparticles; D008297:Male; D046529:Microscopy, Electron, Transmission; D009474:Neurons / Q000166:cytology* / Q000648:ultrastructure; D010087:Oxides / Q000494:pharmacology*; D051381:Rats; D013234:Stem Cells / Q000166:cytology* / Q000648:ultrastructure
D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide