title: [Effect of superparamagnetic iron oxide labeling on neural stem cell survival and proliferation].
abstract: 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.
authors.affiliation: Institute of Neuromedicine, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. daig74@126.com
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Dai
authors.forename: Jun-Gang
authors.initials: JG
authors.lastname: Xiu
authors.forename: Zhen-Jun
authors.initials: ZJ
authors.lastname: Zhou
authors.forename: Zhong-Can
authors.initials: ZC
authors.lastname: Chen
authors.forename: Ru-Xiang
authors.initials: RX
authors.lastname: Xu
authors.forename: Xiao-Dan
authors.initials: XD
authors.lastname: Jiang
authors.forename: Mou-Xuan
authors.initials: MX
authors.lastname: Du
mesh_terms: 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
chemical_list: D003911:Dextrans; D058185:Magnetite Nanoparticles; D010087:Oxides; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide