title: Labeling efficacy of superparamagnetic iron oxide nanoparticles to human neural stem cells: comparison of ferumoxides, monocrystalline iron oxide, cross-linked iron oxide (CLIO)-NH2 and tat-CLIO.
abstract: OBJECTIVE
  We wanted to compare the human neural stem cell (hNSC) labeling efficacy of different superparamagnetic iron oxide nanoparticles (SPIONs), namely, ferumoxides, monocrystalline iron oxide (MION), cross-linked iron oxide (CLIO)-NH(2) and tat-CLIO.
  
  
  METHODS
  The hNSCs (5 x 10(5) HB1F3 cells/ml) were incubated for 24 hr in cell culture media that contained 25 microg/ml of ferumoxides, MION or CLIO-NH(2), and with or without poly-L-lysine (PLL) and tat-CLIO. The cellular iron uptake was analyzed qualitatively with using a light microscope and this was quantified via atomic absorption spectrophotometry. The visibility of the labeled cells was assessed with MR imaging.
  
  
  RESULTS
  The incorporation of SPIONs into the hNSCs did not affect the cellular proliferations and viabilities. The hNSCs labeled with tat-CLIO showed the longest retention, up to 72 hr, and they contained 2.15+/-0.3 pg iron/cell, which are 59 fold, 430 fold and six fold more incorporated iron than that of the hNSCs labeled with ferumoxides, MION or CLIO-NH(2), respectively. However, when PLL was added, the incorporation of ferumoxides, MION or CLIO-NH(2) into the hNSCs was comparable to that of tat-CLIO.
  
  
  CONCLUSIONS
  For MR imaging, hNSCs can be efficiently labeled with tat-CLIO alone or with a combination of ferumoxides, MION, CLIO-NH(2) and the transfection agent PLL.
authors.affiliation: Department of Neurology, Clinical Research Institute, Seoul National University Hospital, Seoul National University, Seoul, Korea.
authors.forename: Miyeoun
authors.initials: M
authors.lastname: Song
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Moon
authors.forename: Yunhee
authors.initials: Y
authors.lastname: Kim
authors.forename: Dongyeol
authors.initials: D
authors.lastname: Lim
authors.forename: In-Chan
authors.initials: IC
authors.lastname: Song
authors.forename: Byung-Woo
authors.initials: BW
authors.lastname: Yoon
mesh_terms: D002478:Cells, Cultured; D003287:Contrast Media / Q000138:chemical synthesis / Q000493:pharmacokinetics; D003432:Cross-Linking Reagents / Q000737:chemistry; D003911:Dextrans; D005290:Ferric Compounds / Q000737:chemistry / Q000493:pharmacokinetics*; D052203:Ferrosoferric Oxide / Q000138:chemical synthesis / Q000493:pharmacokinetics; D015696:Gene Products, tat / Q000737:chemistry; D006801:Humans; D007501:Iron / Q000493:pharmacokinetics*; D008279:Magnetic Resonance Imaging / Q000379:methods; D058185:Magnetite Nanoparticles; D053758:Nanoparticles; D054259:Neural Tube; D010087:Oxides / Q000493:pharmacokinetics*; D019047:Phantoms, Imaging; D011107:Polylysine / Q000493:pharmacokinetics; D013054:Spectrophotometry, Atomic; D013194:Staining and Labeling / Q000379:methods*; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
chemical_list: D003287:Contrast Media; D003432:Cross-Linking Reagents; D003911:Dextrans; D005290:Ferric Compounds; D015696:Gene Products, tat; D058185:Magnetite Nanoparticles; D010087:Oxides; C499827:monocrystalline iron oxide nanoparticle; C000499:ferric oxide; D011107:Polylysine; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide