title: [Magnetic/luminescent quantum dots bifunctional nanoparticles labeling of rat bone mesenchymal stem cells].
abstract: OBJECTIVE
  To evaluate the dual-labeling efficiency of magnetic and luminescent quantum dots bifunctional nanoparticles to rat bone mesenchymal stem cells (BMSC).
  
  
  METHODS
  Rat BMSC were isolated, purified, and expanded. Magnetic/luminescent bifunctional nanoparticles (Fe(3)O(4)@CdTe@SiO(2)), were prepared by using silicon dioxide (SiO(2)) to encapsulate simultaneously Fe(3)O(4) and CdTe quantum dots. BMSC were incubated with the Fe(3)O(4)@CdTe@SiO(2) nanoparticles which iron concentration was 25 microg/ml. Fluorescence microscope was used to detect the fluorescence of the intracellular nanoparticles. The dual-labeled BMSC with various concentration underwent ex vivo MR imaging with T(1)WI, T(2)WI and T(2)(*)WI sequences. To show the intracellular iron of labeled cells, prussian blue stain was performed. Spectrophotometer was used to detect the iron concentration in the cells.
  
  
  RESULTS
  Intracellular red fluorescence of Fe(3)O(4)@CdTe@SiO(2) can be observed via fluorescent microscopy. Rat BMSC could be effectively dual-labeled with approximately 90% efficiency. The MR images with T(2)WI and T(2)(*)WI sequences, especially with T(2)(*)WI sequence, showed that the signals of the dual-labeled BMSC were lower than those of the unlabeled cells. Cellular total iron is 14.05 + or - 4.15 pg per cell. Iron containing intracytoplasmic vesicles could be observed with Prussian blue staining.
  
  
  CONCLUSIONS
  Rat BMSC can be dual-labeled successfully with Fe(3)O(4)@CdTe@SiO(2) magnetic/luminescent bifunctional nanoparticles successfully, and might serve as a tool for magnetic resonance imaging and in vivo optical imaging.
authors.affiliation: Laboratory of Molecular Imaging, Department of Radiology, the Third Affiliated Hospital, Sun Yet-Sen University, Guangzhou 510630, China.
authors.forename: Rong-hua
authors.initials: RH
authors.lastname: Yan
authors.forename: Hong
authors.initials: H
authors.lastname: Shan
authors.forename: Li-bo
authors.initials: LB
authors.lastname: Nie
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Kang-shun
authors.initials: KS
authors.lastname: Zhu
authors.forename: Hong-fei
authors.initials: HF
authors.lastname: Wang
authors.forename: Dong
authors.initials: D
authors.lastname: Ma
authors.forename: Li-ming
authors.initials: LM
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003287:Contrast Media; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D059630:Mesenchymal Stem Cells; D045663:Quantum Dots; D016719:Radioimmunodetection; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D003287:Contrast Media