title: [Application of superparamagnetic iron oxide labeled antisense oligodeoxynucleotide probe in cellular magnetic resonance imaging].
abstract: OBJECTIVE
  To prepare the superparamagnetic iron oxide (SPIO)-labeled antisense oligodeoxynucleotide (ASODN) probe and evaluate the application of this probe in cellular magnetic resonance imaging (MRI).
  
  
  METHODS
  We prepared the SPIO-labeled ASODN probe using chemical cross linking method to conjugate SPIO to ASODN, detected its configuration by atomic force microscopy, determined the conjugating rate and biology activation by high performance liquid chromatography, and detected the stability by polyacrylamide gel electrophoresis. After that, we transfected the SK-Br3 oncocytes which had over-expression of the c-erbB2 oncogene by this probes, observed the intracellular iron distribution by optical microscope, measured iron content by atomic absorption spectroscopy, and observed the signal change by MRI.
  
  
  RESULTS
  Atomic force microscope showed that the SPIO-labeled ASODN probe was mostly spherical and well-distributed, with a diameter of 25-40 nm and a conjugating rate of 100%. This probe had inhered biological activity and stability. In addition, light microscopy revealed an intracellular uptake of iron oxides in the transfected SK-Br3 oncocyte, and the iron content of the group of transfected SK-Br3 oncocytes was significantly higher than those of other contrast groups (all P < 0.01). MRI showed that transfected SK-Br3 oncocyte had the lowest signal among all other cells (all P < 0.05).
  
  
  CONCLUSIONS
  We prepared the SPIO-labeled ASODN probe successfully. It can effectively transfect SK-Br3 oncocyte and enter SK-Br3 oncocyte, and thus reduce the signal intension in MRI.
authors.affiliation: Department of Radiology, the First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Wen
authors.forename: Bi-Bo
authors.initials: BB
authors.lastname: Li
authors.forename: Yu
authors.initials: Y
authors.lastname: Ouyang
authors.forename: Ming-Dong
authors.initials: MD
authors.lastname: Jiang
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
authors.forename: Shao-Lin
authors.initials: SL
authors.lastname: Li
mesh_terms: D045744:Cell Line, Tumor; D016373:DNA, Antisense / Q000737:chemistry* / Q000235:genetics; D005290:Ferric Compounds / Q000737:chemistry*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D015336:Molecular Probe Techniques; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000235:genetics; D024862:Oxyphil Cells / Q000737:chemistry; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000235:genetics
chemical_list: D016373:DNA, Antisense; D005290:Ferric Compounds; D009838:Oligodeoxyribonucleotides; D018719:Erb-b2 Receptor Tyrosine Kinases; C000499:ferric oxide