[Application of superparamagnetic iron oxide labeled antisense oligodeoxynucleotide probe in cellular magnetic resonance imaging].
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.
Wen
Ming
M
Department of Radiology, the First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
Li
Bi-Bo
BB
Ouyang
Yu
Y
Jiang
Ming-Dong
MD
Luo
Yi
Y
Li
Shao-Lin
SL
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
D016373:DNA, Antisense; D005290:Ferric Compounds; D009838:Oligodeoxyribonucleotides; D018719:Erb-b2 Receptor Tyrosine Kinases; C000499:ferric oxide