Passage of superparamagnetic iron oxide labeled rat bone marrow mesenchymal stem cells in vitro: Do iron particles change with passage? / 中国组织工程研究

ABSTRACT

BACKGROUND: As magnetic resonance (MR) contrast, a large number of clinical and experimental researches have been done on superparamagnetic iron oxide (SPIO), while the report on the labeled cell passaged cells is rare.OBJECTIVE: MR imaging was performed to the labeled bone mesenchymal stem cells (BMSCs) and its passaged cells in vitro, in order to establish the base of monitoring magnetic labeled BMSCs with magnetic resonance imaging (MRI) in vivo.DESIGN, TIME AND SETTING: The cytological in vitro experiment was performed at the Imaging Research Institute and Institute of Rheumatology and Immunology of North Sichuan Medical College Hospital from June 2006 to January 2007. MATERIALS Two clean female albino rats (Animal Center, North Sichuan Medical College), SPIO (Schering AG,Germany) were used in this study.METHODES Bilateral femur and tibia bone marrow was extracted from rats. BMSCs were harvested and purified using the adherent method, and then labeled with 600 μL ferric oxide-polylysine compound (42 mg/L iron concentration) in vitro. MAIN OUTCOME MEASURES: Cell maker-positive rate and the MR signal intensity were respectively measured to the labeled cells and its passaged cells under the inverted microscope and magnetic resonance imaging. RESULTS: Following Prussian blue staining, labeling rate of SPIO labeled cells at the first passage was 100%. With increased passage, the labeling rate was reduced from the first to fifth passages. Compared with non-labeled PBS control, there was no significant difference in signal intensity in the first and second passages cells, but the signal intensity percentage was gradually decreased with signal intensity of increased cell passage from the third passage. Cell labeling rate was negatively correlated with T2~*WI signal intensity (r=-0.986 6, P <0.005). CONCLUSION: The iron particles in the magnetic labeled cells can be passaged to the offspring cells, and can be monitored in a certain period of time with MRI in vitro. These results firstly introduced that SPIO-labeled cell iron particles can decrease with cell passage.