| Objective:To investigate the therapeutic effects of intravenously injected superparamagnetic iron oxide nanoparticles(SPIONs)-labeled adipose-derived stem cells(ADSCs)on spinal cord injury(SCI)in rats.Methods:(1)ADSCs were extracted from the inguinal fat of 12-week-old SD rats,subcultured to the third generation.The surface antigens of ADSCs were identified by flow cytometry,ADSCs were labeled by SPIONs,and ADSCs were divided into magnetic label group and non-magnetic label group.The success rate of SPIONs was detected by Prussian blue staining.The survival rate and proliferation ability of labeled ADSCs were detected by trypan blue staining and CCK-8.(2)30 rats of 12-week-old SD rats were prepared into the rat SCI model by modified Allen's method.They were randomly divided into magnetic field group,non-magnetic field group and control group.The sample size of each group was 10,both magnetic field group and non-magnetic field group.On the 1st,2nd,and 3th day after transplantation of ADSCs,0.3ml of ADSCs suspension with a density of 1×10~7/ml SPIONs was injected.The magnetic field group also placed 300MT neodymium iron boron magnet in the spinal cord injury site,and the control group was injected with the same amount of DMEM High sugar medium.(3)In each group,the degree of spinal cord injury was scored by injury behavioral(BBB)method at 1w and 2w after transplantation of ADSCs.HE staining analysis was used to observe the morphology of injured spinal cord and the content of ADSCs labeled with Prussian blue staining in spinal cord injury.The expression of growth-associated protein-43(GAP-43)in spinal cord tissue was determined by Western blotting.Results:1.ADSCs were successfully isolated from rat adipose tissue,and the expression of CD44 and CD49 was 50.12%and 44.17%,and the expression of CD14and CD45 was 0.78%and 2.16%by flow cytometry.The blue staining detection SPIONs can 100%label ADSCs;the trypan blue staining method for the magnetic label group and the non-magnetic label group on the 1st,3d,7d survival percentage detection were(97.39±1.35)%,(96.61±0.71)%,(95.99±1.60)%,(96.52±1.31)%,(96.52±1.68)%,(97.13±1.89)%,no statistical difference(P>0.05);CCK-8 method for magnetic label group and non There was no difference in the proliferative capacity between the 1st,3rd,and 7th magnetic groups(P>0.05).2.The rat SCI model was successfully established.The postoperative BBB scores were 0 points.3.ADSCs transplantation On the 7th day,the BBB scores of the post-magnetic field group,the non-magnetic field group and the control group were 5.33±0.24,3.73±0.60,3.33±0.41,and the 14th day6.33±0.53,5.13±0.56,4.40±0.44,the magnetic field group at two time points.The scores were higher than those in the non-magnetic field group(P<0.05).The results of HE staining showed that the magnetic field group was smaller than the non-magnetic field group and the control group.More regular,cell vacuolization,inflammatory cell infiltration and scar formation;2w Prussian blue staining of spinal cord showed that the magnetic staining rate of magnetic field group was significantly higher than that of non-magnetic field group(P<0.05);magnetic field group was transplanted after ADSCs The expression of GAP-43 at 1w and 2w was significantly higher than that in non-magnetic field group and control group(P<0.05).Conclusion:The external magnetic field at the site of spinal cord injury has a guiding effect on SPIONs-labeled ADSCs,which can directional migration of ADSCs and improve the efficacy of stem cell targeted therapy for spinal cord injury. |
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