The Effects Of Target Delivery Of Bone Marrow Mesenchymal Stem Cells By A Magnet On A Rat Model Of Spinal Cord Injury And The Expression Of Gap-43Preotein

Purpose: To investigate the effects of target delivery of magnet field onSPIO-labeled BMSCs in vitro and observe whether the magnet field couldpromote labeled cells targeted migration and reduce the damage area of SCIin vivo.Methods:①BMSCs from Sprague Dawley(SD) Rats were culturedin vitro with whole bone marrow culture. The expression of CD29、CD45、CD54was checked by Flow cytometric detection.②The BMSCs werelabeled with SPIO and prussian blue staining was performed to check thesuccess rate of SPIO labling.③The viability of labeled cells was evaluatedby trypan blue staining. CCK-8method was used to detect the proliferationof labeled cells with the presence magnetic field.④Rats were induced byClip Compression Method to establish the spinal cord injury models. TheBMSCs labeled with SPIO were injected though tail vein.⑤Neurologicalfunctions were evaluated by using Basso-Beattie-Bresnehan LocomotorRating Score3d,7d after cells transplantation. The transplantedlabeled-cells in recipient rat spinal cord were analyzed by prussian bluestaining.⑥The spinal cord ischemia area was checked by TTC Staining. The detection of GAP-43protein expression of spinal cord with SCI aftercell transplantation was investigated by Western Blot.Results:①In vitro, the stable BMSCs could be successfully obtainedthrough separation, culture and passage.The Flow cytometric test showedthat BMSCs do not express the hematopoietic stem cells marker CD45butexpress the mesenchymal stem cells markers CD29and CD54.②ThePrussian Blue Staining showed that the percentage of BMSCs labeled withsuperparamagnetic iron oxides was close to100%.③Trypan blue stainingshowed that there was no significant difference on the viability betweenlabeled group and control group. CCK-8test didn’t showed any significantdifference on proliferation between magnetic group and control group.④The BBB score of magnetic group was better than the control group.Prussian Blue Staining of spinal cord slices showed a higher number ofPrussian blue-positive BMSCs in the group with both SCI and the presenceof magnetic field than that in the SCI group without magnet.⑤TTC dyeingshowed the average ischemia size in spinal cord with magnet wassignificantly smaller than that in control group. The Western Blot showedthere was a significant higher expression of GAP-43protein in the groupwith magnetic field as compared to the other two groups at day3and day7after cell transplantation.Conclusion:①SPIO could successfully label the BMSCs and there’sno negative effects on the viability and proliferation②External magnetic field could target delivery more BMSCs labeled with superparamagneticiron oxides to the scathing area in vivo which could ease the spinal cordinjury and could increase the expression of GAP-43protein in spinal cordinjury, which is good for the recovery of spinal cord injury...