The Effects Of Megration Of Superparamagnetic Iron Oxide(SPIO)-labelled Mesenchymal Stem Cells By A Magnet On Brain Infarction In Rat Model

Objective With the development of cell biological technology, moreand more important functions and potential of stem cells have beendiscovered. The method of using stem cell transplants to repair damagedtissue has great potential. As one of noninvasive detection mean andadvanced cell therapy, superparamagnetic iron oxide(SPIO) has been usedto trace labeled cell in numerous research fields.The Using of SPIO in celldynamic for monitoring the transplantation process of stem cell has becomea reality. The labeled bone marrow mesenchymal stem cells(BMSCs)played an important role in the curing central nervous system diseases andimproving the function of nerve, of course, the research of this area has gotmany progresses and definite curative effects. as a result of iron, SPIO hassome side-effects to stem cell. if the iron excessive accumulated, it willpoison the cells, even make them death.In the high consistency of iron,theviability and proliferation activity of BMSCs were serious damaged,Theobjectives of this research project are (1)using the vitro test of the viability and proliferation activity of SPIO-labeled BMSCs,to evaluate the safety ofSPIO.(2) using the magnetic fields to make the SPIO-labeled BMSCsdirectionally migrate to the lesion part of the brain of animal models of rats.And recording the NSS score,and results of histological examination, ironcontent of brain, the area of Cerebral ischemia to analyse the function ofmagnetic fields and the curing effects of BMSCs.Methods This research used30clean SD rats. After cultivated in thevitro tests,the rat mesenchymal stem cells was labeled with SPIO in vitroand divided into two groups. and prussian blue staining was used to checkthe rate of SPIO. The viability and proliferation activity of labeled stemcells was evaluated by trypan blue staining. The cck-8assay was performedto detect the labeled stem cell proliferation activity in the magnetic field.The middle cerebral artery occlusion (MCAO) was established in a ratmodel by the method of Longa, and the neurological severity score (NSS)was used to evaluate neurological function recovery of rats at definite timefollowing the injection of transplanted cells. The transplanted BMSCs wereanalyzed in recipient rat brains by Prussian blue staining. The cerebralischemia area was observed via TTC staining. The iron content ofSPIO-labeled BMSCs was analyzed by atomic absorptionpectrophotometer.Results (1) vitro tests: Prussian blue staining showed that the rate ofBMSCs labeled superparamagnetic iron oxide was close to100％. Trypan blue staining and CCK-8assay indicated that there was no significantdifference among labeled group,control group and magnetic group（P>0.05）. The BMSCs of ICSM group within the brain was significantlymore than the BMSCs of ICS group (P <0.05) whthin the distance of0to12mm from the magnetic fields.but out of the distance,they have nosignificant difference（P>0.05）.(2) vivo tests: The ICSM group with ischemia seven days later showedbetter compared to the other two groups. The difference was significant(P<0.05). The brain iron content in the ICSM group was largely morethan that in the ICS group (P<0.05).Conclusion The method of SPIO is safe and will not lead to ironaccumulation. And it will not affect the the viability and proliferationactivity of BMSCs after they were labeled. External magnetic field cantarget delivery bone marrow mesenchymal stem cells labeled withsuperparamagnetic iron oxide in vitro and in vivo, and can obviouslyimprove the transplantation of SPIO-Labeled mesenchymal stem cells.