MRI示踪超顺磁性氧化铁标记骨髓间充质干细胞移植治疗股骨头缺血性坏死

背景：骨髓间充质干细胞移植是治疗股骨头坏死的发展方向之一。近年来，利用超顺磁性氧化铁纳米颗粒标记靶细胞再经MRI显像的方法已成为研究的焦点。目的：观察超顺磁性氧化铁标记的骨髓间充质干细胞在MRI信号上的变化情况及对兔股骨头坏死的修复效果。方法：将超顺磁性氧化铁标记的兔骨髓间充质干细胞、未标记的骨髓间充质干细胞、生理盐水采用原位移植方式移植入兔股骨头坏死区，行MRI检测，观察移植入坏死区的超顺磁性氧化铁标记的骨髓间充质干细胞在SE T2WI、FSE T2WI、GRE T2WI 三种扫描序列中信号变化情况；同时行组织学观察及高倍镜下缺损标本边缘新生骨小梁面积百分比行统计学分析。结果与结论：超顺磁性氧化铁标记的骨髓间充质干细胞原位移植侧，在SE T2WI、FSE T2WI、GRE T2＊WI 三种扫描序列中信号减低区即为实验中的靶点，MRI图像示靶点在3种扫描序列中信号强度均有不同程度的降低，而对照侧则无明显信号改变；移植后6周，超顺磁性氧化铁标记的骨髓间充质干细胞移植侧高倍镜下缺损标本边缘新生骨小梁面积百分比与未标记的骨髓间充质干细胞移植侧间差异无显著性意义（P〉0.05），均高于生理盐水移植侧，差异有显著性意义（P〈0.01）。结果可见超顺磁性氧化铁标记的骨髓间充质干细胞与未标记的骨髓间充质干细胞原位移植治疗兔股骨头坏死有着同样的效果，MRI 可对超顺磁性氧化铁标记的骨髓间充质干细胞进行活体示踪检测。

MRI tracking of superparamagnetic iron oxide-labeled rabbit bone marrow mesenchymal stem cells for treatment of femoral head avascular necrosis

BACKGROUND：Bone marrow mesenchymal stem cell（BMSC） transplantation is one of the developmental directions in the treatment of femoral head necrosis. In recent years, the use of superparamagnetic iron oxide （SPIO） nanoparticles labeled target cells traced by MRI imaging method has become the focus of the study. OBJECTIVE：To observe the in vivo MRI tracking and the curative effects of SPIO-labeled BMSC transplantation on rabbit femoral head necrosis.METHODS：SPIO-labeled BMSCs, unlabeled BMSCs, and normal saline were injected in situ into the necrotic femoral head of rabbits. Fol owing MRI dectection, the image changes of transplanted BMSCs marked by SPIO were observed among the three scanning sequences of SE T2WI, FSE T2WI and GRE T2＊WI. Meanwhile, the area percentage of newly formed bone trabecula in the defect samples under high power lens were observed and calculated for statistical analysis. 〈br〉 RESULTS AND CONCLUSION：In situ celltransplantation group showed the emerging and extinctive time of the decreased-signal region was different among the three scanning sequences of SE T2WI, FSE T2WI and GRE＆amp;nbsp;T2＊WI. It was found that the decreased-signal region of the MRI scanning sequences was the target of the present experiment. No obvious signal change occurred in the control side. After 6 weeks of transplantation, the area percentage of newly formed bone trabecula in the defect samples showed no difference in SPIO-labeled and unlabeled BMSC transplantation groups （P〉0.05）, but it was higher than that in the control side （P〈0.01）. The SPIO-labeled BMSCs and unlabeled BMSCs are shown to have the same effects in the treatment of femoral head necrosis. The SPIO-labeled BMSCs can be observed obviously by MRI detection in vitro.