【摘要】 目的探索利用磁共振技术活体追踪干细胞的可行性以及干细胞对卒中大鼠脑梗死体积的影响。方法采集大鼠后肢股骨和胫骨骨髓,采用密度梯度离心法分离并培养骨髓间充质干细胞(BMSCs)。利用超顺磁性氧化铁和多聚左旋赖氨酸的混合物标记BMSCs,普鲁士蓝染色检测标记率。线栓法建立18只大鼠脑缺血2h再灌注动物模型,分为缺血对侧BMSCs移植组(细胞数1.5×105/15μl)、缺血同侧纹状体移植组(细胞数1.5×105/15μl)和对照组(15μlD-Hanks液)3组,每组6只。分别在脑缺血后第1天、细胞移植后第1天及第14天进行磁共振扫描,对各时间点梗死体积的变化进行统计学分析。结果超顺磁性氧化铁对BMSCs的标记率为96%。磁共振追踪显示移植后第14天缺血同侧移植组BMSCs向缺血灶边缘迁移,缺血对侧移植组BMSCs沿胼胝体弥散,但是3组之间的脑梗死体积变化差异无显著性(P>0.05)。结论超顺磁性氧化铁对干细胞标记率高,磁共振活体追踪有利于了解干细胞移植后的存活和迁移。BMSCs脑内移植对于卒中大鼠脑梗死体积的影响无统计学意义。更多还原

【Abstract】 Objective To explore the feasibility of in vivo tracking of bone marrow mesenchymal stem cells (BMSCs) labeled with superparamagnetic iron oxide(SPIO) by magnetic resonance imaging (MRI) in rats after cerebral ischemia, and to analyze the influence of stem cell therapy on the volume of cerebral infarction. Methods The samples of rat bone marrow were collected. BMSCs separated by density gradient centrifugation were cultivated and harvested until the third passage. BMSCs were labeled with SPIO, which was mixed with poly-L-lysine. The labeling efficiency was evaluated by Prussian blue staining. Transient middle cerebral arterial occlusion (MCAO) was performed successfully in 18 adult Sprague-Dawley rats that scored from 6 to 12 by the modified neurological severity test. The 18 rats were then randomly divided into group A, B, and C, with 6 rats in each group and Group C was regarded as control group. BMSCs were injected into the contralateral cortex of is chemia in group A, ipsilateral corpora striata in group B, while D-Hank’s solution was injected into ipsilateral corpora striata (group C) 24 hours after MCAO. MRI was performed 1 day after MCAO, 1 day and 14 days after transplantation. The volume of infarcted brain tissue was measured and analyzed. Prussian blue staining of brain tissues was performed to identify the migration of BMSCs. Results The labeling efficiency of BMSCs with SPIO was 96%. The transplanted BMSCs migrated to the ischemic hemisphere along the corpus callosum and to the border of the infarction, which was confirmed by MRI and Prussian blue staining. The changes of infarction volume were not significantly different among these three groups. Conclusions MRI is feasible for in vivo tracking of BMSCs labeled with SPIO in rats. The stem cell therapy may not be able to affect the volume of cerebral infarction.更多还原