论文部分内容阅读
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。
Objective To explore the feasibility of in vivo tracking of stem cells by using magnetic resonance imaging and the effect of stem cells on the volume of cerebral infarction in stroke rats. Methods The hindlimb femur and tibia bone marrow of rats were collected and bone marrow mesenchymal stem cells (BMSCs) were isolated and cultured by density gradient centrifugation. BMSCs were labeled with a mixture of superparamagnetic iron oxide and poly-L-lysine, and Prussian blue staining was used to detect the labeling rate. Eighteen rat models of cerebral ischemia and reperfusion were established by thread occlusion. The rats were divided into two groups: the contralateral BMSCs transplantation group (1.5 × 105 / 15μl), the ipsilateral striatum transplantation group (1.5 × 105/15 μl) and control group (15 μl D-Hanks solution), 6 mice in each group. MRI scans were performed on the first day after cerebral ischemia and on the first day and the fourteenth day after the cell transplantation respectively. The changes of the infarct volume at each time point were statistically analyzed. Results Superparamagnetic iron oxide labeled 96% of BMSCs. Magnetic resonance imaging showed that the BMSCs migrated to the periphery of the ischemic foci on the 14th day after transplantation, while the BMSCs on the contralateral ischemic side diffused along the corpus callosum. However, there was no significant difference in volume of cerebral infarction between the three groups (P > 0.05). Conclusion Superparamagnetic iron oxide has high labeling rate of stem cells, and magnetic resonance imaging is helpful to understand the survival and migration after stem cell transplantation. BMSCs intracerebral transplantation had no significant effect on the volume of cerebral infarction in stroke rats.