MRI活体示踪大鼠脑内超顺磁性氧化铁标记成人神经干细胞

背景：目前判断神经干细胞移植后向脑损伤部位的迁移需要处死受体动物行脑切片检查，且不能进行多点、动态的观察。 目的：探讨用MRI活体示踪移植磁化标记成人神经干细胞在创伤性脑损伤模型大鼠脑内迁移和分布的可行性。 方法：建立大鼠脑部左侧半球创伤性脑损伤模型，超顺磁性氧化铁体外标记成人神经干细胞。模型建立后2周将标记成人神经干细胞立体定向移植入大鼠脑部右侧半球。在移植后1 d、3 d、1周和2周分别行大鼠头部MRI。2周后处死大鼠取脑，用普鲁士蓝染色法进行染色，观察标记神经干细胞的迁移。 结果与结论：超顺磁性氧化铁体外标记成人神经干细胞的成功率约为85%。移植后行头颅MRI可见位于右侧半球的移植部位FSE T2WI和GRE T2序列呈环形低信号。随时间推移，创伤性脑损伤后移植标记干细胞组大鼠头颅MRI可见脑内有一低信号线，指向对侧脑挫伤部位，而创伤性脑损伤后移植未标记干细胞组，正常大鼠移植标记干细胞组无信号线。MRI显像结果与脑切片普鲁士蓝染色观察到的结果是相符合的。 结果提示用MRI活体示踪移植磁化标记成人神经干细胞在创伤性脑损伤模型大鼠脑内迁移和分布可行、有效。

In vivo magnetic resonance imaging tracking of transplanted Feridex-labeled adult neural stem cells in rats

BACKGROUND: At present, brain section examination was needed to judge whether neural stem cells (NSCs) migrated towards damaged region following transplantation by sacrificing recipient animals, and multiple points and dynamic observation cannot be performed. OBJECTIVE: To study the feasibility of magnetic resonance imaging (MRI) tracking of transplanted Feridex-labeled adult NSCs in vivo in rats with traumatic brain injury model. METHODS: Traumatic brain injury model was established in the left hemisphere of the rats. In vitro adult NSCs were labeled by Feridex. 2 weeks later, Feridex-labeled adult NSCs were implanted into the right hemisphere. All rats received MRI at 1, 3 days, 1 and 2 weeks after implantation. 2 weeks after implantation, all the rats were killed and their brains were taken out to undergo Prussian blue staining to track the presence of labeled-cells. RESULTS AND CONCLUSION: Efficiency of labeled adult NSCs was about 85%. At implanted sites, low signal intensity could be observed in MRI examination with the scanning sequences of FSE T2WI and GRE T2. Low signal intensity lines were visible targeted to the contralateral lesion areas in labeled stem cell group. However, no signal line was found in the control group. The results from MRI were in accordance with the results from section with Prussian blue staining. These results indicated that MRI in vivo monitoring transplanted Feridex-labeled adult NSCs is feasible and effective in rats with traumatic brain injury model.