7.0 T MRI体外标记Gd-DTPA对骨髓间充质干细胞的实验研究

Study of Gd-DTPA labeled bone marrow mesenchymal stem cells in vitro with 7.0 T MRI

目的研究MRI对比剂钆-二乙烯三胺五乙酸(Gd-DTPA)标记骨髓间充质干细胞(BMSC5)的可行性及标记之后体外MR成像示踪的可能性。材料与方法骨髓间充质干细胞由SD大鼠双侧股骨骨髓中获取,培养、传代并纯化细胞,采用临床通用Gd-DTPA增强剂标记骨髓间充质干细胞;透射电子显微镜观察标记情况,并用台盼蓝染色方法及噻唑蓝(MTT)法测定标记细胞的活力及增殖能力;对标记的细胞进行体外7.0 T MR成像。结果透射电子显微镜可清晰观察到Gd-DTPA颗粒大部分存在于骨髓间充质干细胞细胞浆中,少许贴附于细胞膜上。台盼蓝染色方法证实标记之后细胞的存活率没有受到影响,MTT法证实标记之后对BMSCs增殖能力没有影响。体外试管扫描示标记细胞呈高T1WI信号强度,并且持续时间较久。结论 Gd-DTPA标记细胞之后,BMSCs的活性及增殖能力没有受到影响,并且透射电镜结果证实Gd-DTPA颗粒存在于细胞胞浆内,在细胞胞膜上也有Gd-DTPA颗粒存在。标记的BMSCs在体外检测到明显的MRI信号强度改变。Gd-DTPA可以作为一种示踪剂用来MRI示踪研究。

Objective： The aim of this study was to explore the possibility of the rat bone mesenchymal stem cells （BMSCs） labeled with standard contrast agents （Gd- DTPA） for stem cell tracking. Materials and Methods： BMSCs from bilateral femur of rats were cultured and propagated. The BMSCs uptaked Gd-DTPA. Electron microscopy was performed to detect the distribution of Gd-DTPA particles in BMSCs. Viability and proliferation of labeled BMSCs were evaluated using trypan blue exclusion assays and MTT assay. Labeled BMSCs were detected with Tl-weighed MR imaging in vitro. Results： The presence of Gd-DTPA particles inside the BMSCs was definitely detected by transmission electron microscopy. There was no difference in viability and proliferation between the labeled and unlabeled cells. The labeled BMSCs demonstrated the high signal intensity on Tl-weighted MRI in vitro. Conclusion： Gd- DTPA shows no evident adverse effect on the function of labeled BMSCs. Gd-DTPA can be used for the MR imaging tracking of labeled BMSCs.