菲立磁标记兔BMSCs自体移植脊髓后的核磁共振活体示踪及形态学研究

Tracing and morphology of rabbit bone marrow-derived neural stem cells labeled with Ferumoxides after autografted into spinal cord

目的通过观察菲立磁标记兔骨髓源性神经干细胞(BMSCs)自体移植脊髓后的核磁共振活体示踪及形态,期待找到一种应用非侵袭性方法来识别、跟踪BMSCs的存活状态及与宿主组织整合情况的方法。方法无菌条件下股骨取骨髓,梯度密度离心法分离获取兔骨髓基质细胞;使用“Feridex-多聚赖氨酸复合物(FE-PLL)”标记骨髓基质细胞,采用普鲁士兰染色和台盼蓝排除实验等方法鉴定FE-PLL标记兔骨髓基质细胞的效率和细胞的活力;体外标记的细胞自体脊髓移植,磁共振、免疫组织化学染色和透射电镜检查。结果普鲁士蓝染色显示FE-PLL标记骨髓基质细胞胞质内出现细小的蓝色铁颗粒;与正常未标记的细胞相比较,FE-PLL标记对骨髓基质细胞的活力、增殖和分化等能力没有明显的影响;经菲立磁标记的兔BMSCs自体脊髓移植后,可在核磁共振上活体示踪。结论菲立磁与核磁共振联合可无创性活体标记检测移植的神经干细胞基本的存在部位、存在方式及其一些生物学特性,可以用来活体示踪移植的BMSCs。

Objective To explore the identification and tracing at magnetic resonance imaging （MRI） of Ferumoxides-labeled neural stem cells derived from rabbit bone marrow after autografted into spinal cord. Methods Under the sterile condition, the rabbit bone marrow stromal cells （BMSCs） were isolated by means of density gradient centrifugation following a thighbone puncture. Feridex-poly-l-lysine （FE-PLL） complexes were used to magnetically label BMSCs. The FE-PLL labeling rate and the vitality of labeled cells were examined by prussian blue staining and trypan blue exclusion test. The Ferumoxideslabeled neural stem cells derived from rabbit bone marrow after autografting of spinal cord were observed by electron microscopy and MRI. Results Prussian blue staining of FE-PLL labeled BMSCs revealed the presence of electron-dense iron particles in the cytoplasm. Compared with the unlabeled normal BMSCs, the labeled cells had no significant difference in the vitality, proliferation and differentiation. What＇s more, the FE-PLL labeled BMSCs could be traced at MRI after auto-grafted into spinal cord. Conclusion Feridex might be used to label neural stem cells derived from rabbit bone marrow and then MRI to detect the position, state and some biological features of the cells after auto-grafted into spinal cord.