小鼠胚胎干细胞磁标记并磁共振成像的研究  

MR imaging of embryonic stem cells labeled by superparamagnetic iron oxide

作　　者：王蓓[1] Marisa JACONI 黎健[3] 王雁[1] Jean-Paul VALLE 

机构地区：[1]卫生部北京医院急诊科,北京100730 [2]日内瓦大学附属医院 [3]老年医学研究所

出　　处：《中华医学杂志》2007年第23期1646-1648,共3页National Medical Journal of China

摘　　要：目的应用超顺磁氧化铁(SPIO)标记小鼠胚胎干细胞(ESC),并行磁共振成像,为心肌细胞移植体内示踪作初步准备。方法小鼠 ESC 及其分化的心肌细胞与 SPIO 孵育后行电镜分析、细胞内铁含量测定、[Ca^(2+)]共聚焦测定和 MR 成像。结果铁颗粒分布在胞质吞饮小泡内;使用转染技术的铁摄取高于未使用组;T_2WI 和 T_2~*WI 扫描序列均见标记细胞呈信号下降,程度随标记浓度的增加而增强;T_2~*WI 图像信号强度变化更大。标记心肌细胞在T_2~*WI 序列也呈显著的低信号改变。结论 SPIO 可有效标记 ESC 及其分化的心肌细胞,对细胞活性和分化能力无明显影响。常规1.5TMR 仪可进行标记细胞成像。Objective To evaluate the labeling efficiency of superparamagnetic iron oxide （SPIO） nanoparticles and its toxicity to mouse embryonic stem cells （ESCs） and （embryoid body （ES）-derived cardiomyoeytes. Methods Mouse ESCs of the line CGR8 were cultured and induced to differentiate into ES- derived cardiomyoeytes. The EB-derived cardiomyoeytes were coincubated with SPIO contrast agent at different concentrations （ 1, 8, 9. 3, 14, 28, and 56 mg/L） and transfection agent for 24 and 48 hours for cell labeling. Cells not labeled by SPIO and cells labeled by SPIO without transfection agent were used as controls. Spectrophotometer was used to detect the iron concentration in the cells. Confoeal microscopy was used to test the intracellular calcium levels （ [ Ca2^＋ ] i）. The ultrastructure of the cells was observed by electron microscopy. Ex vivo MRI was used to observe the signals of the cells. Results Iron-containing intracytoplasmic vesicles could be observed clearly with electron microscopy. The intracellular iron concentration was higher in the cells treated with transfection agent than in the cells not treated with transfection agent. The iron concentration of the cells treated with the SPIO at the concentration of 9. 3 μg/ml for 24 hours was the highest. There were no differences in the morphology, contractile areas （X^2 = 1.32 ;P = 0. 25 ）, and the beating frequency （ t = 1.73 ; P = 0. 10 ） between the EBs from iron-labeled ESCs and from the control ESCs. The rhythmic intracellular free Ca^＋2 fluctuation in the labeled cardiomyoeytes was similar to that of the controls. The MR images with T2WI and T2^＊ WI sequences, especially those with T2^＊ WI sequence, of the ESCs showed that the signals of the SPIO labeled cells were lower than those of the SPIO-labeled cells. Conclusion SPIO labeling of ESCs and ES-derived cardiomyoeytes does not influence the cell viability and proliferation. The standard 1.5T MR equipment can image the labeled cells, thus offering the possibility of cel

关 键 词：干细胞 磁共振成像 超顺磁氧化铁 

分 类 号：R445.2[医药卫生—影像医学与核医学]