体外纳米磁标记骨髓间充质干细胞生物学特性及其MR成像  

Biological characteristics and in vitro MRI of superparamagnetic iron-oxide labeled bone-derived mesenchymal stem cells from rabbits

作　　者：金旭红[1] 杨柳[1] 段小军[1] 陈伟[2] 李忠[1] 

机构地区：[1]第三军医大学西南医院关节外科中心,重庆400038 [2]第三军医大学西南医院放射科,重庆400038

出　　处：《第三军医大学学报》2008年第4期275-279,共5页Journal of Third Military Medical University

基　　金：国家自然科学基金(30300079,30670527);全军医学科研“十一五”计划科技攻关项目(06G079)~~

摘　　要：目的研究超顺磁性氧化铁粒子(superparamagnetic iron oxide particles,SPIO)体外标记兔骨髓间充质干细胞(mesenchymal stem cells,MSCs)及MR细胞成像示踪可行性。方法从兔骨髓中分离培养MSCs,体外不同浓度SPIO联合硫酸鱼精蛋白标记,未标记细胞设为对照组。普鲁士蓝染色和电镜检查鉴定细胞内铁颗粒,台盼蓝染色检测细胞存活,MTT法测定细胞生长曲线的变化,磁标记MSCs转入成骨、成脂肪培养基中进行诱导培养后进行鉴定,应用1.5TMR梯度回波T2加权(GRET2*WI)扫描序列和自旋回波T2加权(SET2WI)扫描序列对磁标记细胞成像示踪。结果普鲁士蓝染色和电镜检查显示细胞质内含致密铁颗粒,磁标记对MSCs活性和增殖无统计学差异(P>0·05),标记细胞可正常成骨、成脂肪分化。GRET2*WI序列和SET2WI序列提示与未标记细胞信号强度(SI)相比,1×106(标记细胞)、5×105(标记细胞)SI均显著性下降(P<0·05),其中GRET2*WI的信号强度衰减率(△SI)显著高于T2WI序列(P<0·05)。在2个序列中1×106(标记细胞)△SI均高于5×105(标记细胞)△SI,但不具有显著性差异(P>0·05)。结论SPIO联合硫酸鱼精蛋白转染剂能成功标记MSCs,磁标记对细胞存活、增殖及潜在多向分化能力无影响。磁标记细胞在MR上产生特征性的低信号改变。应用1.5TMR成像示踪标记细胞可行,以GRET2*WI序列成像最为敏感。Objective To label rabbit bone marrow-derived mesenchymal stem cells （MSCs） with superparamagnetic iron oxide particles （SPIO） and study the effects of magnetic labeling on the proliferation and differentiation of MSCs. Methods Rabbit MSCs were isolated, purified, expanded, then incubated with various doses of SPIO complexed to protamine sulfate （Pro） transfection agents for 12 h. Prussian blue staining and transmission electron microscopy were performed to show intracellular iron. Cell viability and differentiation were evaluated. Vials containing cells underwent 1.5T MR imaging （MRI） with GRE T2^＊WI weighted and SE T2WI sequence, and the signal intensity were measured and statistically analyzed. Results Intracytoplasmic nanoparticles were confirmed by Prussian blue staining and transmission electron microscopy. As compared with the unlabeled cells, no significant difference was found in cell viability, growth rate and differentiation of the labeled MSCs. GRE T2^＊ WI and T2^＊WI demonstrated significant decrease of signal intensity （SI） in vials containing 1 ×10^6 and 5 ×10^5 labeled cells, in comparison with unlabeled cells （P 〈0. 05）. The percentage change of SI （△SI） was significantly higher in 1×10^6 labeled cells than that in 5×10^5 labeled cells, particularly on GRE T2^＊WI （P 〈 0. 05 ）. Among pulse sequences, GRE T2 demonstrated the highest △ SI ut significant （P 〈 0. 05 ）. Conclusion MSCs can be labeled with Fe-Pro efficiently witho change in cell viability and differentiation capacity. Visualization of SPIO-labeled MSCs by 1.5T MRI is feasible.

关 键 词：超顺磁性氧化铁粒子 骨髓间充质干细胞 磁标记细胞 磁共振成像 

分 类 号：R329.1[医药卫生—人体解剖和组织胚胎学] R445.2[医药卫生—基础医学]