超顺磁性纳米铁粒子标记骨髓基质干细胞及对其分化能力的影响

Effect of superparamagnetic iron nanoparticle labeling on bone marrow stem cells'abilities to survive, proliferate and differentiate into hepatocytes

目的研究超顺磁性纳米铁粒子标记骨髓基质干细胞(BMSCs)对其存活、增殖及向肝细胞分化能力的影响,确定最佳标记浓度,为磁共振成像(MRI)技术追踪同种异体移植的磁标记细胞奠定基础。方法使用菲立磁(Ferumoxides)标记大鼠BMSCs,采用Prussianblue染色、电镜等鉴定Ferumoxides标记BMSCs的效率;检测标记后BMSCs的诱导分化率评估其向肝细胞分化能力。门静脉和肝内局部移植标记BMSCs后行MRI肝脏扫描。结果标记培养基Fe3+浓度在11.2￣16.8μg/mL时,Prussianblue染色可见90%以上细胞阳性,透射电镜可见铁颗粒位于胞浆中;标记后BMSCs向肝细胞分化的能力与正常未标记BMSCs差异无统计学意义(P>0.05);Fe3+浓度在5.6μg/mL时,着色率<60%;Fe3+浓度为22.4μg/mL、28.0μg/mL时培养基中死细胞增多,且诱导分化后AFP与白蛋白阳性率降低,与对照组比较差异有统计学意义(P<0.05)。标记BMSCs门静脉和肝内局部移植后大鼠肝脏在MRI的SE-T2WI序列扫描下与移植前比较局部呈明显低信号改变。结论标记培养基Fe3+浓度在11.2￣16.8μg/mL时,Ferumoxides对BMSCs标记效率较高,且不影响其存活、增殖及向肝细胞分化能力,标记后的BMSCs可用于进一步实验。活体MRI示踪肝内或门静脉移植Ferumoxides标记的BMSCs有一定的可行性。

Objective To study the effect of superparamagnetic iron nanoparticle labeling on bone marrow stem cells （BMSCs）＇ ability to survive, proliferate and differentiate into liver cells and to provide a possible way of Magnetic resonance imaging （MRI） to trace the implanted labeled cells in livers. Methods Ferumoxides was used to label BMSCs. Prussian blue staining, electronmieroscope were used to evaluate the labeling efficiency of Ferumoxides labeled BMSCs. The differentiation rate of BMSCs was detected to evaluate their ability to differentiate into liver cells after Ferumoxides labeling. MRI scan was conducted to test rat＇s livers after implanted with labeled BMSCs from portal vein and liver texture to livers. Results Above 90% of the cells was positively labeled and iron particles were found in their endochylema through the electron microscopy when ferri ion was at the concentration of 11.2-16.8 μg/mL in the medium. There was no significant difference between labeled cells and unlabeled cells in the abilities to differentiate to liver cells（P〉0.05 ）. Labeling rate was below 60% when ferri ion was under 5.8 μg/mL. Dead cells increased and differentiation ability decreased when ferri ion was 22.4 μg/mL or 28.0 μg/mL in the medium. MRI showed remarkable low-signal intensity changes in part of the rat livers transplanted with labeled BMSCs through portal vein or liver local injection. Conclusion The efficiency of labeling was high and Ferumoxides labeling did not affect the ability of BMSCs to survive, proliferate and differentiate to liver cells when ferri ion was at the concentration of 11.2-16.8 ug/mL in the medium. Ferumoxides can be used to label BMSCs in vitro and MRI plays a role in tracking of Ferumoxides-labeled BMSCs alter transplantation through portal vein or liver local injection in vivo.