超顺磁性氧化铁标记骨髓间充质干细胞心肌活体示踪及体外实验

In vivo and in vitro tracking of bone marrow mesenchymal stem cells delivered to infarcted myocardium by superparamagnetic iron oxide nanoparticles

背景:活体示踪移植干细胞,影像学评估移植细胞动态变化的趋势是目前的热点研究方向。目的:探讨MRI活体示踪超顺磁性氧化铁标记的骨髓间充质干细胞移植修复心肌的可行性及有效性。方法:经导管应用球囊封堵前降支动脉建立家猪心肌梗死模型,造模成功的动物随机分为2组:实验组在造模2周后于梗死区中央及梗死边缘区共5个点注射超顺磁性氧化铁-多聚赖氨酸混合物标记的骨髓间充质干细胞悬液1mL,对照组以同样方法注入等量的生理盐水。结果与结论:细胞移植后1h,2周,实验组中4只动物(100%)移植区在磁共振上呈明显的低信号改变,移植后4周示3只动物(75%)细胞移植区有低信号改变。移植后4周,心肌组织荧光免疫组化检测心脏结蛋白、心脏连接蛋白和心肌早期转录蛋白均有表达。结果可见应用MRI技术活体示踪动态观察移植的骨髓间充质干细胞是可行有效的。

BACKGROUND：In vivo tracking of transplanted stem cells and evaluating the dynamic changes of transplanted stem cells by imageological means is currently a rapidly growing area of research. OBJECTIVE：To investigate the feasibility of in vivo and in vitro tracking of mesenchymal stem cells delivered to infarcted myocardium by surpurparamagnetic iron oxide nanoparticles. METHODS：Eight pig models of acute myocardial infarction were successfully established by occlusion of anterior descending coronary artery with balloon and were then randomly divided into two groups. In the experimental group, at 2 weeks after acute myocardial infarction induction, 1 mL bone marrow mesenchymal stem cells labeled by the mixture of surpurparamagnetic iron oxide nanoparticles and polylysine were injected via five points in the center and border of infracted region. Equal amounts of physiological saline were identically injected in the control group. RESULTS AND CONCLUSION：At 1 hour, 2 weeks after cell transplantation, MRI images of experiment group showed obvious low signal of transplantation region in all four pigs. At 4 weeks after transplantation, desmin, connexin and transcription protein were detected by fluorescent immunohistochemical staining. In vivo tracking of surpurparamagnetic iron oxide nanoparticles-labeled bone marrow mesenchymal stem cells by MRI is feasible and effective.