新型超顺磁性氧化铁在干细胞活体示踪中的应用研究

目的：研究超顺磁性氧化铁（superparamagnetic iron oxide，SP10）标记干细胞的效率及其在磁共振活体示踪中的应用价值。方法：以3-氨丙基三乙氧基硅烷（APTS）修饰Fe2O3配制成SP10，用SP10转染标记骨髓间充质干细胞（MSCs），对标记后的MSCs行普鲁士蓝染色鉴定、MTT测试细胞相对数量。最后将标记后的MSCs移植入大鼠脑内，磁共振（MRI）扫描示踪显示。结果：普鲁士蓝染色可直接显示SP10高效率标记MSCs，MTT测试表明SP10标记对MSCs增殖数量及其活力无明显影响，MRI检查发现脑内移植的SP10标记MSCs在T2上呈明显的低信号。结论：APTS修饰Fe2O3配制而成的新型SP10对细胞无明显毒性，没有多聚赖氨酸（PLL）等转染剂仍可直接高效率标记MSCs，MRI活体显影示踪效果良好。

Application research of superparamagnetic iron oxide in vivo tracing of stem cells

AIM： To investigate a new superparamagnetic iron oxide（SPIO） which could label stem cells efficiently and be traced in vivo by magnetic resonance without poly-L-lysine or other transfection agent. METHODS： SPIO nanoparticles was prepared with Fe203 coated by a thin layer of 3-aminopropyltriethoxysilane, and then the compound （SPIO） was used to labeled Marrow Mesenchymal Stem Cells （MSCs）. The labeled MSCs were identificated by prussian blue stain and counted by MTT. Atlast, labeled MSCs was transplanted into rat brain and scanned by MRI. RESULTS： Prussian blue stain indicated that MSCs could be high efficiently labeled by SPIO, and there was no significant effect on the proliferation and viability of labeled MSCs by MTT. Hypo-intense changes of MRI T2 examination could be observed in the transplanted area of MSCs labeled by SPIO after transplantation in rats brain. CONCLUSION： The new SPIO（Fe2O3 coated by a thin layer of 3-aminopropyltriethoxysilane） had no significant toxicity on cells. MSCs still could be labelled with the new SPIO directly and high efficiently without the use of poly-L-lysine or other additional transfecting agents. The transplanted cells could be well imaged and traced in vivo.