超顺磁性氧化铁标记内皮祖细胞治疗静脉血栓的示踪研究

Research of Endothelial Progenitor Cells Labeled with Superpara-Magnetic Iron Oxide in Treatment for Venous Thrombosis

目的研究血管内皮祖细胞（EPCs）磁标记后从尾静脉移植人静脉血栓模型中进行干细胞活体示踪，为EPCs促进深静脉血栓机化再通提供一种有效的监测方法。方法首先分离、培养并鉴定大鼠EPCs，配制新型超顺磁性氧化铁（SPIO）并体外标记EPCs。制作大鼠下腔静脉血栓模型并将其分为4组：移植SPIO标记的EPCs（SPIO组）、移植Dil标记的EPCs（Dil组）、移植单纯EPCs（对照组）、移植1mL培养基（空白对照组）。术后各组分别行磁共振成像（MRI）检查、血管性血友病因子（vWF）免疫组织化学染色、HE染色，并计数新生毛细血管数目。结果MRI观察到SPIO组的EPCs定向迁移至下腔静脉血栓内，呈团块状信号影，信号密度随时间延长而增强，第14～21d磁信号达到最强并由此开始转弱。移植术后取血栓标本行常规病理HE染色及免疫组织化学染色的结果显示，SPIO组、Dil组及对照组均可观察到血栓中出现大量新生毛细血管管腔，3组间新生毛细血管数目比较差异无统计学意义（P〉0．05），但这3组新生毛细血管数目明显多于空白对照组，差异均有统计学意义（P〈0．05）。结论相比较Dil标记的示踪方法，SPIO标记的EPCs移植入深静脉血栓中进行活体MRI示踪安全、无创、有效、可行。

Objective To research the magnetic labeled endothelial progenitor cells （EPCs） transplanted into the rat of venous thrombosis model through the tail vein and track transplanted stem cells in vivo, provide an effective moni- toring technology for promoting organization and recanalization of deep venous thrombosis. Methods Bone marrow- derived EPCs were extracted, purified, and identified, then labeled with the new SPIO particles. At the same time, the inferior vena cava thrombus models in rats were made, which were randomly divided into four groups： SPIO group （EPCs labeled with SPIO transplantation）, Dil group （EPCs labeled with Dil transplantation）, control group （simple EPCs transplantation）, and blank control group （1 mL medium transplantation）. After transplantation, the MRI, HE staining, and immunohistochemical staining were performed and the capillary density was counted under high-power microscope. Results The MR] showed that EPCs labeled with SPIO had migrated to the inferior vena cava thrombus and the mass of high signal shade was seen, with the extension of time, the signal strengthened gradually. On day 14-21, the signal became the strongest, then decreased gradually. The immunohistochemical staining and HE staining showed that there were a mass of the new capillary in the specimens of thrombus of the SPIO group, Dil group, and control group, the difference was not statistically significant among these three groups （P〉 0. 05）, but which was significant difference as compared with blank control group （P〈0. 05）. Conclusion Compared with EPCs labeled with Dil, itis an safe, noninvasive, and effective method that in vivo MRI tracing EPCs labeled with SPIO in treatment for deep venous thrombosis.