磁标记干细胞-冻干骨治疗股骨头坏死修复机制的实验研究

项目名称： 磁标记干细胞-冻干骨治疗股骨头坏死修复机制的实验研究

项目编号： No.30801061

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 电工技术

项目作者： 董越

作者单位： 大连医科大学

项目金额： 19万元

中文摘要： 骨髓基质干细胞移植可以有效地治疗股骨头坏死。如何评价干细胞移植治疗效果和治疗机制是目前研究的热点问题。本研究应用内毒素+激素成功诱导股骨头坏死模型，从模型中提取骨髓基质干细胞，进行培养、传代、细胞活性等鉴定。采用新型的超顺磁性氧化铁颗粒直接标记提取自模型的骨髓基质干细胞，并确定25μml铁为最佳的体外标记浓度，可以进行MR成像同时不影响细胞的功能；该浓度标记的干细胞进行传代培养，铁颗粒在传代的干细胞中长期存在，并仍可以被MR检测到，随着传代次数的增加，干细胞内的铁含量逐渐减少。干细胞移植治疗股骨头坏死模型的MR研究发现，治疗测较非治疗侧股骨头的血供有所增加，组织病理学发现股骨头内新生血管增加，成骨细胞增加。磁标记干细胞在移植后2小时应用MR功能性技术检测到信号的变化，提示铁颗粒的存在。本研究初步认定激素性股骨头坏死模型干细胞提取、培养、传代、磁标记和体外MR示踪成像可行，磁纳米颗粒在一定时间内存在于干细胞中并可随细胞传代；MR仅在移植后的早期可以检测到含有磁纳米颗粒的干细胞存在。干细胞可以促进坏死股骨头的血供修复和成骨性修复，MR功能性成像技术可以间接反映这种修复过程。

中文关键词： 股骨头坏死;干细胞;磁标记;磁共振；修复

英文摘要： Abstract： The transplantaion of bone mesenchymal stem cells (MSCs) is a new method for treatment of femoral head necrosis. How to evaluate the effect of stem cell transplantation therapy and therapy mechanism is currently a hot issue.Using endotoxin and long hormone successfully induced osteonecrosis model.Successfully extracted stem cells from the model of bone marrow, which were cultured and passaged, and done cell activity and other identification. Using the new superparamagnetic iron oxide particles directly labeled MSCs extracted from the model,and determine 25μml iron in vitro was the best markers concentration,and MR imaging could be good without affecting cell function. Also found that stem cells labeled in 25μml iron concentration can be subcultured. Iron oxide particles in the passage of stem cells was long-term existence, and could still be MR detected. With the passage number increases, the iron content within the stem cells decreased. After stem cell transplantation for femoral head necrosis model MR study found that the blood supply in treatment side of the femoral head had increased, and histopathological findings showed new blood vessels within the femoral head, osteoblast cells increased. Magnetically labeled stem cells after transplantation could be detected MR functional sequences only 2 hours, suggesting the presence of iron oxide particles. The presence of iron oxide was not detected in other time. In this study, it was feasible to stem cell extraction, culture, passage, magnetic markers and in vitro MR imaging tracer in a preliminary model of femoral head necrosis. In vitro magnetic nanoparticles in a certain time was in the stem cells and with cell passage, but magnetically labeled stem cells after transplantation in vivo only could be detected MR signal change in the early post-transplant.Stem cells can contribute to blood supply repair and osteoblastic restoration in femoral head necrosis, through the functional MR imaging techniques can indirectly reflect the repair process.

英文关键词： femoral head necrosis;stem cell; magnetical label; MRI; repair