纳米材料支架与骨髓间充质干细胞构建纳米骨修复兔股骨头坏死

摘要 背景：清华大学材料系制备的纳米晶胶原基骨修复材料的化学性能和物理性能均符合人体内环境要求，具有良好的生物相容性。 目的：利用纳米材料和组织工程技术，探索骨髓间充质干细胞和纳米晶胶原基骨修复材料在骨坏死修复中的效果。 方法：制备骨髓间充质干细胞与纳米骨复合体。取46只新西兰大白兔建立双侧股骨头坏死动物模型，随机分为3组。假手术组不做任何治疗；单纯纳米骨植入组植入纳米骨；纳米骨+骨髓间充质干细胞组植入复合了干细胞的纳米骨。对植入后4，8，12周的股骨头行影像学观察以及组织学观察。 结果与结论：X射线检查：植入后12周，假手术组兔股骨头有塌陷；单纯纳米骨植入组充填区与周围组织区别不明显，周边有新生骨小梁；纳米骨+骨髓间充质干细胞复合体植入组充填区近似周围组织，充填区分布有骨小梁。组织学观察：4周时，假手术组股骨头坏死区无明显变化，其他两组植入物降解和新骨替代；8周时，假手术组股骨头负重区软骨面部分缺损，其他两组坏死区初步修复，可见成骨和材料降解；12周时，假手术组坏死区仍未修复，部分股骨头有塌陷，其他两组坏死区修复，纳米骨+骨髓间充质干细胞植入组骨小梁结构形成。结果表明，单纯纳米骨植入组和纳米骨+骨髓间充质干细胞植入组在股骨头坏死成骨方面效果优于假手术组，纳米骨+骨髓间充质干细胞植入组成骨更佳。

Nano-bone composite of bone marrow stromal stem cells and nano-material scaffold in repairing rabbit femoral head necrosis

Abstract BACKGROUND: The chemical properties and physical properties of nano-hydroxyapatite collagen (nHAC), prepared by Department of Materials at Tsinghua University, for bone repair, are in line with environmental requirements in the human body, and nHAC has good biocompatibility. OBJECTIVE: To evaluate the effectiveness of bone marrow mesenchymal stem cells (MSCs) and nHAC in osteonecrosis of the femoral head by means of nano-materials and tissue engineering technology. METHODS: MSCs and nHAC were mixed to prepare a complex. Bilateral osteonecrosis of the femoral head models were established in 46 New Zealand rabbits and then were randomly divided into 3 groups. Sham-operation group received no treatment; nHAC group was implanted with nHAC; nHAC+MSCs group was implanted with the complex of nHAC+MSCs. Imageology and histology changes of femoral head were investigated at 4, 8, 12 weeks after operation respectively. RESULTS AND CONCLUSION: X-ray examination showed that at 12 weeks after implantation, the femoral head collapse was found in sham-operation group; there was no obvious difference between implanting area and surrounding tissue after nHAC implantation, new bone trabeculae was around; in nHAC+MSCs group, the implanting area was similar to the surrounding tissue, and trabecular bone distributed. Histological detection showed that: at 4 weeks after operation, the sham-operation group presented no significant changes in defect area, while nHAC degradation and new bone formation were observed in nHAC group and nHAC+MSCs group; at 8 weeks after operation, the articular cartilage of sham-operation group was defected while osteogenesis and nHAC degradation were more obvious in nHAC group and nHAC+MSCs group; at 12 weeks after operation, there were collapse in some cases of sham operation group; At the same time, defect area was restored in nHAC group and nHAC+MSCs group, and trabecularism formed in nHAC+MSCs group. nHAC and nHAC+MSCs are superior to sham operation group in terms of the osteonecrosis of femoral head, especially nHAC+MSCs.