不同孔径的多孔磷酸钙骨水泥修复兔大段骨缺损的实验研究

发布时间：2018-05-17 22:10

本文选题：孔径 + 孔隙结构　；参考：《第四军医大学》2012年硕士论文

【摘要】：研究背景：各种原因引起的骨缺损的修复一直是骨科界所面临的难题。以往常采用异体骨移植的方法来修复骨缺损，但异体移植骨来源有限，而且易产生免疫排斥反应。随着组织工程学迅速发展，利用骨组织工程学的方法修复骨缺损成为一种全新的治疗模式，具有广阔的应用前景。支架材料、种子细胞、诱导因子为骨组织工程研究的三要素，而支架材料又是其基础环节。相关研究表明，材料的自身结构是影响材料机械性能和生物学性能的一项重要的形态学特性，是支架材料设计与选择所要考虑的重要因素之一；材料的结构参数包括孔型、孔径、孔隙率和连通性等等；其中材料孔径的大小对于细胞的增殖和黏附、新生骨组织形成等都有着重要的影响。因此，研究者们一直在探索有利于骨组织构建的最佳孔径大小。但是，至今为止，对于支架材料的最佳孔径选择仍然存在争论。本课题的前期实验结果显示不同孔径材料在非骨环境和松质骨缺损中诱导形成的新生骨组织在分布和数量上有明显差异的。本研究拟通过采用孔隙率相同、孔径不同的(200-300μm、300-450μm、450-600μm)的CPC材料修复兔大段骨缺损，评价不同孔径的CPC材料的骨缺损修复能力，从而筛选出适合的孔径，以期达到成骨能力与生物力学性能的良好统一,为未来临床应用提供科学依据。研究目的：探讨多孔磷酸钙骨水泥（CPC）孔径大小对其骨缺损修复能力的影响。研究方法：采用盐析法制备了孔隙率相同（68.3±3.3%）、孔型较均一的三种不同孔径的(200-300μm、300-450μm、450-600μm)多孔CPC材料，将三种不同孔径的材料分别植入兔大段桡骨缺损模型，术后4、12、24周分别进行大体观察、X线检查、血清碱性磷酸酶（ALP）检测、组织学观察和生物力学检测。研究结果：术后12周X线检查可见200-300μm孔径材料骨缺损区形成的骨痂较多,4、24周时X线检查结果各组差异不明显；4周时血清ALP检测200-300μm材料组高于其它组，差异具有统计学意义（P0.05），12、24周ALP检测三组差异无统计学意义；12周组织形态计量学分析显示200-300μm材料组新生骨的面积百分比最多，差异有统计学意义（P0.05），24周组织形态计量学分析结果提示，三组材料内新生骨面积百分比均增高，但差异无统计学意义（P0.05）；力学结果显示12周时200-300μm组材料的最大压缩载荷和弹性模量均好于其它两组（P0.05），24周时各组测得的最大压缩载荷和弹性模量差异不具有统计学意义。研究结论：孔径的大小可以影响骨生物材料在体内的成骨性能，本研究中小孔径材料在早期更利于成骨，，且更易达到成骨性能和力学性能的统一；而在晚期，不同孔径的材料在骨缺损内的成骨数量无显著差异，且材料植入区的力学强度无显著差异。
[Abstract]:Background: repair of bone defects caused by various causes has been a difficult problem in orthopedics. Allogeneic bone graft was used to repair bone defect, but allograft bone was limited in origin and prone to immune rejection. With the rapid development of tissue engineering, the method of bone tissue engineering to repair bone defects has become a new treatment mode and has a broad application prospect. Scaffold materials, seed cells and inducing factors are the three elements of bone tissue engineering, and scaffold materials are the basic link of bone tissue engineering. Related studies have shown that the structure of the material is an important morphological characteristic that affects the mechanical and biological properties of the material, and is one of the important factors to be considered in the design and selection of the scaffold material, and the structural parameters of the material include the pore shape. Pore size, porosity, connectivity and so on. The pore size of materials has an important effect on cell proliferation and adhesion, new bone tissue formation and so on. As a result, researchers have been exploring the optimal pore size for bone tissue construction. However, up to now, there is still controversy about the optimum pore size choice of scaffold materials. The experimental results show that the distribution and number of new bone tissue induced by different pore size materials in non-bone environment and cancellous bone defect are significantly different. The aim of this study was to evaluate the ability of repairing large segments of bone defects of rabbits by using CPC materials with the same porosity and different pore sizes (300-450 渭 m ~ 450-600 渭 m), so as to screen out the appropriate pore size. In order to achieve a good unity of osteogenic ability and biomechanical properties, and provide scientific basis for clinical application in the future. Objective: to investigate the effect of pore size of porous calcium phosphate cement (CPC) on the ability of repairing bone defect. Methods: three kinds of porous CPC materials with the same porosity (68.3 卤3.3%) and uniform pore sizes (200-300 渭 m ~ 450 渭 m ~ 450-600 渭 m) were prepared by salt-out method. Three kinds of porous CPC materials with different pore sizes were implanted into rabbit radial defect model. Gross observation X-ray examination, serum alkaline phosphatase (ALP) detection, histological observation and biomechanical examination were performed 24 weeks after operation. Results: X-ray examination at 12 weeks after operation showed that 200-300 渭 m radius material bone defect area formed more callus at 24 weeks. The results of X-ray examination showed no significant difference in 24 weeks after operation. At 4 weeks, serum ALP detection of 200-300 渭 m material group was higher than that of other groups. The difference was statistically significant (P 0.05). There was no significant difference in 24 weeks ALP detection among the three groups. The histomorphometry analysis showed that the area percentage of new bone was the largest in the 200-300 渭 m group at the 12th week, and the difference was statistically significant. The results of 24 weeks histomorphometry analysis suggested that there was no significant difference between the two groups. The percentage of new bone area increased in all three groups. The mechanical results showed that the maximum compression load and elastic modulus of 200-300 渭 m group were better than those of the other two groups at 24 weeks. Conclusion: the size of pore size can affect the osteogenic properties of bone biomaterials in vivo. In this study, small pore size materials are more conducive to osteogenesis in the early stage, and more easy to achieve the unity of osteogenic and mechanical properties. There was no significant difference in the amount of osteogenesis in the bone defect between the materials with different pore sizes, and there was no significant difference in the mechanical strength of the implant area.
【学位授予单位】：第四军医大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.08

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