【作者】 周江；

【导师】 陈槐卿；

【作者基本信息】 四川大学 ， 生物医学工程， 2003， 硕士

【摘要】 骨组织工程学是利用组织工程学原理对骨组织缺损进行修复或重建。自从利用骨组织工程学构建骨移植替代物以来，研究者发现移植物成骨作用缓慢，不能和支架材料降解作用相匹配，主要有两个原因：(1)种子细胞成骨作用较慢；(2)营养血管生长缓慢，由于毛细血管网向材料内部生长速度非常缓慢，种子细胞因为缺乏营养供应而不能爬行入材料深部，使得骨沉积作用不能有效代替降解的生物材料。 近年来，研究人员发现内皮细胞可以分泌骨形态发生蛋白(BMP)，促进成骨分化，并刺激成骨细胞及其前体细胞分泌血管内皮生长因子(VEGF)，而VEGF可以促进内皮细胞增殖和血管发生，也具有明显促成骨作用。由此我们可以假设如果将骨髓基质细胞和内皮细胞联合种植在生物复合材料上构建组织工程化骨，则可能促进成骨过程的同时又加速局部血管生成，满足成骨过程的营养需要。 在体外实验中，我们发现内皮细胞作用下骨髓基质细胞(实验组)形成钙化结节明显多于未处理的骨髓基质细胞(对照组)，且在培养的第14d和21d时，实验组的碱性磷酸酶(ALP)活性和骨钙素(OCN)分泌量均高于对照组约2-3倍，表明内皮细胞对骨髓基质细胞具有促成骨作用。 在体内实验中，我们将大鼠骨髓基质细胞和人脐静脉内皮细胞种植在左旋聚乳酸／β-磷酸三钙(PLLA／β-TCP)多孔复合支架材料上作为实验组，种植骨髓基质细胞在该材料上作为对照组，发现实验组材料内毛细血管网形成情况要明显优于对照组，而且成骨过程明显增骨版基质细胞和内皮细胞联合种植构建雳旦织口二程化骨的布开究一命仓文摘要快，表明骨髓基质细胞和内皮细胞联合种植于支架材料构建组织工程化骨有利于材料内部血管网形成，有可能解决种子细胞因缺乏营养供应而不能爬入材料深部成骨的问题。更多还原

【Abstract】 Bone tissue engineering is to restore and reconstruct the bone at the defect site under the principles of tissue engineering. Since constructing tissue-engineered bone, researchers find the osteogenic progress is very slow and can’t match the degradation of the scaffold. The most important reasons are: (1) Osteogenic progress of the seed cells is slow. (2) Nutritional capillary network grows into the scaffold very slowly. The seed cells can’t crawl deep into the scaffold because of lack of nutritional supply, so the deposit doesn’t match the degradation of the scaffold.Recently, researchers find that endothelial cells (ECs) can promote osteogenic progress and stimulate osteoblasts and osteoprecursor cells to produce vascular endothelial growth factor (VEGF) through producing bone morphogenetic protein (BMP). VEGF can stimulate proliferation of ECs and angiogenesis. So we assume that seeding marrow stromal cells (MSCs) and ECs onto biocomposite to construct tissue-engineered bone might promote osteogenesis and angiogenesis simultaneously, so as tosatisfy the nutritional need of osteogenesis.We find that under activation of ECs, MSCs (test group) produce more calcification nodules than those untreated (control group). After cultured 14 days and 21 days, respectively, The activity level of alkaline phosphatase (ALP) and osteocalcin (OCN) production of the test group are higer 2-3 times than those of the control group. These results prove that ECs can promote osteogenesis.In our in vivo studies, we seed rat marrow stromal cells (rMSCs) and human umbilical vein endothelial cells (hUVECs) onto poly(L-lactic acid)/p-tricalcium phosphate (PLLA/P-TCP) macroporous composite to be the test group, and seed rMSCs onto the same kind of composite to be the control group. We find the capillary network growth of test group is much better than that of control group, and so is the osteogenesis. These results suggest that co-seeding MSCs and ECs onto scaffold to construct tissue-engineered bone promote angiogenesis in the prosthesis, and the problem that calcification deposit can’t occur deep in the prosthesis because of lack of nutritional supply might be resolved.更多还原