摘要
背景:植入材料的载体作用、细胞因子的缓释作用以及植入后利于血管、软骨、骨的长入,适当的孔隙度及材料内部的三维结构都是影响支架材料选择的因素。目的:拟运用丝素蛋白、牛骨形态发生蛋白及骨髓间充质干细胞来构建新型组织工程骨,通过脊柱融合实验对其进行生物力学分析。材料:清洁级4周龄雄性新西兰大耳白兔70只,丝素蛋白由苏州大学材料工程学院提供,牛骨形态发生蛋白由中国医学科学院提供。方法:取10只兔体外扩增骨髓间充质干细胞,接种复合于丝素蛋白/牛骨形态发生蛋白复合物上,构建组织工程骨。剩余60只兔随机分成5组:丝素蛋白/牛骨形态发生蛋白/骨髓间充质干细胞组、丝素蛋白/骨髓间充质干细胞组、丝素蛋白/牛骨形态发生蛋白组、单纯丝素蛋白组、空白对照组,12只/组。各组均咬除L5棘突建立植骨床,前4组植入对应移植物进行椎板间融合,空白对照组仅去皮质骨,不给予任何外植物。主要观察指标:X射线、三维CT及手触法检测脊柱融合情况;苏木精-伊红染色观察移植物骨组织生成情况;在轴向压缩、前屈、后伸、侧屈4种不同生理运动情况下生物力学性能测试结果。结果:①植入12周时,丝素蛋白/牛骨形态发生蛋白/骨髓间充质干细胞组100%融合,丝素蛋白/牛骨形态发生蛋白组、丝素蛋白/骨髓间充质干细胞组、单纯丝素蛋白组融合率分别为83.3%,25.0%,16.7%,空白对照组为0。②丝素蛋白/牛骨形态发生蛋白/骨髓间充质干细胞组丝素蛋白完全降解,新生骨组织已进入塑形期,向板层骨发展;丝素蛋白/牛骨形态发生蛋白丝素蛋白完全降解,新生骨组织以编织骨为主;丝素蛋白/骨髓间充质干细胞组骨岛数目较前增多,未见连续性新生骨;单纯丝素蛋白组新生骨增加不明显;空白对照组始终未见新生骨生成。③丝素蛋白/牛骨形态发生蛋白/骨髓间充质干细胞组、丝素蛋白/牛骨形态发生蛋白组体内植入的融合脊柱具有明显的稳定性,刚度、强度较好,与其余3组比较差异有显著性意义。结论:丝素蛋白是一种良好的细胞外基质材料,通过丝素蛋白体外构建的组织工程化骨植入体内进行脊柱融合是可能的。
BACKGROUND： The selection of scaffold materials is influenced by many factors, such as the implant vectors, the slow-release effect of the cytokines, the promotion effect on the growth of blood vessel, cartilage and bone after implantation, the suitable porosity, and three-dimensional structure as well. OBJECTIVE： To construct new tissue engineered bone with bone marrow mesenchymal stem cells （MSCs）, bovine bone morphorgenetic protein （BMP） and silk fibroin （SF）, and to explore the biomechanics of the constructed bone by spinal fusion.MATERIALS： Seventy male New Zealand white rabbits, of 4 weeks old and clean grade, were used in this study. SF was offered by Soochow University Materials and Engineering College, bovine BMP was purchased from Chinese Academy of Medical Sciences. METHODS： Tissue engineered bone was constructed in ten rabbits by inoculating MSCs, which had been amplified in vitro, onto the SF/BMP composites. Other 60 rabbits were separated into five groups （12 rabbits one group） at random： SF/BMP/MSCs group, SF/MSCs group. SF/BMP group, pure SF group, and blank control group. L~ spinous process was resected to establish the bed of bone graft, and the former four groups were implanted with corresponding grafts for the intercentrum process fusion posteriorly. In the blank control group, the bone decortieation was only performed without any graft. MAIN OUTCOME MEASURES： Spinal fusion was determined by radiography, three-dimensional CT and manual palpation method; Hematoxylin-eosin stain was employed to observe the histogenesis of bone graft; Biomechanical testing was performed at axial compression, flexion, extension and lateral bending. RESULTS： At week 12 of the implantation, 100% spinal fusion rate was achieved in the SF/BMP/MSCs group, 83.3% in the SF/BMP group, 25% in the SF/MSCs group, 16.7% in the pure SF group, and 0 in the blank control group. Both SF/BMP/MSCs and SF/BMP exhibited complete degradation, but the former developed the lamellar bone and the latter trended to the woven bone; There were many bone islands but no successive new bone in the SF/MSCs group; No bone formation was observed in the blank control group. SF/BMP/MSCs and SF/BMP showed significantly better spinal fusion than other three groups. CONCLUSION ： SF is a kind of good extracellular matrix materials. It is feasible to construct tissue engineered bone with bone marrow MSCS, bovine BMP and SF for the spinal fusion in vivo.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2008年第27期5201-5208,共8页
Journal of Clinical Rehabilitative Tissue Engineering Research
