组织工程化骨修复兔桡骨缺损的实验研究

目的:探讨骨髓间充质干细胞复合脱钙骨基质和骨形成蛋白修复兔桡骨缺损的效果。方法:体外分离、培养骨髓间充质干细胞,复合于脱钙骨基质,以骨形成蛋白进行成骨化诱导。日本大耳白兔45只,随机分为3组,A组:骨髓间充质干细胞+脱钙骨基质+骨形成蛋白;B组:脱钙骨基质+骨形成蛋白;C组:空白组。行兔15 mm桡骨缺损修复。术后12周取桡骨标本,大体观察并手法评估3组桡骨缺损修复情况,组织学及生物力学测定植入材料融合情况。结果:术后12周,大体可见A组基本骨性愈合,融合组织质地硬,形态不规整;B组见少量骨痂形成,尚有部分缺损未愈合。C组骨缺损处见肉芽组织充填,未见骨痂形成。组织学观察Masson染色示A组大量软骨形成,靠近连接处可见新生骨小梁形成且处于成骨活跃期,软骨与骨组织之间过渡自然。B组可见部分新生骨小梁形成,材料骨小梁变细较少,断裂明显。C组未见新生骨小梁形成。生物力学测定A组的最大载荷、抗压强度和弹性模量分别为(87.8±9.8)N、(8.4±0.9)MPa及(187.5±8.2)GPa,均低于健侧组(112.3±11.2)N、(9.5±0.2)MPa及(210.5±15.9)GPa],且组间比较有统计学差异(P<0.05)。结论:骨髓间充质干细胞复合脱钙骨基质和骨形成蛋白修复兔桡骨缺损,优于应用脱钙骨基质和骨形成蛋白,早期生物力学强度低于正常骨组织。

Repair of radius defection by tissure engineering bone in rabbits

Objective: To discuss the repair of rabbits radius defection by using bone marrow stromal stem cells(MSCs)in conjunction with bone morphogenetic protein(BMP) and freeze-dried demineralized bone matrix(FDBM) as scaffold.Methods: MSCs were separated and cultivate in vitro,with FDBM as scaffold,osteogenesis was induced by BMP.Forty-five Japan white rabbits were randomly divided into three groups,Group A was MSCs+FDBM+BMP,Group B was FDBM+BMP,Group C was blank control group.The repairing of 15mm defection of rabbit radius was processed.Rabbits were killed at 12 weeks after operation.The general observation and imageology were used to assess the repairing condition.The implantation was estimated by using histology and tissue biomechanics methods.Results: The animals were executed at 12 weeks after operation,with general observation,the fusion mass character in group A was hard,the morphology was not regulation.Some bony callus can be seen in group B,and the defection was not repaired.Granulation tissue was filled in the radius defection,and any bony callus could not be seen.Histology observation of Masson staining showed there were large number of cartilage and newly born bone trabecular formation processed in bone active period near junction place in group A.Less newly born bone trabecular formation could be seen in group B and the FDBM bone trabecular was tapering,less and cracked.No newly born bone trabecular was seen in group C.Tissue biomechanics measurement: Maximum load,Compressive strength,Modulus of elasticity were(87.8±9.8)N,(8.4±0.9)MPa and(187.5±8.2)GPa in group A,less than the healthy side (112.3±11.2)N,(9.5±0.2)MPa(210.5±15.9)GPa],P<0.05.Conclusion: Repairing bone defect with tissue engineering bone is superior to using FDBM combine with BMP.Early stage biomechanic intensity is inferior to normal bone tissure.