NPP/C-HA/rhBMP-2复合支架修复兔股骨缺损的实验研究

Experimental study of repairing rabbit femur defect with NPP/C-HA/rhBMP-2

目的:探讨NPP/C-HA/rhBMP-2人工骨在实验兔体内的成骨效果。方法:在兔股骨远端做直径7 mm、深10 mm的骨缺损模型,根据缺损形状,制作含有rhBMP-2的NPP/C-HA人工骨,缺损处不植入材料作为空白组,植入NPP/CHA人工骨为对照组,植入NPP/C-HA/rhBMP-2人工骨为实验组。第4、8、12周时,通过锥形束CT(CBCT)、H-E染色及Masson染色,观察各组成骨效应;检测各组血清中碱性磷酸酶(ALP)活性及组织中OCN阳性染色,确定缺损处成骨分化及骨成熟程度。采用SPSS 18.0软件包对数据进行统计学分析。结果:大体标本显示,实验组12周时缺损处修复完全,未见炎症、排斥等免疫反应。CBCT显示,12周时,对照组从骨缺损边缘到中心处骨密度增高,但边界仍在;加入rhBMP-2后的实验组效果更加明显,新生骨与周围宿主骨基本一致,边界消失。第8、12周时,实验组HU值显著高于对照组及空白组(P<0.05)。H-E染色及Masson染色显示,第8、12周时,实验组较对照组及空白组有明显的新生骨形成。第8周时,各组血清ALP活性升高,实验组ALP水平显著高于其他组(P<0.05)。OCN免疫组织化学IHC阳性染色显示,实验组较对照组、空白组更明显(P<0.05)。结论:NPP/C-HA/rhBMP-2具有良好的组织相容性、骨诱导性、骨传导性和成骨性,有望成为骨缺损修复良好材料。

PURPOSE: To investigate the osteogenic effect of nano-grade pearl powder(NPP)/chitosan-hyaluronic acid(C-HA)/recombinant human bone morphology protein-2(rhBMP-2) artificial bone. METHODS: A bone defect model with a diameter of 7 mm and a height of 10 mm was made at the distal end of the femur. NPP/C-HA stent containing rhBMP-2 was prepared according to the shape of the defect. No material was implanted in the defect as blank group. NPP/C-HA was used as the control group, NPP/C-HA/rhBMP-2 was implanted into the experimental group. At 4 weeks, 8 weeks, and 12 weeks, the bone effects of each component were detected by cone-beam CT(CBCT), H-E and Masson staining. Serum ALP activity and OCN in tissues to determine the osteogenic differentiation and osteogenesis maturity were detected. SPSS 18.0 software package was used for statistical analysis. RESULTS: At 12 weeks, the defect was completely repaired in the experimental group. No immunological side effects such as inflammation and rejection were observed. At8 and 12 weeks, CBCT showed that the experimental group had a higher CT value(Hounsfield units, HU) compared with the control group and the blank group(P<0.05). H-E and Masson staining showed that the experimental group had obvious new bone formation compared with the control group and the blank group at 8 weeks and 12 weeks, and ALP activity of the experimental group was significantly different from the control group and the blank group at 8 weeks. OCN immunohis-tochemical scoring of the experimental group was significantly different from the control group and the blank group(P<0.05). CONCLUSIONS: NPP/C-HA/rhBMP-2 has good tissue fusion, osteoinductivity, osteoconductivity and osteogenicity, which is expected to provide more effective treatment for bone repair.