组织工程骨再生修复骨缺损的实验研究

The expremental study of bone repair in radias defect of the rabbits by bone tissue engineering re-generation

目的：观察不同浓度成骨细胞于三维胶原凝胶载体中植入体内的骨再生效果，确立成骨细胞于三维胶原凝胶载体中植入的最佳有效浓度。方法：采用胶原酶、胰蛋白酶消化方法分离、培养成骨细胞，然后按10^7、10^6、10^5、10^4/ml将成骨细胞包埋于I型胶原凝胶载体中植入兔桡骨骨缺损区域，于术后1－8周采用形态学观察、双能量X线骨密度测量、电镜观察其骨再生过程。结果：成骨细胞按10^7、10^6、10^5、10^4/ml植入组和对照组骨缺损桥接率于术后4周时分别为40％、65％、31．25％、5．55％、5％，植入8周时分别为41．67％、75％、37．5％、10％、8．33％；成骨细胞按10^7、10^6、10^5、10^4/ml植入组和对照组于术后6周骨密度分别为0．112±0．018、0．159±0．033、0．122±0．039、0．066±0．002、0．067±0．009，术后8周骨密度分别为0．150±0．059、0．173±0．041、0．145±0．023、0．103±0．023、0．102±0．033。扫描电镜观察成骨细胞植入1周时细胞呈圆形或椭圆形，其周围可见大量呈疏松排的胶原纤维；植入3周时已经有骨陷窝形成，骨陷窝中的成骨细胞突起多、细、短；植入5周时骨陷窝已钙化，骨小管很清晰；成骨细胞突起变少、变粗、变长。结论：成骨细胞于三维胶原凝胶中按10^7、10^6、10^5/ml均有明显促骨再生效果，其最佳细胞密度为10^6/ml。

Methods Osteoblasts free from the calvaria of fetal rabbits by sequential enzymatic digestion were transplanted into the radias defect of the adult rabbits after 6-8 days in culture, They were embedden in the type I collagen gel in the concentration of 10~7, 10~6, 10~5, 10~4/ml , Bone repair was evaluated by X - ray, bone density and scanning electron microscopy. Results Bone union rat of radias transplanted 10~7, 10~6, 10~5, 10~4/ml osteoblast /ml was 40% , 65% , 31. 25% , 5. 55% at 4 weeks after transplanting, and 41. 67% , 75% , 37. 5% , 10% at 8 weeks after transplanting. Bone density of radias defect transplanted 10~7, 10~6, 10~5, 10~4/ml osteoblast / ml was 0. 112 ±0. 018, 0. 159 ±0. 033, 0. 122±0. 039, 0. 066 ±0. 002 at 6 weeks after transplanting and 0.150±0.059, 0.173 ±0.041, 0.145±0.023, 0. 103±0. 023 at 8 weeks after transplanting. By scanning electron microscope observation, at one week after transplanting, there are only round cells and uncalcified extracellular matrices (ECM). At 3 weeks after transplanting, bone lacuna has formed, ECM has not fully cacified, Osteoblasts on the lacuna have many short thin protoplasmic processes. At 5 weeks after transplanting, ECM has fully cacified, Osteoblasts on the lacuna have less longer protoplasmic processes which penetrate the adjacent mineralized matrix via canaliculae. Conclusions Transplantation of allogeneic fetal osteoblast can stimulate bone defect repair, The optimal concentration of osteoblast at implant is 101~6 cells /ml.