Objective: To evaluate the osteogenic effect of dextran sulfate/recombinant human bone morphogenetic protein 2/chitosan (DS/rhBMP-2/CS) combined with coralline hydroxyapatite (CHA) in repairing large segmental bone defects by radiographic feature.
Methods: Fifty-seven 24-week-old male New Zealand rabbits were prepared for establishing right radius bone defect model of 20 mm in length. In which 54 rabbits were randomly divided into 3 groups ( n=18), and the CHA, DS/rhBMP-2/CS/CHA, and rhBMP-2/CHA artificial bone grafts were implanted into the bone defect in groups A, B, and C respectively; the remaining 3 rabbits were implanted nothing as blank control group. After operation, the gross condition of the animals was observed; at 4, 8, and 12 weeks after operation, X-ray film observation, Micro-CT scanning, and three-dimensional reconstruction were performed to obtain the volume of the new bone.
Results: The experimental animals recovered well and were in normal condition. X-ray observation showed that the bone healing in group B was better than that in groups A and C at each time point. At each time point after operation, the X-ray scores of group B were significantly higher than that of group A and group C ( P<0.05); the scores of group C at 8 and 12 weeks after operation were significantly higher than that of group B ( P<0.05). Micro-CT scanning and three-dimensional reconstruction observation showed that at each time point after operation in group A, the bone defect area had less bone formation and poor osteogenesis; in group B, there were many new bone tissues in bone defect area, and the bone remodeling was well, and gradually closed to normal bone morphology at 12 weeks; in group C, there were many new bone tissues in bone defect area, but the bone formation was general. The new bone volume of group B was significantly higher than that of group A and group C ( P<0.05) at each time point after operation, and the score of group C was higher than that of group A at 8 weeks after operation ( P<0.05).
Conclusion: The osteogenic effect of DS/rhBMP-2/CS/CHA sustained-release artificial bone is much better than that of single CHA and rhBMP-2/CHA, which can provide a new idea for treating bone defect by using bone tissue engineering in the future.
目的: 通过影像学表现评价硫酸葡聚糖/重组人 BMP-2/壳聚糖（dextran sulfate/recombinant human BMP-2/chitosan，DS/rhBMP-2/CS）缓释微球联合珊瑚羟基磷灰石（coral hydroxyapatite，CHA），修复大段骨缺损的成骨效果。.
方法: 取 57 只 24 周龄雄性新西兰大白兔，制备右桡骨 20 mm 长骨缺损模型。将其中 54 只兔随机分为 3 组（ n=18），A、B、C 组分别将 CHA、DS/rhBMP-2/CS/CHA 和 rhBMP-2/CHA 人工骨植入骨缺损区域中；余 3 只兔不植入材料作为空白对照组。术后观察动物大体情况；术后 4、8、12 周取材行 X 线片观察，Micro-CT 扫描及三维重建获取新生骨体积。.
结果: 实验动物术后恢复良好，大体情况正常。X 线片观察示，B 组术后各时间点骨愈合情况均优于 A、C 组；术后各时间点 B 组 X 线片评分显著高于 A、C 组（ P<0.05）；术后 8、12 周 C 组评分高于 A 组（ P<0.05）。Micro-CT 扫描及三维重建观察示，术后各时间点 A 组骨缺损区新生骨组织少，成骨形态差；B 组新生骨组织多，骨缺损区骨塑形良好，12 周时逐渐接近正常骨形态；C 组骨缺损区新生骨组织较多，成骨形态一般。术后各时间点 B 组新生骨体积均显著高于 A、C 组（ P<0.05），术后 8 周 C 组评分高于 A 组（ P<0.05）。.
结论: DS/rhBMP-2/CS/CHA 缓释人工骨的成骨效果明显优于单纯 CHA 和 rhBMP-2/CHA，为未来应用骨组织工程方法临床治疗骨缺损提供了新思路。.
Keywords: Dextran sulfate; bone defect; chitosan; coralline hydroxyapatite; radiology; recombinant human morphogenetic protein 2.