复合基因重组人骨形成蛋白-2异种骨的研制及成骨活性研究

目的　研制新型具有诱导成骨活性的异种骨植骨材料。方法　在重组合异种骨 (RBX)基础上 ,以基因重组人骨形成蛋白 - 2 (rh BMP- 2 )取代从牛皮质骨中提取的牛 BMP,与去抗原牛松质骨载体 (BCB)复合 ,制成复合 rh BMP- 2的异种骨 (rh BMP- 2 / BCB) ;将 4周龄雄性 BAL B/ C小鼠 6 0只 ,随机分为实验组和对照组 ,于实验组小鼠左股部肌袋植入 rh BMP- 2 / BCB骨粒 ,对照组小鼠左股部肌袋植入 BCB骨粒 ,术后 7、14及 2 1天取材 ,通过组织学、骨计量学方法检测 rh BMP- 2 / BCB的诱导成骨活性。结果　 1实验组术后 7天在小鼠肌袋可诱导软骨生成 ,14天形成编织骨 ,2 1天改建成板层骨并形成大量骨髓 ;对照组于术后各时间点均未见有软骨及骨形成。 2实验组的碱性磷酸酶活性和钙含量均高于对照组 ,具有统计学意义 (P<0 .0 1)。结论　 rh BMP- 2 / BCB具有较好的骨诱导能力 ,是一种较理想的植骨材料

PREPARATION OF rhBMP-2/BCB RECONSTITUTED BONE XENOGRAFT AND ASSAY OF ITS OSTEOINDUCTIVITY

Objective To investigate a new grafting material of bone xenograft with strong bone inductive and conductive capacity. Methods Based on successful clinical application of the reconstituted bone xenograft (RBX), a new xenograft was made by combining recombinant human bone morphogenetic protein 2 (rhBMP 2) with antigen free bovine cancellous bone (BCB). Sixty male BALB/C mice aged 4 weeks were divided into study group of 30 and control group of 30 randomly. rhBMP 2 / BCB was implanted in the left thigh muscle pouch in the study group and BCB in the control group. The mice were sacrificed at 7 d, 14d and 21d after implantation. Inductivity of rhBMP 2/BCB was detected by histological observation and biochemical determination of the samples. Results Histological examination showed that rhBMP 2/BCB induced chondrogenesis on the 7th day, with woven bone formed on the 14th day, and lamellar bone and marrow on the 21st day, while BCB failed to induce chondrogenesis or osteogenesis on the 7th, 14th and 21st days. The alkaline phosphatase activities and calcium content in study group were higher than those in control group with significant difference ( P <0.01). Conclusion rhBMP 2/BCB is an ideal grafting material with strong bone inductive and conductive capacity without evoking immune reaction.