骨形态发生蛋白复合明胶羟基磷灰石涂层多孔钛修复兔骨缺损的实验研究

目的 研究骨形态发生蛋白-2（BMP-2）复合明胶羟基磷灰石（HA）涂层多孔钛对兔股骨远端骨缺损的修复作用。方法 以多孔钛粉末为原料，制备三维多孔结构钛载体，然后运用碱热处理＋模拟体液等化学方法进行HA涂层，制备具有三维空间结构的HA涂层多孔钛复合材料。36只新西兰兔随机分为实验组及对照组，制备股骨远端圆柱状骨缺损模型，实验组植入复合BMP-2的HA涂层多孔钛材料，对照组单纯植入HA涂层多孔钛材料。分别于6、12、24周取材通过组织学和生物力学分析。结果组织学观察显示于各时间点实验组骨生成均不同程度优于对照组；生物力学测试显示在推出实验中所有样品的剪切应力都随时间增长而增大。其中在6周、12周实验组多孔钛在所有时间点均表现出了比对照组高得多的剪切力（P〈0．05），在24周实验组和对照组差异无统计学意义（P〉0．05）。结论 BMP-2复合明胶HA涂层多孔钛较单纯HA涂层多孔钛植入早期具有更良好的生物相容性、骨传导性及骨诱导性，可成功修复兔股骨远端骨缺损。

Bone morphogenetic protein-2 and gel complex on hydroxyapatite-coated porous titanium to repair defects of distal femur in rabbits

Objective To assess the osseointegration capability of BMP-2 andgel complex on hydroxyapatite-coated porous titanium in repair of defects of distal femur in rabbits. Methods The porous titanium implants were made by sintering titanium powder at high temperature. The hydroxyapatite-coated porous titanium was prepared by alkali and heat treatment. The gel was used as a delivery system to prolong the effect of BMP-2. The implants were inserted into the defects of distal femur in rabbits. The animals were sacrificed 6, 12 and 24 weeks after implantation to accomplish histological and biomechanical analyses. Results According to the histological analysis, the osseointegration was better in the BMP-2 group than in the HA-coated porous titanium group. In the push-out experiment, the shear stress increased in all the samples in a time-dependent manner. There were statistical differences in the shear stress between the 2 groups at 6 and 12 weeks postoperatively but not at 24 weeks. Conclusions BMP-2 and gel on hydroxyapatite-coated porous titanium has a good early osseointegration capability of repairing the bone defects in rabbits. It may be a fine biomaterial for future clinical application.