Runx2基因转染对兔下颌骨牵张成骨的影响

Runx2 in vivo Gene Therapy Promotes Bone Regeneration in Rabbit Mandibular Distraction Osteogenesis

目的 :探讨在兔下颌骨牵张成骨过程中,Runx2基因参与牵张过程对新骨再生的影响。方法 :选用32只新西兰白兔成功建立单侧下颌骨牵张成骨模型,随机分为实验组和对照组。牵张结束时,实验组牵张间隙内注入转染重组腺病毒(Ad5-Runx2),对照组牵张间隙内注入等体积无菌生理盐水。于牵张结束后4周末处死全部实验动物。利用组织学、影像学、双能X线(DXA)和生物力学分析等方法,对获取的下颌骨牵张标本进行检测分析。结果:三维CT重建、组织学及DXA结果证实,实验组牵张间隙内新骨生成、新骨密度和矿化含量均明显高于对照组;三点弯曲试验分析显示实验组牵张间隙最大载荷明显高于对照组。结论:Runx 2-in vivo基因治疗能够有效促进下颌牵张成骨过程中的新骨再生。

Objective： To investigate the effects of Runx2 in-vivo gene therapy on new bone regeneration during distrac- tion osteogenesis in rabbit mandibula. Methods： 32 New Zealand maturity male rabbits were established to become the animal model of mandibular distraction osteogenesis, all these rabbit models were divided into experimental （n=16） and control group （n=16） randomly. At the last day of the distraction, Ad5-Runx2 was injected into the distraction gap of ex- perimental group rabbits, while in the control group, injection with the same dose of normal saline. At the end of four weeks after injection, all animals were sacrificed and the distracted mandibles were harvested. Histological, radiological observations, dual energy X ray （DXA） and biomechanical examination were used for evaluation. Results： Three-dimen- sional CT reconstruction images and histological analysis confirmed that the amount of the new bone forming and bone mineral density in the distraction gap of experimental group was significantly higher than the control group. DXA and three-point bending experiment results analysis also showed that the bone mineral density, bone mineral content and maxi- mum load of the distraction gap of experimental group was significantly higher than the control group. Conclusion： Runx2- in vivo gene therapy can effectively promotes the bone regeneration in rabbit mandibular distraction osteogenesis.