臂板蛋白3A对兔下颌骨牵张成骨术后成骨效应的影响

Effect of semaphorin 3A on osteogenic effect of rabbit after mandibular distraction osteogenesis

目的观察臂板蛋白3A对兔下颌骨牵张成骨的成骨效应的影响。方法选择20只新西兰大白兔,建立单侧下颌骨牵张成骨模型,然后分为A组、B组各10只。A组单纯行下颌骨牵张成骨;B组于牵张期第1、5、10天在牵张间隙内注射臂板蛋白3A(500μg/kg)。两组分别于固定期第2、6周随机处死5只动物获取下颌骨标本。分别采用X线检查和组织HE染色观察两组下颌骨牵张区成骨情况。制作下颌骨切片,光镜下观察并计算骨小梁宽度(TNTB)、新生骨数量(NBV)。用DXA扫描两组下颌骨样本,获取成骨区骨密度(BMD)、骨矿物质含量(BMC)。采用生物力学实验检测两组下颌骨成骨区的最大载荷、刚度和总能量吸收。结果随着时间推移,两组的牵张间隙内均有新骨形成并矿化,B组成骨情况优于A组。A、B组牵张成骨固定期第6周时成骨区TNTB、NBV及成骨区硬度、最大载荷、能量吸收均高于同组第2周时,相同检测时点B组高于A组(P均<0.05)。A、B组牵张成骨固定期第6周时成骨区BMD、BMC均高于同组第2周时,B组第6周时BMD、BMC高于同期A组(P均<0.05)。结论臂板蛋白3A能有效促进兔下颌骨牵张成骨间隙内新骨形成,提高成骨效应。

Objective To investigate the effect of exogenous semaphorin 3 A on osteogenic effect of rabbit after mandibular distraction osteogenesis(DO).Methods Twenty New Zealand’s white rabbits were randomly divided into 2 groups:group A and group B,with ten in each,and then mandibular distraction osteogenesis models in rabbits were established.Semaphorin 3 A(500μg/kg)was injected into the distraction gaps of the rabbits from group B on day 1,5,and 10,while rabbits in the group A only underwent DO on one side of the mandible.Bone samples were obtained at the end of the 2 nd and 6 th weeks of the fixed period.The osteogenesis of two groups ware observed by X-ray and HE staining.Obtaining trabecular plate thickness(TNTB)and new bone volume(NBV)through mandibular section by light microsccope.Obtaining bone mineral density(BMD)and bone mineral content(BMC)of mandibular samples through DXA scanning.The maximum load,stiffness and total energy absorption of the area of mandibular osteogenesis were detected by Biomechanical experiment.Results Over the time,there were new bone osteogenesis and mineralization in both groups,and group B showed better bone formation than group A.The data of both groups showed better at the end of 6 th week than that at the end of 2 nd week in the fixed period based on the analysis of TNTB,NBV,the stiffness of the bone formation,the maximum load and total energy absorbtion.At the same time,the data of group B were superior to those of group A(P<0.05).The data of groups A and B showed better in BMD and BMC at the end of 6 th week than those at the end of 2 nd week in the fixed period.The BMD and BMC of group B were superior to those of group A at the end of 6 th week(both P<0.05).Conclusion Semaphorin 3 A could effectively promote the new bone formation and osteogenic effect of rabbits after mandibular distraction osteogenesis.