磷酸钙人工骨联合雷洛昔芬修复兔下颌骨缺损

背景：雷洛昔芬是第3代选择性雌激素受体调节剂,可减少骨量的丢失,增加骨组织中的矿物质含量,降低骨折风险。目的：观察雷洛昔芬结合自固化磷酸钙人工骨修复兔下颌骨缺损的效果。方法：在36只新西兰大白兔左侧下颌骨制作8 mm×4 mm×3 mm的缺损模型,随机分组,实验组12只植入自固化磷酸钙人工骨,并给予雷洛昔芬7.5 mg/（kg·d）;药物组12只给予雷洛昔芬7.5 mg/（kg·d）;人工骨组12只植入自固化磷酸钙人工骨。分别于治疗4,8,12周取下颌骨标本,免疫组织化学法观察骨形态发生蛋白2的表达,激光共聚焦显微镜观察转化生长因子β的表达。结果与结论：实验组治疗后4,8周时的骨形态发生蛋白2免疫组织化学染色阳性细胞数明显高于药物组与人工骨组,治疗后12周时实验组骨改建基本完成,骨形态发生蛋白2免疫组织化学染色阳性细胞数目低于其他两组。实验组转化生长因子β免疫荧光染色表达为逐步升高,到第8周时达到峰值,而药物组和人工骨组的转化生长因子β免疫荧光表达从4-12周一直呈上升状态,趋近于最高峰。说明雷洛昔芬能够促进自固化磷酸钙人工骨在骨缺损过程中骨形态发生蛋白的早期表达及早期骨痂的形成,加快骨缺损修复。

Raloxifene combined with calcium phosphate cement for repair of rabbit mandibular defects

BACKGROUND：Raloxifene is the third generation of selective estrogen receptor modulators, which can decrease bone loss, increase bone mineral content, and reduce fracture risk. OBJECTIVE： To study the effects of raloxifene combined with self-setting calcium phosphate cement on the repair of rabbit mandibular defects. METHODS：Totaly 36 New Zealand white rabbits were selected to prepare 8 mm×4 mm×3 mm mandibular defect models, and then randomized equaly into experimental group （raloxifene, 7.5 mg/kg per day, combined with self-setting calcium phosphate cement）, drug group （raloxifene, 7.5 mg/kg per day）, artificial bone group （self-setting calcium phosphate cement）. Rabbits were sacrificed 4, 8 and 12 weeks later, respectively, for measurement of bone morphogenetic protein 2 using immunohistochemistry method and transforming growth factor β using a laser scanning confocal microscope. RESULTS AND CONCLUSION：After 4 and 8 weeks, the expression of bone morphogenetic protein 2 was obviously higher in the experimental group than the drug and artificial bone groups; after 12 weeks, bone remodeling was basicaly complete in the experimental group, and the expression of bone morphogenetic protein 2 became lower than that in the other two groups. The expression of transforming growth factor β in the experimental group was gradualy increased and reached the peak at 8 weeks, while in the drug and artificial bone groups, the expression of transforming growth factor β exhibited an increasing trend within 4-12 weeks, which was close to the peak. These findings suggest that raloxifene can promote early expression of bone morphogenetic proteins and early calus formation as wel as accelerate the repair of bone defects with calcium phosphate cement.