Application of octacalcium phosphate for bone substitutes and a carrier for bone morphogenetic protein

人工合成的磷酸八钙(OCP)如果植入小鼠的骨膜下区域，可以增强骨吸收。这种植入的QCP可能被多核巨细胞吸收，这些巨细胞与破骨细胞具有一些超微结构特征，并随着时间的推移被骨取代。我们推测OCP可以作为一种有效的骨替代材料。为了验证这一假说，本研究旨在调查OCP.n植入是否促进了大鼠颅骨缺损的骨修复。将大鼠分为两组：OCP处理组和未处理对照组。每组6只大鼠分别于植入后4、12、24周固定。在顶骨制作全层标准化环钻缺损区，在缺损区植入人工合成的骨钙素。经过放射学检查后，标本进行脱钙和组织学处理。与对照组相比，OCP植入显著促进了骨修复。统计学分析显示，在第4周至第12周，颅骨缺损区内的放射性不透明区域增加。组织学上，第4周植入的OCP上已有骨形成，沿破损边缘已有骨形成。12周时，植入的OCP周围有新生骨形成。24周时，缺损处几乎完全被骨填充。在对照组中，仅在缺损区边缘观察到骨形成。目前的结果表明，OCP可以作为一种有效的骨替代材料。

Synthetic octacalcium phosphate (OCP) enhances bone lbrmation if implanted into the subperiosteal region of murine bone. Such implanted QCP may be resorbed by the multinucleated giant cells which share some ultrastmctural characteristics with osteoclasts and replaced by bone with time. We hypothesized that OCP could be used as an effective bone substitute. To test this hypothesis, the present study was designed to investigate if bone repair in a rat skull defect is enhanced by the implantation of OCP.Rats were divided into two groups : OCP-treated animals and untreated controls. Six rats from each group were fixed at4, 12, and 24 weeks after implantation. A full-thickness standardized trephine defect was made in the parietal bone and synthetic OCP was implanted into the defect. After being examined radiographically, the specimens were decalcifled and processed for histology.OCP implantation significantly promoted bone repair compared to the controls. A statistical analysis showed an increase in the area of radiopacity within the skull defect between week 4 and week 12. Histologically, bone was formed on the implanted OCP and along the defeut margin atweek4. At week 12, the implanted OCP was surrounded by newly formed bone. At week 24, the defect was almost completely filled with bone. In the control, bone formation was observed only along the defect margin.The present results demonstrate that OCP could be used as an effective bone substitute.