椎体后凸成形术中丝素增强型α-磷酸三钙/硫酸钙复合骨水泥及其成骨机制

The vertebrae bone defect repair materials can not meet the clinical requirements, that the materials could sustain the weight after coagulation instantly, since these materials has some different disadvantages. On the basis of long-term studies focused on the vertebrae bone defect repair materials, our project group has demonstrated that the silk fibroin (SF) can promote the osteoblastic differentiation and proliferation, accelerate the material absorption and bone regeneration, besides it can enhance the mechanical properties of calcium phosphate cement (CPC) when it was introduced in. However, the strength of the cement materials and vertebrae bone remodeling speed should still be improved for meeting the special requirements of vertebrae bone defect repair materials. This project introduced the calcium sulfate into the SF based CPC to develop the SF enhanced alpha- tricalcium phosphate/calcium sulfate cement composite(α-TCP/CSC).It has good biological activity and injectability. Its physicochemical properties, bio-safety and biocompatibility with osteoblast would be explored in vitro. The progress of its creeping substitution in vertebrae would be observed in vivo, and the mechanisms of promoting bone regeneration will also be discussed. The project will bring a new material for the vertebae bone defect repairing.

目前椎体内骨缺损修复材料因存在各种不足而不能满足即刻固化支撑修复椎体 内骨缺损的要求。在长期对椎体内骨缺损修复材料的研究基础上，本项目组证实丝素蛋白除 能增加磷酸钙骨水泥的力学性能，还能在体外促进成骨细胞增殖分化，加速骨水泥在椎体内 的替代进程，但骨水泥的强度和椎体内替代进程仍需进一步提高才能满足椎体内骨缺损修复 材料的特殊要求。本项目利用硫酸钙骨水泥材料力学强度好、在体内易降解的优点，将其掺 入丝素基磷酸钙材料中合成丝素蛋白增强型α-磷酸三钙/硫酸钙复合骨水泥，研制具有良好 生物活性注射型材料；体外评估其理化性能、检测其生物安全性、观察其与成骨细胞的作用， 体内观察其在椎体内的爬行替代，探讨该复合骨水泥促成骨的作用机制，为椎体内骨缺损的 修复提供新型的充填材料。

本课题在项目组制备丝素基磷酸钙骨水泥（SF/CPC）的基础上，将乙酰半胱氨酸（NAC）引入SF/CPC骨水泥体系制备NAC-SF/α-TCP骨水泥，并对其理化性能进行表征，结果显示NAC/SF/α-TCP骨水泥较SF/α-TCP强度明显提高，可达49.39±1.68（MPa）；骨水泥初凝时间为21.77±1.07（min），终凝时间为31.88±1.69（min）；水化产物主要为HA晶体。NAC/SF/α-TCP在体外可以增强骨缺损椎体的强度和刚度，体内修复大鼠股骨远端局限性骨缺损，显示具有较好的成骨能力，能促进材料周围新生骨的生成，进一步探讨了其促成骨可能的机制是通过上调Wnt/β-catenin信号通路来实现，为椎体以及其他部位的骨缺损修复材料的研究提供新思路。发表标注论文6篇，其中SCI收录3篇；申请发明专利1项；主要内容获华夏医学科技一等奖。