调控3D打印水凝胶的理化特征促进间充质干细胞的成骨分化及其在骨修复中的应用

人工合成骨已成为临床上重要的骨修复材料，但其仍存在骨诱导能力弱、生物安全性差等诸多缺陷。以改变支架材料的机械强度以及化学基团构成来促进MSCs的成骨分化能力是改进上述缺陷的有效方案之一。课题组前期实验中发现通过改变钙离子浓度调节水凝胶的机械强度以及通过增加阿仑膦酸盐中的双磷酸基团可以促进BMSCs的成骨分化。本研究拟探索构建水凝胶材料最佳的Ca2+浓度和磷酸基团含量，通过协同调控材料的机械强度和化学基团有效促进MSCs的成骨分化，同时利用计算机辅助的3D打印技术制备复合水凝胶组织工程骨，能够成功修复兔骨缺损模型。通过本项目的研究，希望开发一种制备简单、快速、成本低廉，但成骨高效的骨缺损修复材料，为其进一步应用于临床奠定基础。

Synthetic bone grafts have become important materials in clinical bone repair and regeneration, but are associated with challenges such as weak osteogenic inductive activity and poor biology security. Promoting the osteogenic differentiation of mesenchymal stem cells (MSCs) by modifying the stiffness and chemical composition of the scaffold is an effective strategy to overcome the challenges. Previous experimental studies have shown that the osteogenic differentiation of MSC was enhanced by changing the phosphate concentration of alendronate and the Ca2+ concentration of the hydrogels. This study is supposed to optimize the concentration of phosphate and the best stiffness of hydrogel on the osteogenesis activity of encapsulated MSCs. Meanwhile, we want to fabricate the MSCs encapsulated alendronate-modified hydrogels by using 3D printing technology and evaluate its bone repair performances in vivo. The aim of this project is to develop a facile, fast and cheap scaffold material with high osteogenic activity for bone repair and regeneration in clinical applications.