三维打印具有促进成骨/成血管效应的掺锂生物活性玻璃陶瓷支架用于颌骨大尺寸缺损修复及机制研究

As for numerous patients with jaw large size defects, the morphological and occlusal function reconstruction of the defect region may be very important to improve the survival quality of patients. It proposes higher requirements and challenges on the properties of bone graft materials. The bioglass scaffolds fabricated with traditional methods which possess poor mechanical properties and insufficient osteo/angio-stimulation activity, cannot meet the demand of the morphological/functional reconstruction. In present project, bioactive glass-ceramic scaffolds will be fabricated using 3D printing method, in which the controlled preparation of shape could meet the demand of jaw morphological reconstruction, and the controlled preparation of pore structure could optimize the mechanical properties. The incorporation of lithium ion into the porous scaffolds may achieve bidirectional inducing function on osteogenesis and angiogenesis. The regulative effects of lithium ion on osteogenesis and angiogenesis will be evaluated via control release of lithium ion from the porous scaffolds. Moreover, Wnt/β-catenin signaling pathway is acted as key signaling pathway, and its crosstalk and cascade with MAPK signaling pathway and PI3K/Akt signaling pathway will be evaluated in vitro. In canine alveolar cleft animal models, the regulative effects of 3D printing lithium doped bioglass scaffold that perfectly matches defect morphology on osteogenesis and angiogenesis will be revealed in vivo. It may provide theoretical basis for lithium-doped bioactive glass-ceramic scaffolds applied for jaw large size defect repair, and provide a new method and strategy for jaw large size defect repair.

临床上众多的颌骨大尺寸缺损患者中，缺损区域形态重建及咬合功能重建对于提升患者生存/生活质量至关重要，对骨修复材料性能提出更高的要求和挑战。传统方法制备的生物活性玻璃支架力学性能不理想及成骨/成血管诱导活性有限无法满足其形态/功能重建要求。本课题拟采用3D打印制备生物活性玻璃陶瓷多孔支架，通过形态可控制备满足颌骨形态重建需求，通过孔结构调控优化支架力学性能。并掺杂锂离子到多孔支架使其兼具成骨/成血管双向诱导功能；通过研究锂离子的可控释放探求其调控成骨/成血管细胞学效应，以Wnt/β-catenin信号通路作为关键信号通路，研究其与MAPK成骨信号通路及PI3K/AKT成血管信号通路间级联反应及交互作用。在犬牙槽突裂动物模型中，评价与缺损形态完全匹配的3D打印多孔支架调控体内成骨/成血管效应，可望为掺锂生物活性玻璃支架应用颌骨大尺寸缺损修复提供理论依据，为颌骨大尺寸缺损修复提供新的方法和策略。

临床上众多的颌骨大尺寸缺损患者中，缺损区域形态重建及咬合功能重建对于提升患者生存/生活质量至关重要，对骨修复材料性能提出更高的要求和挑战。传统方法制备的生物活性玻璃支架力学性能不理想及成骨/成血管诱导活性有限无法满足其形态/功能重建要求。本项目以目前国际广泛研究和应用的“CaO-SiO2-P2O5”系统生物玻璃陶瓷（BGC，摩尔比70Si-25Ca-5P）为基础，采用溶胶-凝胶方法，通过掺入LiCl替代部分Ca，形成凝胶后在800°C下煅烧，过筛制备出掺锂生物玻璃陶瓷粉体，进一步结合3D打印技术制备掺锂生物活性玻璃陶瓷支架材料；系统阐明掺锂生物活性玻璃陶瓷直接调控血管内皮细胞体外成血管效应以及通过BMSCs外泌体介导的旁分泌机制间接调控血管内皮细胞体外成血管效应；同时探讨掺锂生物活性玻璃陶瓷通过BMSCs外泌体介导的旁分泌机制调控巨噬细胞免疫状态的作用；在兔标准骨软骨缺损动物模型证实3D打印掺锂生物陶瓷调控体内骨再生的生物学作用。研究证实在生物玻璃陶瓷基础上掺杂锂离子可进一步促进内皮细胞增殖、迁移体外成管能力及成血管相关因子表达，Wnt/β-catenin、AKT和NF-kB信号通路参与了以上过程并存在级联交互作用；进一步研究证实掺锂生物活性玻璃陶瓷的锂离子释放可以通过外泌体miR-130a/PTEN/AKT信号通路促进BMSCs与内皮细胞之间信息交换，从而间接促进内皮细胞成血管作用；此外研究发现掺锂生物活性玻璃陶瓷可通过BMSCs外泌体介导的旁分泌途径激活miR-130a/PTEN/AKT信号轴促进巨噬细胞M2型极化，同时抑制巨噬细胞破骨向分化；体内实验证实，3D打印空心管结构掺锂生物活性玻璃陶瓷支架可促进体内血管新生。本研究通过借助生物玻璃陶瓷锂离子掺杂及3D打印技术协同提升生物陶瓷成骨/成血管诱导活性，可望为掺锂生物活性玻璃支架应用颌骨大尺寸缺损修复提供理论依据，为颌骨大尺寸缺损修复提供新的方法和策略。