3D打印高效成骨、成血管双功能的个性化预制组织工程骨修复大体积颌骨缺损的研究

The repair of large-volume jaw defect has long been the difficult problem facing many oral clinicians. Based on the tissue engineering materials, research of osteogenesis and vascularization is the central problem of the bone tissue engineering, which currently is the hottest and most difficult focus, too. However, little has been reported about promoting osteogenesis and vascularization of the 3D printed, customized tissue-engineered scaffold by multiple strategies. Based on the preliminary studies, this project is planning to contrast various means of blood vessel bundle implant and study their influences on the angiogenesis and degradation rate of the 3D printed, pre-built vascular tunnels scaffold. Exploring the osteogenic and angiogenic influences of the fibrinogen combining with the heterodimeric BMP2/7-cop. BioCaP particles on the 3D printed tri-calcium phosphate scaffold. Studying the effects of co-culture of BMSCs and EC together with the BMP and/or the axial vascular bundle on the customized pre-built vascular channels tri-calcium phosphate scaffold in osteogenesis and angiogenesis/ vasculogenesis when prefabricated in the minipigs' latissimus dorsi. Multiple testing measures, like molecular biology, biomechanics, imaging, histology, angiography, et al. will be utilized and we will sum up the most efficient method in the induction of osteogenesis and vascularization. Finally, we will obtain the evaluation criteria that a successful restoration of minipigs' mandibular defect by transferring the flap will be made, to reveal the best means to reconstruct the mandibular defects, and to provide a reliable basis for clinical repair of bone defects.

大体积颌骨缺损的修复一直是口腔临床医生面临的难题。以组织工程材料为基础的骨化和血管化研究是骨组织工程研究的中心问题，也是目前研究的热点和难点。使用多策略诱导方式促进3D打印的个性化组织工程支架材料成骨及血管化的研究少有报道。本项目在前期研究基础上，拟对比多种血管束植入手段对预构血管通道的3D打印支架材料血管化及降解速率的影响；探索纤维蛋白原结合仿生BMP2/7异二聚体钙磷颗粒对3D打印的磷酸三钙支架材料成骨及血管化影响。在小型猪背阔肌内异位预制研究BMSCs及EC细胞结合BMP和或轴状血管束对预构血管通道的个性化磷酸三钙支架材料成骨及血管化影响。采用分子生物学、生物力学、影像学、组织学及血管造影等多手段检测方式，总结出目前最高效的诱导成骨及血管化的方法。最后以成功转瓣修复小型猪下颌骨大体积缺损为评价标准，揭示最优颌骨缺损修复手段，为临床修复骨缺损提供可靠依据。

大体积颌骨缺损的修复重建一直是临床医生面临的难题。本课题组前期利用骨组织工程技术异位构建大块组织工程骨可较好地修复恒河猴下颌骨缺损。然而其中心血管化不佳、成骨较差。据此，本课题组创造性优化设计支架结构，形成含仿生血管通道骨修复支架。通过体外检测、异位植入和恒河猴下颌骨模型对比研究血管束植入、生长因子负载等对该骨修复支架成骨、血管化的影响。并筛选成骨、成血管双向诱导分化的脐带间充质干细胞最佳的共培养条件。现已确定该支架制备工艺、联合非结扎血管束及生长因子负载时成骨效果最佳，可较好地恢复缺损下颌骨的连续性及骨高度。确立了双向诱导分化脐带间充质干细胞成骨最优的共培养条件。这为后期优化构建可转化骨缺损修复材料奠定基础。