3D打印多孔可生物降解Fe-Mn金属材料在骨缺损修复中支撑和降解的调控与平衡研究

Bone defect is a commonly seen disease in clinical practice. Porous biodegradable Fe-based metal is considered to be a new type biomaterial, which can repair bone defect in load-bearing region and have important application value in clinic. However, the geometry and mechanical properties usually do not match with the region of bone defect. Furthermore, the regulation and balance of mechanical properties and degradation rate in vitro and in vivo remain a problem to be resolved. Based on the previous fabrication and analysis of 3D-printing porous Fe-Mn materials, our study will first investigate porous Fe-Mn metal bone scaffold with controlled geometry and quantitatively controlled mechanical properties, which are compatible with the bone defect area, using the relationship between Mn content and mechanical properties, and the constitutive equation between pore features and mechanical properties. Last but not least, the equilibrium relationship between mechanical properties and degradation rate, which can contribute to the bone remodel process in vivo, will be analyzed by studying the united quantitative regulation mechanism of Mn content and pore features to the degradation rate, and by investigating the dose-effect relationship between degradation rate and cytotoxicity. The project is expected to achieve 3D-printing porous biodegradable Fe-Mn metal with customized geometry and quantitatively controlled mechanical properties, balance the contradiction between support and degradation, and reveal the biomechanical principle of porous biodegradable metal which can contribute to bone remodeling in defect area. This project will provide new thought, new method and theoretical basis for bone regeneration in defect area.

骨缺损是临床常见病症，新型多孔可生物降解Fe基金属材料对于负重区骨缺损重建具有重要临床应用价值，但存在几何构型和力学性能与缺损区域匹配不良，而且力学支撑性能和降解速率在体内外难以调控和平衡等亟待解决的难题。本项目在前期运用3D打印构建多孔Fe-Mn金属材料基础上，研究Mn含量与力学性能的对应关系，建立孔隙特征与力学性能的本构方程，快速构建与骨缺损区域相适应的可控几何构型和定量可控力学性能的多孔Fe-Mn金属骨支架材料。通过分析Mn含量和孔隙特征对其降解速率的联合定量调控机制，以及降解速率和细胞毒性的量效关系，研究材料在体内促进骨重建过程的降解速率与力学支撑性能平衡关系。项目预期将实现3D打印多孔可生物降解Fe-Mn金属材料的个性化几何构型和定量可控力学性能，平衡支撑和降解的矛盾，揭示多孔可生物降解金属材料促进骨缺损修复重建的生物力学原理，为实现骨缺损区域骨再生提供新思路、新方法和理论依据。

骨缺损是临床常见病症，新型多孔可生物降解Fe基金属材料对于负重区骨缺损重建具有重要临床应用价值，但存在几何构型和力学性能与缺损区域匹配不良，而且力学支撑性能和降解速率在体内外难以调控和平衡等亟待解决的难题。本项目在前期运用3D打印构建多孔Fe-Mn金属材料基础上，研究Mn含量与力学性能的对应关系，建立孔隙特征与力学性能的本构方程，快速构建与骨缺损区域相适应的可控几何构型和定量可控力学性能的多孔Fe-Mn金属骨支架材料。通过分析Mn含量和孔隙特征对其降解速率的联合定量调控机制，以及降解速率和细胞毒性的量效关系，研究材料在体内促进骨重建过程的降解速率与力学支撑性能平衡关系。本研究首次通过先进的激光选区熔化成形技术，制备出四组孔隙率（37.89-47.17%）、孔隙结构（孔径400μm，连接杆300-600μm）、力学性能（弹性模量 10.04-14.88GPa，屈服强度135.70-243.26MPa）、降解速率定量可调的3D打印多孔可生物降解Fe-30Mn金属骨支架材料。通过材料表征理化特性研究、体外体内研究，证实了该四组3D打印多孔可生物降解Fe-30Mn金属骨支架材料具有优异的力学性能、适中的降解速率和良好的体外、体内生物相容性，可有效修复负重区域骨缺损，并在骨缺损修复过程中为局部提供良好的力学支撑。其中，孔隙率最高的Fe-30Mn材料（47.17%孔隙率）具有更好的细胞粘附、增殖及骨长入性能，而且在负重区域骨缺损修复过程中既提供确切的支撑，又可稳定降解。此外，本研究制备的四组3D打印多孔可生物降解Fe-30Mn金属骨支架材料室温相均为顺磁性的奥氏体，可以满足MRI检查的要求。本项目实现了3D打印多孔可生物降解Fe-Mn金属材料的个性化几何构型和力学性能定量可控，揭示了多孔Fe-30Mn可生物降解金属材料促进骨缺损修复重建的生物力学原理，为实现负重区域骨缺损区域骨再生和研发新一代的可降解金属骨修复材料提供了新思路、新方法和理论依据。