骨微纳米力学性能及韧化机理研究

项目名称： 骨微纳米力学性能及韧化机理研究

项目编号： No.31500762

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 生物科学

项目作者： 杭飞

作者单位： 华南理工大学

项目金额： 17万元

中文摘要： 骨骼是人体重要器官，具有优良的力学性能。骨纳米力学的研究，有利于揭示骨病影响骨力学的基本机理，对研发新型仿生骨修复材料具有指导意义。不同于传统采用纳米压痕原理的原位力学测试方法，本项目利用MEMS对微纳米尺度骨材料样品进行直接机械测试，结果更准确，应力状态更接近骨骼真实受力情况。同时，具有原子分辨率的AFM原位记录骨基本结构单元MCFs内三螺旋多肽链和HA晶体的行为特征，从而揭示MCFs形变、失效和断裂的分子行为机理。通过匹配骨样品的应力应变情况，可进一步研究MCFs在骨形变中的影响和对骨宏观力学性能的贡献。研究还将验证项目组提出的，MCFs间游离Ca2+离子通过调控骨形变中MCFs的滑移行为，从而影响骨断裂韧性的假设。通过此项目，将有望更深入的理解MCFs影响骨整体力学性能，尤其是断裂韧性的基本机理。

中文关键词： 骨生物力学；微纳米结构；多尺度；骨质疏松；矿化胶原蛋白微纤维

英文摘要： Bone, as an important organ in human body, has been optimized through out it’s relatively complex hierarchical structure to adapt it’s mechanical function at all levels. Via investigating MCFs mechanically, which is the most basic structural unit of bone, an improved understanding on mechanisms of bone diseases’ effect on mechanical behaviors is promoted. Biomimetic bone design and engineering composite with high mechanical performance could also been inspired upon the fundamental understanding of nanomechanics of bone. In this proposed project, a novel in-situ nano mechanical testing method will be developed by combining MEMS and AFM effectively. MCFs will be mechanically evaluated through tensile testing bone tissue from different sources using MEMS at micro scale. Meanwhile, the morphology of MCFs is will be recorded by AFM with atomic resolution. The tropocollagen molecular with HA will be monitored during MCFs deformation at nano scale. The mechanical contribution especially the toughening effects from MCFs to the whole bone will be studied. By comparing mechanical behaviors of MCFs from different sources including different species and health conditions, the influence of distribution of HA on mechanical properties and toughening mechanisms will be reveled. A hypnosis of ionic sacrificial bonding between MCFs is proposed in which the Ca2+ ions have influence on slippery behavior of MCFs in bone deformation leading to different toughening results by altering Ca2+ concentrations. A deeper understanding of MCFs’s influence on mechanical properties of bone, especially the toughening mechanisms is expected to achieve.

英文关键词： Bone biomechanics;Micro-nano structure;Hierarchy ;Osteoporosis;Mineralized collagen fibril