废用引起的皮质骨微纳尺度结构变化和组织粘弹性相关关系研究

废用会造成人体骨骼所受机械应力缺失，废用导致的骨质疏松不但临床发生率高，而且是宇航员长期太空飞行的主要障碍。开展废用性骨质疏松研究对于患者的临床干预和航天员的身体防护具有重要意义。近年的研究发现，缺乏应力刺激对皮质骨的影响比松质骨更大，皮质骨在骨折风险预测中起着更重要的作用，无论如何，人们对废用期皮质骨微纳结构和组织力学特性的变化规律还知之甚少,废用引起的微纳结构变化与皮质骨粘弹性之间的关系也不清晰。基于此，本课题采用μ-CT、Nano-CT等多种微纳尺度观测技术和超声共振谱细观力学参数测量方法，结合废用性骨质疏松动物模型,开展不同废用阶段皮质骨微结构、超微结构与力学参数测量研究，系统揭示废用过程中组织微纳结构与细观力学特性的变化规律，阐明皮质骨结构变化对于组织粘弹性的影响，建立相关关系。项目预期结果对于深入理解废用性骨质疏松的发生过程与机制、制定骨评价标准和骨折风险预测指标都有重要意义。

The disuse will cause the lack of stimulation of the mechanical stress on the human bones. Osteoporosis caused by disuse not only has a high clinical incidence, but also is a major obstacle for astronauts' long-term space flight. The study on disused osteoporosis has an important significance to clinical intervention for the patients and to physical protection for the astronauts. Recent studies have found that lack of stress stimulation has a greater impact on cortical bone than cancellous bone, and cortical bone plays a more important role in the prediction of fracture risk. However, up to now, limited knowledge was mastered about how micro/nano structure and mechanical properties of cortical bone changed during disuse, and what quantitative relationship existed between micro/nano structure and viscoelasticity of cortical bone. Based on this, this project is planned to find the change pattern between microstructure and mesoscopic mechanical properties of cortical bone and clarify the effect of cortical bone structure changes on tissue viscoelasticity in disuse, by using μ-CT, nano CT and other technics to observe the structure of cortical bone in micro/nano scale and resonant ultrasound spectroscopy (RUS) to measure the mechanical properties in mesoscopic scale respectively. This study try to reveal the changes of tissue micro/nano structure and meso-mechanical properties during the disuse, to clarify the effect of cortical bone structure changes on tissue viscoelasticity and to establish the relationship between the micro/nano structure and tissue viscoelasticity systematically. The expected results of the study are of great significance for in-depth understanding of the occurrence mechanism, and help for developing bone evaluation standards and fracture risk prediction indicators.