Understanding the role of cement lines for human bone mineralization via XRF/ SAXS and Texture tomography

Bone is essential for human health and wellbeing due to its central role in the musculoskeletal system. Bone is continually remodeled to maintain bone performance. At the border between old and new bone, cement lines occur. Cement lines are only a few microns across and their composition differs from that of the surrounding bone. However, their structure remains unknown. This information is important for understanding both bone mechanical properties and the signals that govern the behavior of bone cells involved in bone remodeling. Since bone is a 3D composite, the structure must be mapped in 3D. This has recently become possibly by new techniques developed by the proposers. We thus propose to conduct combined SAXS tensor and texture tomography to map the orientation distributions of, respectively, nanostructural features and the bone biomineral nanocrystals. This will enable forming a structural model of cement lines for the first time.

骨骼作为肌肉骨骼系统的核心组成部分，对人类健康与福祉至关重要。骨骼会持续进行重塑以维持其生理功能。在新旧骨组织的交界处，会形成骨界线（cement lines）。骨界线的宽度仅为数微米，其组成成分与周围骨组织存在差异。然而，其微观结构至今仍未明确。该信息对于解析骨骼的力学特性，以及调控骨重塑过程中骨细胞行为的信号通路均具有重要意义。由于骨骼属于三维复合材料，因此需通过三维成像技术对其结构进行测绘。近期，本项目提案者所开发的新型技术已使该三维测绘成为可能。因此，我们计划联合应用小角X射线散射（SAXS）张量成像与纹理断层扫描技术，分别测绘纳米结构特征与骨生物矿化纳米晶体的取向分布。这将首次实现骨界线的结构建模。