Three-dimensional investigation of the relationship between orientation and microelastic properties of mineralized collagen fibrils in human osteonal bone

Chemical composition and fibrillar organization are major determinants of osteonal bone tissue mechanics. However, prominent methodologies commonly applied to investigate mechanical properties of bone on the micro scale are usually not able to concurrently describe both factors. In this study, we used synchrotron X-ray phase nano-tomography, polarized Raman spectroscopy and scanning acoustic microscopy to analyse not only the orientation of the mineralized collagen fibrils in three dimensions, but also the chemical composition and the elastic properties in site-matched regions of human osteonal bone in situ with sub-micron resolution. The aim of this study was to compare the fibrillar orientation patterns identified with the different methodologies and to determine the impact of compositional and organizational characteristics on local elastic properties to gain further insight into the structure-functional relationship of osteonal bone.