The research objective of this award is to provide a mechanistic explanation on the relationship between the ultrastructural (i.e. mineral and collagen) and bulk (tissue level) mechanical behavior of bone and to elucidate the ultrastructural origins of bone fragility fractures. To do so, a novel synchrotron X-ray diffraction based approach will be developed to fully capture the in situ behavior (e.g. strain tensors, residual strain status, damage accumulation, and viscous response) of mineral crystals and collagen fibrils in bone under load. Since the in situ behavior will be obtained simultaneously with measurements of bulk properties of bone, the relationship between the nanomechanics and bulk behavior of bone can be readily established under different loading conditions. Studies under this award will apply X-ray diffraction, crystal physics and biomechanics tools to distinguish the in situ behavior of individual group of crystals and collagen fibrils and its correlation with the bulk behavior of bone samples.
If successful, this study would enable us to identify the ultrastructural origins that dominate the bulk deformation/failure processes of bone. This will provide a rigorous foundation for accurate prediction of bone behaviors at ultrastructural levels and benefit for multiscale modeling of the tissue. The methodologies of this study may be readily extended to studying pathological changes of bone in animal models, thus providing a unique opportunity to study the interplay between bone biology and biomechanics in different bone disorders. This in turn may help develop the therapeutic regimens that specifically target the ultrastructural causes of bone fragility fractures. The educational plan is focused on student raining at graduate, undergraduate, and high school levels, course development in Skeletal Tissue Mechanics and Advanced Biomechanics, and recruitment of underrepresented students to participate in interdisciplinary research programs in cooperation with the Research Center for Minority Institutions at UTSA.
