The load-bearing function of the skeleton depends on bone geometry and tissue material properties. The effect of geometry is well-understood from the principles of solid mechanics. Structural analyses generally assume that the tissue material properties are homogenous and time-invariant. However, healthy bone tissue is a heterogeneous material whose properties vary spatially and temporally within skeletal structures. Furthermore, diseases such as osteoporosis affect not only bone quantity but also tissue quality and may alter material heterogeneity. Therefore, the contribution of tissue composition to bone mechanical properties needs to be demonstrated to understand the impact of disease and determine effective treatments.
From a materials science perspective, tissue composition and microstructure determine material mechanical properties. Therefore, the mineral and matrix properties are critical in bone, as are microstructural features such as lamellae. Understanding the contribution of these features to the mechanical behavior of bone tissue requires combining analyses of composition with submicron-scale mechanical properties, an approach not previously applied to this tissue. Ideally, we would like to translate composition and structure directly to tissue function across multiple length scales. However, very little is known of the mechanical behavior at the constituent tissue level, within lamellae and trabecular. Therefore, we have been working to correlate microscale compositional and structural measurements with tissue mechanical properties, focusing on the role of mineral.
CURRENT PROJECTS
• FT-IR microscopy of mineral structure in osteoporosis
PAST PROJECTS
• Role of microstructure in nanomechanical behavior of bone tissue
• Multi-keV x-ray microscopy facility for bio-imaging
• Core Center for Musculoskeletal Repair and Regeneration (at HSS)
