Molecular structure of human bones successfully modeled

MIT News : Bone is made from a combination of collagenâmdash;a soft, flexible biomoleculeâmdash;and hydroxyapatiteâmdash;a hard, brittle mineral. How the two materials combine to form something that is hard and tough yet still slightly flexible has been hard to determine because the structure can only be imaged in two dimensionsâmdash;either surface images or cross-sectional slices. And computers have only recently reached the point that they can create models of the structure in reasonable timeframes. Markus Buehler of MIT and his colleagues have now taken advantage of the new generation of supercomputers to iterate through models created from 2D scans and measurements of structural stresses. The result is the first successful model of the molecular structure of human bone. The model reveals that hydroxyapatite grains are embedded in a matrix of collagen. The mineral absorbs many of the forces applied to the structure, while stretching forces are absorbed by the collagen. Having a clear picture of bone’s structure may help researchers to better understand bone diseases, such as osteoporosis, and to develop bone-like materials for biomedicine or even structural engineering.