The Vital Role of Carbohydrate Molecules in Bone Strength
Bone comprises organic and inorganic components in a complex composite which confers remarkable ability to withstand mechanical loading, adapt to the environment, and act as a mineral reservoir.1 Toughness and stiffness are supplied by the organic and mineral phases, respectively. The former is a matrix of proteins, mainly collagen, and other macromolecules including proteoglycans (PGs) rich in acidic glycosaminoglycans (GAGs). The latter is a hydroxylated calcium phosphate resembling the mineral hydroxyapatite. Although the relationship between the two phases must be crucial to the properties of bone in health and disease, little is known about the macromolecules which constitute and stabilize the boundary. The molecular interaction between these components is fundamental for strength, adaptation, and growth and will be key to new understanding of bone health problems; current literature is dominated by an assumption that it is proteins which stabilize the interface.2,3 However, in this communication we present a direct demonstration using solid-state NMR (SSNMR) that normal bone mineral contacts its organic matrix via polysaccharides, most likely GAGs in PGs.
Erica R. Wise, Sergey Maltsev, M. Elisabeth Davies, Melinda J. Duer, Christian Jaeger, Nigel Loveridge, Rachel C. Murray, and David G. Reid. The Organic−Mineral Interface in Bone Is Predominantly Polysaccharide. Chem. Mater 2007 September Department of Chemistry, University of Cambridge