Bone mineralization: Water brings order

Nadine Nassif, Thierry Azaïs and colleagues report that the interactions of water with mineral surfaces induce by themselves highly organized bone nanostructures. Nassif and collaborators show that the mineral nanoparticles in biomimetic apatite models and in intact bone samples have an intrinsic ability to organize themselves parallel to one another when a layer of water is bound to their surface even in the absence of organic molecules. They also demonstrate that such surface-bound water is maintained only in the presence of the highly hydrated amorphous coating of the mineral particles; without it, the particles are arranged randomly. Furthermore, Nassif and co-authors' work suggests that, structurally, the mineral nanoparticles in bone are ceramic plates glued to each other along an organic substrate by the capillary action of a thin layer of water. Nassif and colleagues' data also help to reconcile several questions on biomineralization.