Forming Bones and Teeth

They used the world's most modern electron microscope to capture a three-dimensional image of the nanoparticles that form the basis for this process. The results provide a greater understanding of the formation of bones and teeth. This creates a prospect of better materials and processes for industry, based on nature.

The researchers, led by Dr Nico Sommerdijk, managed to image small clusters, with a diameter of 0.7 nanometers, in a solution of calcium carbonate. They showed that these clusters, containing no more than about ten ions, were the start of the growth process from which the crystalline biomineral is ultimately formed.

To do this, they used the extremely high resolution of a special electron microscope. It allowed them to see how the clusters nucleated into larger, unstructured nanoparticles with an average diameter of about 30 nanometers.

Three-dimensional imaging revealed that an organic surface introduced by the researchers allowed these nanoparticles to grow into larger particles, in which crystalline areas could be formed later, through structuring of the ions. The researchers demonstrated a second role for the organic layer: it directed quite precisely the direction in which the mineral could grow into a mature biomineral. In the near future they hope to show that the mechanism they have discovered also applies to the formation of other crystalline biominerals, and perhaps even to other inorganic materials.

This is important for research into the growth of bones and substitute bone material. The work might also be used in nanotechnology, to direct the growth of nanoparticles in the same way as appears to happen in nature: through a subtle interplay of organic and inorganic materials.; Source: Netherlands Organization for Scientific Research