1. Intermolecular channels direct crystal orientation in mineralized collagen
- Author
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E. Deniz Eren, Heiner Friedrich, Anat Akiva, Christian Ottmann, Nico A. J. M. Sommerdijk, Maarten J. M. Wirix, Wim Bras, Fabio Nudelman, Yifei Xu, Joseph P. R. O. Orgel, Bram Cantaert, Giuseppe Portale, Paul H. H. Bomans, Fiona C. Meldrum, Daniel Hermida-Merino, Wouter H. Nijhuis, Macromolecular Chemistry & New Polymeric Materials, Materials and Interface Chemistry, Chemical Biology, Physical Chemistry, EIRES Systems for Sustainable Heat, ICMS Core, and EAISI Foundational
- Subjects
Biomineralization ,Models, Molecular ,General Physics and Astronomy ,02 engineering and technology ,Matrix (biology) ,01 natural sciences ,Mineralization (biology) ,Bone and Bones/chemistry ,law.invention ,X-Ray Diffraction ,law ,Models ,Spatial ,Crystallization ,lcsh:Science ,Child ,Tomography ,Minerals ,Multidisciplinary ,Intermolecular force ,021001 nanoscience & nanotechnology ,Tissues ,Reconstructive and regenerative medicine Radboud Institute for Molecular Life Sciences [Radboudumc 10] ,X-ray crystallography ,Female ,Collagen ,0210 nano-technology ,Collagen/chemistry ,Materials science ,Science ,Crystal orientation ,Electrons ,010402 general chemistry ,Fibril ,Article ,Bone and Bones ,General Biochemistry, Genetics and Molecular Biology ,Biomaterials ,All institutes and research themes of the Radboud University Medical Center ,stomatognathic system ,Orientation ,Humans ,Minerals/chemistry ,Orientation, Spatial ,Durapatite/chemistry ,Molecular ,General Chemistry ,0104 chemical sciences ,Durapatite ,Biophysics ,lcsh:Q ,Electron microscope ,Nanomedicine Radboud Institute for Molecular Life Sciences [Radboudumc 19] - Abstract
The mineralized collagen fibril is the basic building block of bone, and is commonly pictured as a parallel array of ultrathin carbonated hydroxyapatite (HAp) platelets distributed throughout the collagen. This orientation is often attributed to an epitaxial relationship between the HAp and collagen molecules inside 2D voids within the fibril. Although recent studies have questioned this model, the structural relationship between the collagen matrix and HAp, and the mechanisms by which collagen directs mineralization remain unclear. Here, we use XRD to reveal that the voids in the collagen are in fact cylindrical pores with diameters of ~2 nm, while electron microscopy shows that the HAp crystals in bone are only uniaxially oriented with respect to the collagen. From in vitro mineralization studies with HAp, CaCO3 and γ-FeOOH we conclude that confinement within these pores, together with the anisotropic growth of HAp, dictates the orientation of HAp crystals within the collagen fibril., Mineralized collagen is the building block of bone but how the collagen directs hydroxyapatite formation remains unclear. Here, the authors demonstrate cylindrical pores in collagen and how the anisotropic growth of hydroxyapatite directs the orientation of crystal growth in mineralized collagen.
- Published
- 2020