title: Microfibril orientation dominates the microelastic properties of human bone tissue at the lamellar length scale.
abstract: The elastic properties of bone tissue determine the biomechanical behavior of bone at the organ level. It is now widely accepted that the nanoscale structure of bone plays an important role to determine the elastic properties at the tissue level. Hence, in addition to the mineral density, the structure and organization of the mineral nanoparticles and of the collagen microfibrils appear as potential key factors governing the elasticity. Many studies exist on the role of the organization of collagen microfibril and mineral nanocrystals in strongly remodeled bone. However, there is no direct experimental proof to support the theoretical calculations. Here, we provide such evidence through a novel approach combining several high resolution imaging techniques: scanning acoustic microscopy, quantitative scanning small-Angle X-ray scattering imaging and synchrotron radiation computed microtomography. We find that the periodic modulations of elasticity across osteonal bone are essentially determined by the orientation of the mineral nanoparticles and to a lesser extent only by the particle size and density. Based on the strong correlation between the orientation of the mineral nanoparticles and the collagen molecules, we conclude that the microfibril orientation is the main determinant of the observed undulations of microelastic properties in regions of constant mineralization in osteonal lamellar bone. This multimodal approach could be applied to a much broader range of fibrous biological materials for the purpose of biomimetic technologies.
authors.affiliation: UMPC Univ Paris 6, UMR 7623, Laboratoire d'Imagerie Paramétrique, Paris, France. mathilde.granke@gmail.com
authors.forename: Mathilde
authors.initials: M
authors.lastname: Granke
authors.forename: Aurélien
authors.initials: A
authors.lastname: Gourrier
authors.forename: Fabienne
authors.initials: F
authors.lastname: Rupin
authors.forename: Kay
authors.initials: K
authors.lastname: Raum
authors.forename: Françoise
authors.initials: F
authors.lastname: Peyrin
authors.forename: Manfred
authors.initials: M
authors.lastname: Burghammer
authors.forename: Amena
authors.initials: A
authors.lastname: Saïed
authors.forename: Pascal
authors.initials: P
authors.lastname: Laugier
mesh_terms: D000369:Aged, 80 and over; D000465:Algorithms; D001696:Biomechanical Phenomena; D032701:Biomimetics; D015519:Bone Density; D016723:Bone Remodeling; D001842:Bone and Bones / Q000473:pathology*; D002102:Cadaver; D003094:Collagen / Q000737:chemistry; D004548:Elasticity; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020894:Microfibrils / Q000737:chemistry; D015233:Models, Statistical; D053758:Nanoparticles / Q000737:chemistry; D010316:Particle Size; D013499:Surface Properties; D017356:Synchrotrons; D055114:X-Ray Microtomography
chemical_list: D003094:Collagen