title: Small-Angle X-ray Scattering Demonstrates Similar Nanostructure in Cortical Bone from Young Adult Animals of Different Species.
abstract: Despite the vast amount of studies focusing on bone nanostructure that have been performed for several decades, doubts regarding the detailed structure of the constituting hydroxyapatite crystal still exist. Different experimental techniques report somewhat different sizes and locations, possibly due to different requirements for the sample preparation. In this study, small- and wide-angle X-ray scattering is used to investigate the nanostructure of femur samples from young adult ovine, bovine, porcine, and murine cortical bone, including three different orthogonal directions relative to the long axis of the bone. The radially averaged scattering from all samples reveals a remarkable similarity in the entire q range, which indicates that the nanostructure is essentially the same in all species. Small differences in the data from different directions confirm that the crystals are elongated in the [001] direction and that this direction is parallel to the long axis of the bone. A model consisting of thin plates is successfully employed to describe the scattering and extract the plate thicknesses, which are found to be in the range of 20-40 Å for most samples but 40-60 Å for the cow samples. It is demonstrated that the mineral plates have a large degree of polydispersity in plate thickness. Additionally, and equally importantly, the scattering data and the model are critically evaluated in terms of model uncertainties and overall information content.
authors.affiliation: Department of Biomedical Engineering, Lund University, 221 00, Lund, Sweden.
authors.forename: Jørn Døvling
authors.initials: JD
authors.lastname: Kaspersen
authors.affiliation: Department of Biomedical Engineering, Lund University, 221 00, Lund, Sweden.|Department of Applied Physics, University of Eastern Finland, 70 211, Kuopio, Finland.
authors.forename: Mikael Juhani
authors.initials: MJ
authors.lastname: Turunen
authors.affiliation: Department of Biomedical Engineering, Lund University, 221 00, Lund, Sweden.
authors.forename: Neashan
authors.initials: N
authors.lastname: Mathavan
authors.affiliation: Max IV Laboratory, Lund University, 221 00, Lund, Sweden.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lages
authors.affiliation: Interdisciplinary Nanoscience Center and Department of Chemistry, Aarhus University, Aarhus, Denmark.
authors.forename: Jan Skov
authors.initials: JS
authors.lastname: Pedersen
authors.affiliation: Division of Physical Chemistry, Lund University, Box 124, 221 00, Lund, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Olsson
authors.affiliation: Department of Biomedical Engineering, Lund University, 221 00, Lund, Sweden. hanna.isaksson@bme.lth.se.
authors.forename: Hanna
authors.initials: H
authors.lastname: Isaksson
mesh_terms: D000375:Aging; D000818:Animals; D002113:Calcification, Physiologic / Q000502:physiology*; D002417:Cattle; D000071538:Cortical Bone / Q000648:ultrastructure*; D005269:Femur / Q000473:pathology; D012542:Scattering, Radiation; D012756:Sheep; D013552:Swine; D014961:X-Ray Diffraction / Q000379:methods
keywords: Bone; Mineral thickness; Nanostructure; Small-angle X-ray scattering; Wide-angle X-ray scattering