title: Mechanical and mineral properties of osteogenesis imperfecta human bones at the tissue level.
abstract: Osteogenesis imperfecta (OI) is a genetic disorder characterized by an increase in bone fragility on the macroscopic scale, but few data are available to describe the mechanisms involved on the tissue scale and the possible correlations between these scales. To better understand the effects of OI on the properties of human bone, we studied the mechanical and chemical properties of eight bone samples from children suffering from OI and compared them to the properties of three controls. High-resolution computed tomography, nanoindentation and Raman microspectroscopy were used to assess those properties. A higher tissue mineral density was found for OI bone (1.131 gHA/cm3 vs. 1.032 gHA/cm3, p=0.032), along with a lower Young's modulus (17.6 GPa vs. 20.5 GPa, p=0.024). Obviously, the mutation-induced collagen defects alter the collagen matrix, thereby affecting the mineralization. Raman spectroscopy showed that the mineral-to-matrix ratio was higher in the OI samples, while the crystallinity was lower, suggesting that the mineral crystals were smaller but more abundant in the case of OI. This change in crystal size, distribution and composition contributes to the observed decrease in mechanical strength.
authors.affiliation: LTDS UMR CNRS 5513, Ecole Centrale Lyon, 36 avenue Guy de Collongue, 69134 Ecully, France.
authors.forename: Laurianne
authors.initials: L
authors.lastname: Imbert
authors.affiliation: Department of Pediatric Orthopedics, Necker - Enfants Malades Hospital, AP-HP, Paris Descartes University, 145 rue de Sèvres, 75014 Paris, France; B2OA UMR CNRS 7052, University Paris-Diderot, 10 avenue de Verdun, 75010 Paris, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Aurégan
authors.affiliation: LTDS UMR CNRS 5513, Ecole Centrale Lyon, 36 avenue Guy de Collongue, 69134 Ecully, France.
authors.forename: Kélig
authors.initials: K
authors.lastname: Pernelle
authors.affiliation: LTDS UMR CNRS 5513, Ecole Centrale Lyon, 36 avenue Guy de Collongue, 69134 Ecully, France. Electronic address: thierry.hoc@ec-lyon.fr.
authors.forename: Thierry
authors.initials: T
authors.lastname: Hoc
mesh_terms: D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism* / Q000503:physiopathology; D002648:Child; D006801:Humans; D010013:Osteogenesis Imperfecta / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D013059:Spectrum Analysis, Raman; D014057:Tomography, X-Ray Computed
keywords: Mineralization; Nanoindentation; Osteogenesis imperfecta; Raman microspectroscopy; Tissue properties