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de la Isla A, Brostow W, Bujard B, Estevez M, Rodriguez JR, Vargas S, Castaño VM. Nanohybrid scratch resistant coatings for teeth and bone viscoelasticity manifested in tribology. ACTA ACUST UNITED AC 2016. [DOI: 10.1080/14328917.2003.11784770] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Agustín de la Isla
- Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science & Engineering, University of North Texas, PO Box 305310, Denton, TX 76203-5310, USA,
- Doctorado en Ciencia e Ingenieria de Materiales, Universidad Autonoma del Estado de Morelos, Cuernavaca, Morelos, Mexico
- Licenciatura en Odontologia, Facultad de Medicina, Universidad Autonoma de Queretaro, Clavel 200 Prados de la Capilla, Queretaro, Qro., Mexico
| | - Witold Brostow
- Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science & Engineering, University of North Texas, PO Box 305310, Denton, TX 76203-5310, USA,
- Centro de Fisica Aplicada y Tecnologia Avanzada (CFATA), Universidad Nacional Autonoma de México, Apartado Postal 1–1010, Queretaro, Qro. 76000, Mexico
| | - Bernard Bujard
- Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science & Engineering, University of North Texas, PO Box 305310, Denton, TX 76203-5310, USA,
| | - Miriam Estevez
- Centro de Fisica Aplicada y Tecnologia Avanzada (CFATA), Universidad Nacional Autonoma de México, Apartado Postal 1–1010, Queretaro, Qro. 76000, Mexico
| | - J. Rogelio Rodriguez
- Centro de Fisica Aplicada y Tecnologia Avanzada (CFATA), Universidad Nacional Autonoma de México, Apartado Postal 1–1010, Queretaro, Qro. 76000, Mexico
| | - Susana Vargas
- Centro de Fisica Aplicada y Tecnologia Avanzada (CFATA), Universidad Nacional Autonoma de México, Apartado Postal 1–1010, Queretaro, Qro. 76000, Mexico
| | - Victor M. Castaño
- Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science & Engineering, University of North Texas, PO Box 305310, Denton, TX 76203-5310, USA,
- Centro de Fisica Aplicada y Tecnologia Avanzada (CFATA), Universidad Nacional Autonoma de México, Apartado Postal 1–1010, Queretaro, Qro. 76000, Mexico
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Brostow W, Jaklewicz M, Mehta S, Montemartini P. Effects of magnetic fields on flexural properties of a longitudinal polymer liquid crystal. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s10019-002-0163-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Witold Brostow
- Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science, University of North Texas, Denton, TX 76203-5310, USATel.: , Fax:
| | - Magdalena Jaklewicz
- Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science, University of North Texas, Denton, TX 76203-5310, USATel.: , Fax:
- Department of Mechanical and Biomechanical Engineering, Cracow University of Technology, Warszawska 24, 31-155 Cracow, Poland
| | - Shreefal Mehta
- Southwestern Medical Center, University of Texas at Dallas, 5323 Harry Hines Blvd., Dallas, TX 75235; now at Lally School of Management and Technology, Rensselaer Polytechnic Institute, 110 8th St., Troy, NY 12180-3590, USA
| | - Pablo Montemartini
- Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of Materials Science, University of North Texas, Denton, TX 76203-5310, USATel.: , Fax:
- Currently at Consejo Nacional de Investigaciones Cientificas y Técnicas (CONICET)—Universidad Nacional de Mar del Plata, J.B. Justo 4302, 7600 Mar del Plata, Argentina
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3
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Rodriguez-Florez N, Garcia-Tunon E, Mukadam Q, Saiz E, Oldknow KJ, Farquharson C, Millán JL, Boyde A, Shefelbine SJ. An investigation of the mineral in ductile and brittle cortical mouse bone. J Bone Miner Res 2015; 30:786-95. [PMID: 25418329 PMCID: PMC4507744 DOI: 10.1002/jbmr.2414] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 11/07/2014] [Accepted: 11/20/2014] [Indexed: 12/28/2022]
Abstract
Bone is a strong and tough material composed of apatite mineral, organic matter, and water. Changes in composition and organization of these building blocks affect bone's mechanical integrity. Skeletal disorders often affect bone's mineral phase, either by variations in the collagen or directly altering mineralization. The aim of the current study was to explore the differences in the mineral of brittle and ductile cortical bone at the mineral (nm) and tissue (µm) levels using two mouse phenotypes. Osteogenesis imperfecta model, oim(-/-) , mice have a defect in the collagen, which leads to brittle bone; PHOSPHO1 mutants, Phospho1(-/-) , have ductile bone resulting from altered mineralization. Oim(-/-) and Phospho1(-/-) were compared with their respective wild-type controls. Femora were defatted and ground to powder to measure average mineral crystal size using X-ray diffraction (XRD) and to monitor the bulk mineral to matrix ratio via thermogravimetric analysis (TGA). XRD scans were run after TGA for phase identification to assess the fractions of hydroxyapatite and β-tricalcium phosphate. Tibiae were embedded to measure elastic properties with nanoindentation and the extent of mineralization with backscattered electron microscopy (BSE SEM). Results revealed that although both pathology models had extremely different whole-bone mechanics, they both had smaller apatite crystals, lower bulk mineral to matrix ratio, and showed more thermal conversion to β-tricalcium phosphate than their wild types, indicating deviations from stoichiometric hydroxyapatite in the original mineral. In contrast, the degree of mineralization of bone matrix was different for each strain: brittle oim(-/-) were hypermineralized, whereas ductile Phospho1(-/-) were hypomineralized. Despite differences in the mineralization, nanoscale alterations in the mineral were associated with reduced tissue elastic moduli in both pathologies. Results indicated that alterations from normal crystal size, composition, and structure are correlated with reduced mechanical integrity of bone.
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Bart ZR, Hammond MA, Wallace JM. Multi-scale analysis of bone chemistry, morphology and mechanics in the oim model of osteogenesis imperfecta. Connect Tissue Res 2014; 55 Suppl 1:4-8. [PMID: 25158170 DOI: 10.3109/03008207.2014.923860] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Osteogenesis imperfecta is a congenital disease commonly characterized by brittle bones and caused by mutations in the genes encoding Type I collagen, the single most abundant protein produced by the body. The oim model has a natural collagen mutation, converting its heterotrimeric structure (two α1 and one α2 chains) into α1 homotrimers. This mutation in collagen may impact formation of the mineral, creating a brittle bone phenotype in animals. Femurs from male wild type (WT) and homozygous (oim/oim) mice, all at 12 weeks of age, were assessed using assays at multiple length scales with minimal sample processing to ensure a near-physiological state. Atomic force microscopy (AFM) demonstrated detectable differences in the organization of collagen at the nanoscale that may partially contribute to alterations in material and structural behavior obtained through mechanical testing and reference point indentation (RPI). Changes in geometric and chemical structure obtained from µ-Computed Tomography and Raman spectroscopy indicate a smaller bone with reduced trabecular architecture and altered chemical composition. Decreased tissue material properties in oim/oim mice are likely driven by changes in collagen fibril structure, decreasing space available for mineral nucleation and growth, as supported by a reduction in mineral crystallinity. Multi-scale analyses of this nature offer much in assessing how molecular changes compound to create a degraded, brittle bone phenotype.
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Affiliation(s)
- Zachary R Bart
- Department of Biomedical Engineering, Indiana University-Purdue University , Indianapolis, IN , USA
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5
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Carriero A, Zimmermann EA, Paluszny A, Tang SY, Bale H, Busse B, Alliston T, Kazakia G, Ritchie RO, Shefelbine SJ. How tough is brittle bone? Investigating osteogenesis imperfecta in mouse bone. J Bone Miner Res 2014; 29:1392-1401. [PMID: 24420672 PMCID: PMC4477967 DOI: 10.1002/jbmr.2172] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/18/2013] [Accepted: 01/09/2014] [Indexed: 12/12/2022]
Abstract
The multiscale hierarchical structure of bone is naturally optimized to resist fractures. In osteogenesis imperfecta, or brittle bone disease, genetic mutations affect the quality and/or quantity of collagen, dramatically increasing bone fracture risk. Here we reveal how the collagen defect results in bone fragility in a mouse model of osteogenesis imperfecta (oim), which has homotrimeric α1(I) collagen. At the molecular level, we attribute the loss in toughness to a decrease in the stabilizing enzymatic cross-links and an increase in nonenzymatic cross-links, which may break prematurely, inhibiting plasticity. At the tissue level, high vascular canal density reduces the stable crack growth, and extensive woven bone limits the crack-deflection toughening during crack growth. This demonstrates how modifications at the bone molecular level have ramifications at larger length scales affecting the overall mechanical integrity of the bone; thus, treatment strategies have to address multiscale properties in order to regain bone toughness. In this regard, findings from the heterozygous oim bone, where defective as well as normal collagen are present, suggest that increasing the quantity of healthy collagen in these bones helps to recover toughness at the multiple length scales.
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Affiliation(s)
- A. Carriero
- Department of Bioengineering, Imperial College London, U.K
- Materials Sciences Division, Lawrence Berkeley National Laboratory, U.S.A
- Department of Materials Science and Engineering, University of California Berkeley, U.S.A
| | - E. A. Zimmermann
- Materials Sciences Division, Lawrence Berkeley National Laboratory, U.S.A
- Department of Materials Science and Engineering, University of California Berkeley, U.S.A
| | - A. Paluszny
- Department of Earth Science and Engineering, Imperial College London, U.K
| | - S. Y. Tang
- Department of Orthopaedic Surgery, University of California San Francisco, U.S.A
| | - H. Bale
- Materials Sciences Division, Lawrence Berkeley National Laboratory, U.S.A
- Department of Materials Science and Engineering, University of California Berkeley, U.S.A
| | - B. Busse
- Materials Sciences Division, Lawrence Berkeley National Laboratory, U.S.A
- Department of Materials Science and Engineering, University of California Berkeley, U.S.A
| | - T. Alliston
- Department of Orthopaedic Surgery, University of California San Francisco, U.S.A
| | - G. Kazakia
- Department of Radiology and Biomedical Imaging, University of California San Francisco, U.S.A
| | - R. O. Ritchie
- Materials Sciences Division, Lawrence Berkeley National Laboratory, U.S.A
- Department of Materials Science and Engineering, University of California Berkeley, U.S.A
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6
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Vanleene M, Porter A, Guillot PV, Boyde A, Oyen M, Shefelbine S. Ultra-structural defects cause low bone matrix stiffness despite high mineralization in osteogenesis imperfecta mice. Bone 2012; 50:1317-23. [PMID: 22449447 PMCID: PMC3407875 DOI: 10.1016/j.bone.2012.03.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 02/07/2012] [Accepted: 03/07/2012] [Indexed: 12/04/2022]
Abstract
Bone is a complex material with a hierarchical multi-scale organization from the molecule to the organ scale. The genetic bone disease, osteogenesis imperfecta, is primarily caused by mutations in the collagen type I genes, resulting in bone fragility. Because the basis of the disease is molecular with ramifications at the whole bone level, it provides a platform for investigating the relationship between structure, composition, and mechanics throughout the hierarchy. Prior studies have individually shown that OI leads to: 1. increased bone mineralization, 2. decreased elastic modulus, and 3. smaller apatite crystal size. However, these have not been studied together and the mechanism for how mineral structure influences tissue mechanics has not been identified. This lack of understanding inhibits the development of more accurate models and therapies. To address this research gap, we used a mouse model of the disease (oim) to measure these outcomes together in order to propose an underlying mechanism for the changes in properties. Our main finding was that despite increased mineralization, oim bones have lower stiffness that may result from the poorly organized mineral matrix with significantly smaller, highly packed and disoriented apatite crystals. Using a composite framework, we interpret the lower oim bone matrix elasticity observed as the result of a change in the aspect ratio of apatite crystals and a disruption of the crystal connectivity.
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Affiliation(s)
| | - Alexandra Porter
- Department of Materials, Imperial College London, London, SW7-2AZ, UK
| | - Pascale-Valerie Guillot
- Institute of Reproductive and Developmental Biology, Imperial College London, London, W12 0NN, UK
| | - Alan Boyde
- Dental Physical Sciences, Barts and The London School of Medicine and Dentistry, QMUL, London, E1 4NS, UK
| | - Michelle Oyen
- Department of Engineering, Cambridge University, Cambridge, CB2-1PZ, UK
| | - Sandra Shefelbine
- Department of Bioengineering, Imperial College London, London,SW7-2AZ, UK
- Corresponding author at: Department of Bioengineering, Imperial College London, Royal School of Mines Building, South Kensington Campus, London, SW7 2AZ, UK.
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Deuerling JM, Yue W, Espinoza Orías AA, Roeder RK. Specimen-specific multi-scale model for the anisotropic elastic constants of human cortical bone. J Biomech 2009; 42:2061-7. [PMID: 19664772 DOI: 10.1016/j.jbiomech.2009.06.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 05/29/2009] [Accepted: 06/02/2009] [Indexed: 11/30/2022]
Abstract
The anisotropic elastic constants of human cortical bone were predicted using a specimen-specific micromechanical model that accounted for structural parameters across multiple length scales. At the nano-scale, the elastic constants of the mineralized collagen fibril were estimated from measured volume fractions of the constituent phases, namely apatite crystals and Type I collagen. The elastic constants of the extracellular matrix (ECM) were predicted using the measured orientation distribution function (ODF) for the apatite crystals to average the contribution of misoriented mineralized collagen fibrils. Finally, the elastic constants of cortical bone tissue were determined by accounting for the measured volume fraction of Haversian porosity within the ECM. Model predictions using the measured apatite crystal ODF were not statistically different from experimental measurements for both the magnitude and anisotropy of elastic constants. In contrast, model predictions using common idealized assumptions of perfectly aligned or randomly oriented apatite crystals were significantly different from the experimental measurements. A sensitivity analysis indicated that the apatite crystal volume fraction and ODF were the most influential structural parameters affecting model predictions of the magnitude and anisotropy, respectively, of elastic constants.
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Affiliation(s)
- Justin M Deuerling
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, United States of America
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8
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Miller E, Delos D, Baldini T, Wright TM, Camacho NP. Abnormal mineral-matrix interactions are a significant contributor to fragility in oim/oim bone. Calcif Tissue Int 2007; 81:206-14. [PMID: 17660935 PMCID: PMC2945147 DOI: 10.1007/s00223-007-9045-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Accepted: 04/12/2007] [Indexed: 10/23/2022]
Abstract
The presence of abnormal type I collagen underlies the tissue fragility in the heritable disease osteogenesis imperfecta (OI), though the specific mechanism remains ill-defined. The current study addressed the question of how an abnormal collagen-based matrix contributes to reduced bone strength in OI by comparing the material properties of mineralized and demineralized bone from the oim/oim mouse, a model of OI that contains homotrimeric (alpha1(3)(I)) type I collagen, with the properties of bone from wildtype (+/+) mice. Femoral three-point bend tests combined with geometric analyses were conducted on intact (mineralized) 14-week-old oim/oim and +/+ mice. To investigate the bone matrix properties, tensile tests combined with geometric analyses were conducted on demineralized femora. The majority of the properties of the mineralized oim/oim bone were inferior to those of the +/+ bone, including greater brittleness (+78.6%) and lower toughness (-69.2%). In contrast, tensile measurements on the demineralized bone revealed no significant differences between the oim/oim and +/+ bone, indicating that the matrix itself was not brittle. These results support the concept that deficient material properties of the demineralized bone matrix itself are not the principal cause of the severe fragility in this model of OI. It is likely the abnormal collagen scaffold serves as a template for abnormal mineral deposition, resulting in an incompetent mineral-matrix interaction that contributes significantly to the inferior material properties of bone in oim/oim mice.
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Affiliation(s)
- Elizabeth Miller
- Musculoskeletal Integrity Program, Research Division, Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | - Demetris Delos
- Musculoskeletal Integrity Program, Research Division, Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | | | - Timothy M. Wright
- Musculoskeletal Integrity Program, Research Division, Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | - Nancy Pleshko Camacho
- Musculoskeletal Integrity Program, Research Division, Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
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9
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Chavassieux P, Seeman E, Delmas PD. Insights into material and structural basis of bone fragility from diseases associated with fractures: how determinants of the biomechanical properties of bone are compromised by disease. Endocr Rev 2007; 28:151-64. [PMID: 17200084 DOI: 10.1210/er.2006-0029] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Minimal trauma fractures in bone diseases are the result of bone fragility. Rather than considering bone fragility as being the result of a reduced amount of bone, we recognize that bone fragility is the result of changes in the material and structural properties of bone. A better understanding of the contribution of each component of the material composition and structure and how these interact to maintain whole bone strength is obtained by the study of metabolic bone diseases. Disorders of collagen (osteogenesis imperfecta and Paget's disease of bone), mineral content, composition and distribution (fluorosis and osteomalacia); diseases of high remodeling (postmenopausal osteoporosis, hyperparathyroidism, and hyperthyroidism) and low remodeling (osteopetrosis, pycnodysostosis); and other diseases (idiopathic male osteoporosis, corticosteroid-induced osteoporosis) produce abnormalities in the material composition and structure that lead to bone fragility. Observations in patients and in animal models provide insights on the biomechanical consequences of these illnesses and the nature of the qualities of bone that determine its strength.
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Affiliation(s)
- P Chavassieux
- Institut National de la Santé et de la Recherche Médicale Unit 831, Pavillon F, Hopital E. Herriot, 69437 Lyon Cedex 08, France
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Fan Z, Smith PA, Harris GF, Rauch F, Bajorunaite R. Comparison of nanoindentation measurements between osteogenesis imperfecta Type III and Type IV and between different anatomic locations (femur/tibia versus iliac crest). Connect Tissue Res 2007; 48:70-5. [PMID: 17453908 DOI: 10.1080/03008200601090949] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Nanoindentation was used to compare the intrinsic mechanical properties of bone tissue (iliac crest biopsy) from children with type III and type IV osteogenesis imperfecta (OI). Young's modulus and hardness values were not significantly different between the two clinical severity groups on either cortical or trabecular measurement. In comparing the ratio of modulus over hardness (E/H) between OI type III and IV. The type III bone showed a marginally significant decrease for cortical bone and significant decrease for trabecular bone, which indicated that the OI type III bone was more brittle than OI type IV bone at the tissue level. In addition, nanoindentation measurements of the bone tissue harvested at femur/tibia from the same patients were compared with the results from the iliac crest biopsy. Young's modulus and hardness values were not significantly different between the two anatomic locations in either cortical or trabecular measurements. The ratio of E/H was not significantly different between the two groups. Results indicate that intrinsic modulus, hardness, and indentation deformation pattern (E/H) of OI bone tissues are not significantly different at long bone (midshaft of femur/tibia) and iliac crest. We observed that age (1.9 to 13.2 years) did not influence OI bone tissue intrinsic mechanical properties.
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Affiliation(s)
- Zaifeng Fan
- Orthopaedic and Rehabilitation Engineering Center, Marquette University, Milwaukee, Wisconsin 53201, USA
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11
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Kamoun-Goldrat AS, Le Merrer MF. Animal models of osteogenesis imperfecta and related syndromes. J Bone Miner Metab 2007; 25:211-8. [PMID: 17593490 DOI: 10.1007/s00774-007-0750-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Accepted: 02/27/2007] [Indexed: 01/24/2023]
Affiliation(s)
- Agnès S Kamoun-Goldrat
- Paris Descartes University, INSERM U781, Tour Lavoisier, Hôpital Necker, 75743, Paris, Cedex 15, France.
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12
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Fan Z, Smith PA, Eckstein EC, Harris GF. Mechanical properties of OI type III bone tissue measured by nanoindentation. J Biomed Mater Res A 2006; 79:71-7. [PMID: 16758461 DOI: 10.1002/jbm.a.30713] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Nanoindentation was used to characterize the intrinsic mechanical properties of bone tissue from eight (8) children with type III Osteogenesis Imperfecta (OI). The bone samples were harvested from the cortex portion at the site of bowing (the mid 2/3 of the shaft of the tibia/femur). Unlike normal bone tissue, OI type III cortical bone exhibited more isotropic material properties. Young's modulus and hardness values measured in the longitudinal direction did not show significant differences from the transverse measurements. No differences were observed in modulus or hardness in an analysis of the cortical and trabecular samples. The deformation patterns of the OI type III bone during nanoindentation were found to be similar to those of normal adult bone in an analysis of the ratio of modulus to hardness. No correlation was found between nanoindentation measurement and age in an analysis of regression.
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Affiliation(s)
- Zaifeng Fan
- Orthopaedic and Rehabilitation Engineering Center, Marquette University, Milwaukee, Wisconsin, USA
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13
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Pithioux M, Lasaygues P, Chabrand P. An alternative ultrasonic method for measuring the elastic properties of cortical bone. J Biomech 2002; 35:961-8. [PMID: 12052398 DOI: 10.1016/s0021-9290(02)00027-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We studied the elastic properties of bone to analyze its mechanical behavior. The basic principles of ultrasonic methods are now well established for varying isotropic media, particularly in the field of biomedical engineering. However, little progress has been made in its application to anisotropic materials. This is largely due to the complex nature of wave propagation in these media. In the present study, the theory of elastic waves is essential because it relates the elastic moduli of a material to the velocity of propagation of these waves along arbitrary directions in a solid. Transducers are generally placed in contact with the samples which are often cubes with parallel faces that are difficult to prepare. The ultrasonic method used here is original, a rough preparation of the bone is sufficient and the sample is rotated. Moreover, to analyze heterogeneity of the structure we measure velocities in different points on the sample. The aim of the present study was to determine in vitro the anisotropic elastic properties of cortical bones. For this purpose, our method allowed measurement of longitudinal and transverse velocities (C(L) and C(T)) in longitudinal (fiber direction) and the radial directions (orthogonal to the fiber direction) of compact bones. Young's modulus E and Poisson's ratio nu, were then deduced from the velocities measured considering the compact bone as transversely isotropic or orthotropic. The results are in line with those of other methods.
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Affiliation(s)
- M Pithioux
- Laboratoire de Mécanique et d'Acoustique, CNRS, 31 Ch. Joseph Aiguier 13402, Marseille, France.
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14
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Lasaygues P, Pithioux M. Ultrasonic characterization of orthotropic elastic bovine bones. ULTRASONICS 2002; 39:567-573. [PMID: 12109547 DOI: 10.1016/s0041-624x(02)00261-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The aim of the present study was to determine the mechanical properties of bovine bones. An ultrasonic method was used to determine acoustical parameters such as the longitudinal and transverse velocities in the longitudinal and two radial directions of compact bone, i.e., in all directions of the plane. Waves propagating through bovine femoral bones were studied using an ultrasonic scanner for linear and sectorial scanning. The mechanical parameters of compact bone, such the Young's modulus and Poisson's ratio in the orthotropic case, were then determined from the measured velocities. The results are in line with those in the literature.
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Affiliation(s)
- P Lasaygues
- Laboratoire de Mécanique et Acoustique, CNRS, Marseille, France.
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