title: Anisotropy in the compressive mechanical properties of bovine cortical bone and the mineral and protein constituents.
abstract: The mechanical properties of fully demineralized, fully deproteinized and untreated cortical bovine femur bone were investigated by compression testing in three anatomical directions (longitudinal, radial and transverse). The weighted sum of the stress-strain curves of the treated bones was far lower than that of the untreated bone, indicating a strong molecular and/or mechanical interaction between the collagen matrix and the mineral phase. Demineralization and deproteinization of the bone demonstrated that contiguous, stand-alone structures result, showing that bone can be considered an interpenetrating composite material. Structural features of the samples from all groups were studied by optical and scanning electron microscopy. Anisotropic mechanical properties were observed: the radial direction was found to be the strongest for untreated bone, while the longitudinal one was found to be the strongest for deproteinized and demineralized bones. A possible explanation for this phenomenon is the difference in bone microstructure in the radial and longitudinal directions.
authors.affiliation: Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093, USA. eevdokim@ucsd.edu
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Novitskaya
authors.forename: Po-Yu
authors.initials: PY
authors.lastname: Chen
authors.forename: Steve
authors.initials: S
authors.lastname: Lee
authors.forename: Ana
authors.initials: A
authors.lastname: Castro-Ceseña
authors.forename: Gustavo
authors.initials: G
authors.lastname: Hirata
authors.forename: Vlado A
authors.initials: VA
authors.lastname: Lubarda
authors.forename: Joanna
authors.initials: J
authors.lastname: McKittrick
mesh_terms: D000818:Animals; D016880:Anisotropy; D001696:Biomechanical Phenomena / Q000502:physiology; D001842:Bone and Bones / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D002417:Cattle; D019245:Compressive Strength / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology; D008903:Minerals / Q000032:analysis*; D016062:Porosity; D011506:Proteins / Q000032:analysis*; D013314:Stress, Mechanical
chemical_list: D008903:Minerals; D011506:Proteins