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Human cortical and trabecular bones are formed by individual osteons and bone packets, respectively, which are produced at different time points during the (re)modeling cycle by the coupled activity of bone cells. This leads to a heterogeneously mineralized bone material with a characteristic bone mineralization density distribution (BMDD) reflecting bone(More)
Several recent results are suggesting that the collagen packing in mineralized tissues is much less regular than in the case of other nonmineralizing collagen, e.g., rat tail tendon. To clarify this question we have investigated the molecular arrangement in mineralized and unmineralized turkey leg tendon as a model for the collagen of mineralized tissues.(More)
Natural materials such as bone, tooth, and nacre are nanocomposites of proteins and minerals with superior strength. Why is the nanometer scale so important to such materials? Can we learn from this to produce superior nanomaterials in the laboratory? These questions motivate the present study where we show that the nanocomposites in nature exhibit a(More)
Osteogenesis imperfecta (OI) is a disease attributable to any of a large number of possible mutations of type I collagen. The disease is clinically characterized in part by highly brittle bone, the cause of this feature being unknown. Recently a mouse model of OI, designated as osteogenesis imperfecta murine (oim), and having a well defined genetic(More)
The degree of mineralization of bone matrix is an important factor in determining the mechanical competence of bone. The remodeling and modeling activities of bone cells together with the time course of mineralization of newly formed bone matrix generate a characteristic bone mineralization density distribution (BMDD). In this study we investigated the(More)
Collagen fibrils resemble smectic, liquid crystals in being highly ordered axially but relatively disordered laterally. In some connective tissues, x-ray diffraction reveals three-dimensional crystallinity in the molecular packing within fibrils, although the continued presence of diffuse scatter indicates significant underlying disorder. In addition,(More)
Tissue formation is determined by uncountable biochemical signals between cells; in addition, physical parameters have been shown to exhibit significant effects on the level of the single cell. Beyond the cell, however, there is still no quantitative understanding of how geometry affects tissue growth, which is of much significance for bone healing and(More)
The mechanism of active stress generation in tension wood is still not fully understood. To characterize the functional interdependency between the G-layer and the secondary cell wall, nanostructural characterization and mechanical tests were performed on native tension wood tissues of poplar (Populus nigra x Populus deltoids) and on tissues in which the(More)
The remarkable mechanical properties of biological materials reside in their complex hierarchical architecture and in specific molecular mechanistic phenomena. The fundamental importance of molecular interactions and bond recovery has been suggested by studies on deformation and fracture of bone and nacre. Like these mineral-based materials, wood also(More)
Scaffolds for tissue engineering are usually designed to support cell viability with large adhesion surfaces and high permeability to nutrients and oxygen. Recent experiments support the idea that, in addition to surface roughness, elasticity and chemistry, the macroscopic geometry of the substrate also contributes to control the kinetics of tissue(More)