David H. Kohn

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Strategies to engineer bone tissue have focused on either: (1) the use of scaffolds for osteogenic cell transplantation or as conductive substrates for guided bone regeneration; or (2) release of inductive bioactive factors from these scaffold materials. This study describes an approach to add an inductive component to an osteoconductive scaffold for bone(More)
The bone diagnostic instrument (BDI) is being developed with the long-term goal of providing a way for researchers and clinicians to measure bone material properties of human bone in vivo. Such measurements could contribute to the overall assessment of bone fragility in the future. Here, we describe an improved BDI, the Osteoprobe IItrade mark. In the(More)
Fracture risk and mechanical competence of bone are functions of bone mass and tissue quality, which in turn are dependent on the bone's mechanical environment. Male mice have a greater response to non-weight-bearing exercise than females, resulting in larger, stronger bones compared with control animals. The aim of this study was to test the hypothesis(More)
Raman spectroscopic markers have been determined for fatigue-related microdamage in bovine bone. Microdamage was induced using a cyclic fatigue loading regime. After loading, the specimens were stained en-bloc with basic fuchsin to facilitate damage visualization and differentiate fatigue-induced damage from cracks generated during subsequent histological(More)
Hydrogen-bearing species in the bone mineral environment were investigated using solid-state NMR spectroscopy of powdered bone, deproteinated bone, and B-type carbonated apatite. Using magic-angle spinning and cross-polarization techniques three types of structurally-bound water were observed in these materials. Two of these water types occupy vacancies(More)
Collagen cross-linking is altered in many diseases of bone, and enzymatic collagen cross-links are important to bone quality, as evidenced by losses of strength after lysyl oxidase inhibition (lathyrism). We hypothesized that cross-links also contribute directly to bone fracture toughness. A mouse model of lathyrism using subcutaneous injection of up to 500(More)
The mechanical properties of bone are dictated by its amount, distribution and 'quality'. The composition of the mineral and matrix phases is integral to defining 'bone quality'. Exercise can potentially increase resistance to fracture, yet the effects of exercise on skeletal fragility, and how alterations in fragility are modulated by the amount,(More)
Here we describe modifications that allow the bone diagnostic instrument (BDI) [P. Hansma et al., Rev. Sci. Instrum. 79, 064303 (2008); Rev. Sci. Instrum. 77, 075105 (2006)], developed to test human bone, to test the femora of mice. These modifications include reducing the effective weight of the instrument on the bone, designing and fabricating new probe(More)
UNLABELLED NMR was used to study the nanostructure of bone tissue. Distance measurements show that the first water layer at the surface of the mineral in cortical bone is structured. This water may serve to couple the mineral to the organic matrix and may play a role in deformation. INTRODUCTION The unique mechanical characteristics of bone tissue have(More)
Raman spectroscopy and imaging are known to be valuable tools for the analysis of bone, the determination of protein secondary structure, and the study of the composition of crystalline materials. We have utilized all of these attributes to examine how mechanical loading and the resulting deformation affects bone ultrastructure, addressing the hypothesis(More)