This study is devoted to the comparison of strength characteristics in the process of deformation and damage of axially strained VT1-0 titanium in the ultrafinegrained (UFG) and coarse-grained (CG) states. The temperature distributions on the surface of titanium specimens were recorded by means of IR thermography. The VT1-0 titanium in UFG state formed by applying severe plastic deformation is characterized by twice the yield stress and strength limit but half the deformation limit compared to CG titanium. The fracture of CG titanium is accompanied by local powerful generation of heat, while, in UFG titanium, the damage nuclei are less intense and more evenly distributed over the fracture cross-section. The titanium in UFG state, being deformed, utilizes structural channels of energy absorption more efficiently than in the CG state by involving the whole deformed volume in the fracturing process.

To perform comparative study of composition and strength properties of osteoplastic biomaterials subjected to technological processing. Material and Methods. Specimens of native (initial) and deproteinized bone tissue were analyzed. Strength properties of specimens were studied by single-axis static extension with automatic recording of load curves. Load-extension curves were used to calculate mechanical parameters: proportionality limit, strength limit, relative deformation before destruction, and the Young's module. Dependence between a processing type and changes in the surface morphology, element composition, overall dimensions, and dry weight of specimens was identified. Results. All bone tissue specimens had small amount of deformation typical for fragile materials -1 %. Proportionality limit for native bone tissue was 27 MPa, and that for deproteinized tissue -29 MPa. Strength limit did bone on the type of chemical processing of tissue and had the value of 80-90 MPa. Collagen presence influenced the Young's module which was 110 MPa in deproteinized bone tissue, two-fold decreased from that in initial bone tissue (230 MPa). Topography of specimens and fracture surfaces were more pronounced after deproteinization. Conclusion.The study of physical and mechanical properties and composition of compact bone specimens gives an understanding of processing type influence on bone tissue structure and properties.

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Strontium ranelate (29 μg/ml) and ibandronic acid (50 μM) produced a cytotoxic effect on rat bone marrow myelokaryocytes in vitro. Strontium ranelate increased the number of myelokaryocytes with signs of necrosis, ibandronic acid increased the number of apoptotic and necrotic cells in the 9-day 2D culture of bone marrow cells on the plastic surface of the wells of culture plates. Co-culturing of the bone marrow with 3D matrices with microarc calcium phosphate coating that simulated bone mineral matrix increased intracellular ROS concentration, but abolished the cytotoxic effect of these drugs.