Highly porous biomaterials with a structure close to that of cancellous bone have been prepared using biogenic hydroxyapatite and glass of the SiO2-Na2O-CaO system by a replication of the polymer template structure. It has been established that during sintering of the samples the hydroxyapatite decomposes, which involves the formation of glass-ceramics containing phases of renanit NaCaPO4, calcium phosphate silicate Ca5(PO4)2SiO4, calcium pyrophosphate Ca2P2O7 and impurities of hydroxyapatite Ca5(PO4)3(OH). Structural characteristics and mechanical properties of the obtained materials are promising for the replacement of defective cancellous bone.

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The work is devoted to investigation of porous glass-ceramic composite materials on the basis of biogenic hydroxyapatite and sodium borosilicate glass prepared from starting powders with different particle sizes (<50 ?m and <160 ?m). Starting hydroxyapatite/glass weight ratio was 1.0/0.46 and sintering temperature was ~800?C. Microstructural characterization of the surface and fracture of the samples revealed a decrease in sizes of grains and pores with decreasing the particle size of the precursor powder. However, porosity of the composites practically did not depend on the particle size and was equal to 32.5-33.0%. The same tendency was observed for the compression strength (66-67MPa). However, investigation of structural-mechanical properties using an indentation method, where dominant load is applied to the surface layers of sample, showed up the effect of the particle size of the starting powder on the mechanical properties of the composites: the smaller particle size, the higher mechanical properties.

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