Bone Abstracts

The bioapatite crystals have a multilayer hydrate shell, which contains impurity ions such as magnesium, sodium, potassium and it is not clear the qualitative and quantitative characteristics of noapatite entourage. The major component noapatite environment in bone is water and we studied the surface of nanocrystals from trabecular bone in healthy rats and during the water deficiency.

In experiment we use adult laboratory rats (8 months age), remove the calcaneal bone, clean it from muscles and tendons and dry it to the constant weight. The specimen was burn in temperature from 560 to 760 °C and dissolved in distilled deionized water and treated with ultrasound. In this solution was determined content of calcium, magnesium, potassium and sodium by atomic absorption method.

Pyrolytic degradation of crystals surrounding at 680 °C causes a rise of soluble Ca²⁺ concentration that was significant higher in case of dehydratation. This effect shows a high Ca²⁺ concentration in the noapatite component and a defect structure of apatite crystals.

Mg²⁺ ions at the temperature 700–750 °C moves from the bound to a labile state on the nanocrystals surface which may indicate an increase of the crystallites size, disappearance of lattice microdeformations, and decomposition of carbonate biomineral complexes. The concentration of the ‘labile’ Ca²⁺ at the same temperatures significant decrease that may indicates their transition from the surface layer to the apatite grate. Counter migration of Mg²⁺ and Ca²⁺ in samples from the experimental pathology (‘dehydration’) begins at a lower temperature than in control samples. Active mobility of K and Na in the samples with dehydration confirms the fact of defective crystal structure.

Thus, our research have shown the ability of replacement the vacant places of water by the trace elements that may affect structural integrity of bone apatite.