M.Z. Fedorova, S.V. Nadezhdin, Y.R. Kolobov, M.B. Ivanov, N.A. Pavlov, E.V. Zubareva
There has been carrried out an estimation of the osteogenic properties of the coatings on the base of the nanostructural hydroxylapatite (nano-HAP) with various physico-chemical characteristics. The samples for implantation were made from the “VT-16” titan. The first type of coating was achieved by means of spreading nano-HAP from solution of electrolyte with simultaneous forming of TiO2 layer. The second type – two-layer coating was achieved in stages. First the porous layer of TiO2 was formed and then the colloidal nano-HAP was spread using sol-gel method. The inflammatory and immune reactions were estimated by the concentration of C-reactive protein and interleukin-1β in blood plasma of experimental animals with the help of the immunofermental analizator. The estimation of derived implantats with bone fragments was carried out on the scanning electronic microscope Quanta 200. The histological preparations were made from the bone fragments and then were investigated using the hardware program complex Video-Test-Size (Saint-Petersburg).
The investigation has shown that the destinctions by the concentration of SRB and IL-1β in rats' blood plasma had neither falsely operated nor operated rats. This is the evidence of inflammatory and immune reactions' absence on the implantat. The analysis of the electron-diffraction and histological samples has shown that on the estimated types of coatings of titan implantats the neoplasm of the bone tissue was differed in types and rate of forming of bone structural elements.
The chaotic located fibrillar structures were revealed on the implantats with the combine calcium-phospate coating, and in the sites of contact of the implantat coating with the bone - fine-fibre formations and bone trabecula. The phase character of osteogenesis was distinctly observed on the histologic samples with combine calcium-phospate coating: the intensive formation of fibrous intercellular substance and slowed maturing of cellular elements. The investigation of the implantat -tissue contact area among the samples with two-layer composite coating showed the presence of the neogenic bone trabecula without “free” fibrous connective tissue structures. The data received using the light microscopy were also confirmed by the scanning electronic microscopy. The two-layer composite coating provided at the same time the forming of more mature connective tissue. The cause of this phenomenon was better bioavailability of the coating material. The properties of the combine calcium-phospate coating can be estimated mainly as osteoconductive, and two-layer composite coating – as osteoinductive.