Biomimetic method for obtaining hydroxyapatite

Coating of bioinerts or biotolerable materials with a bioactive layer, generally composed of hydroxyapatite (HA), has been currently used when one wishes to combine bioactivity and material properties. Coating methods include: plasma and name spray, sputtering, electrophoresis and electrolysis. Except the electrolytic one, all other methods involve high working temperatures. Therefore, the physical and chemical characteristics of hydroxyapatite can be affected, with possible consequences on the behavior of the implanted material. A recently proposed method named biomimetic, can be employed to coat several types of substrates through precipitation of a hydroxyapatite layer. This approach imitates the biological natural conditions of hydroxyapatite formation, through control of temperature, pH and concentration of ionic species. In this work, barium titanate substracts were coated with hydroxyapatite and characterized by X-ray diffraction, infrared spectroscopy and scanning electron microscopy.