Fabrication of nanostructured hierarchical coatings composed of calcium phosphate/titanate on titanium substrate

摘要

Titanium (Ti) and its alloys have been widely used in orthopedic and dental applications. The bonding between Ti implants and tissues is significantly important in the clinical applications, which is highly relative to the characteristics of implant surface with surface improvement by various coatings such as hydroxyapatite (HA). Meanwhile, the characteristics of modified implants surface can induce special biological response of osteogenic cells to improve the bone-implant bonding. In this paper, in order to improve Ti bioactivity and enhance its osteointegration, calcium phosphate (CaP)/titanate coatings were prepared on Ti with nano-scale surface topographies by a two-step hydrothermal process. Firstly, titanium meshes were treated in sodium hydroxide solutions at two temperatures (200 °C or 240 °C). Then, the treated meshes were immersed in calcium phosphate solutions containing various concentrations of cyclohexane-hexacarboxylic acid (H6L) under hydrothermal conditions. After this two-step process, calcium phosphate deposits, confirmed to be apatite/titanate by energy dispersive X-ray spectroscopy, were successfully formed on the treated Ti mesh surface. These results suggested that this two-step hydrothermal method can be successfully applied to fabricate robust and hierarchical nanostructured coatings of CaP/titanate on Ti implants.