In vitro study of bone-like apatite coatings on metallic fiber braids

Polymer, ceramic and metal are wildly applied in orthopedic and dental materials. However, most metal including titanium, titanium alloy and 316L stainless steel do not posses bioactivities to bond with bone tissue. For improving this weakness, we incubated titanium wire and 316L stainless steel fiber into the simulated body fluid (SBF) after alkaline and thermal treatments to form a bone-like apatite layer on it. With the reaction, the coating was formed on the surface of metal and it can induce apatite nucleus appear on the surface. The surface appearance was observed and the chemical constitution of bone-like apatite was examined. As the result show, when the titanium wire and 316L stainless steel fiber treated with 5 M NaOH aqueous solution, subsequently heated at 400 °C and soaked into SBF at a temperature of 80 °C increase the possibility of nucleation of considerable quantities of bone-like hydroxyapatite. We also found the main components of both the HA structures were Ca and P, and the percentage Ca/P were 1.69 and 1.1, which is similar to that of a natural bone.