Biomimetic coating of bone-like apatite on glass beads

Soda lime glass beads were chemically treated by either an aqueous solution of NaOH (3 mol/l) or a hydrogen peroxide solution (30 vol%) containing TaCl5 in 5x10(-3) mol/l or by both of them. The treated samples were soaked up to 14 days in a simulated body fluid (SBF): Na+ 142.0, K(+)5.0, Ca2+ 2.5, Mg2+ 1.5, Cl- 147.8, HCO3- 4.2, HPO42- 1.0, SO42- 0.5 (in 10(-3) mol/l), or in another solution 1.5 times as concentrated as SBF (1.5SBF). The SBFs were kept at 36.5degreesC and at 7.25 in pH. Apatite was deposited on the samples treated with the NaOH solution, the H2O2/Ta solution, and both of them before soaking in 1.5SBF. Ta(V) ions were present on not only the samples treated with the H2O2/Ta solution but those treated with both NaOH and the H2O2/Ta solutions. It was concluded that Ta(V) ions on the surface layer had ability of inducing apatite deposition, and the ability was enhanced by the coexistence with silanol groups.