CHEMICAL SURFACE-TREATMENT OF SILICONE FOR INDUCING ITS BIOACTIVITY

It has been confirmed that the apatite nucleation is induced by silano l (SI-OH) groups formed on the surfaces of materials and/or silicate i ons adsorbed on them. It was previously shown-that apatite nuclei are formed on organic polymers when the polymers a re placed on CaO, SiO2- based glass particles soaked in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma, and that t hey grow spontaneously to form a dense and uniform apatite layer toget her with high adhesive strength to the substrates when the polymers ar e soaked in another solution with ion concentrations 1.5 times the SBF . in the present study, silanol groups bonded covalently to the surfac e of the silicone substrate were formed and its apatite-forming abilit y was examined. When silicone substrates were treated with 5 or 10 M N aOH with pH 7.25 at 36.5 degrees C for more than 3 h, silanol groups w ere formed on the surfaces of the substrates. When th us NaOH-treated substrates were soaked in 1.5SBF at 36.5 degrees C, a bone-like apatit e was formed on the substrates in a short period. (C) 1998 Chapman & H all.