Bioactive sol-gel coatings for orthopaedic prosthesis

Sol-gel materials have been proposed in last years for clinical application s. In this work, bioactive sol-gel coatings were prepared from suspensions of up to 25% wt. of bioactive glass (CaO . SiO2.P2O5) particles in a hybrid sol obtained from TEOS and MTES. Thick dip-coatings showed in vitro bioact ivity after a few days, but glass-particles dissolution promotes a slight r eduction in the corrosion resistance. In order to overpass this problem, a two-stage sol-gel coating system that includes a first SiO2 hybrid film, ac ting as barrier against corrosion, and an external bioactive layer from gla ss particle suspension is proposed. The obtained samples revealed significa nt improvement in their electrochemical behaviour, and showed in vitro bioa ctivity.