Analysis of in vitro reaction layers formed on 48S4 glass for applications in biomaterial field

¹ Équipe Chimie du Solide et Matériaux, UMR 6226 Sciences Chimiques de Rennes Campus de Beaulieu, Bât. 10 B, avenue du général Leclerc, 35042 Rennes Cedex, France
² Laboratoire de Physico-chimie des matériaux, Département de physique, Faculté des Sciences de Monastir, avenue de l'environnement, 5019 Monastir, Tunisia

Corresponding author: hassane.oudadesse@univ-rennes1.fr

Received: 1 February 2007
Revised: 3 April 2007
Accepted: 3 August 2007
Published online: 21 September 2007

Abstract

The purpose of this work is to study the formation of hydroxyapatite (Ca₁₀ (PO₄)₆(OH)₂) on the surface of glass 48S4 with chemical composition: SiO₂: 48%, CaO: 30%, Na₂O: 18% and P₂O₅: 4% in weight ratio. This selected composition presents phosphorus contributions lower than that in Bioglass^® [Hench et al. J. Biomed. Mater. 36, 117 (1971)] developed by L. Hench. Comparison of the kinetic formation of hydroxyapatite on the glass surfaces of these two biomaterials was made. The Material was prepared by melting and rapid quenching. It shows a bioactive character. This phenomenon is confirmed by the “in vitro” formation of hydroxycarbonate apatite (HCA) layer on the surface of glass after immersion in the Simulated Body Fluid (SBF). Before immersion in SBF, The proposed composition of glass was analyzed using several physicochemical methods like XRD, FTIR, SEM, and EDS confirming the composition and its amorphous state well. The pellets were soaked in SBF for 2 h, 1, 3, 7 and 15 days at 37 °C. The analyses of SBF after each immersion time were carried out using ICP-OES method. Results show important exchanges of ions between the surface of glass and the SBF. They revealed the formation of an amorphous CaO-P₂O₅- rich layer on the surface of the specimens after 1 day in the solution and a crystalline HCA layer after 3 days immersion time as will be shown by XRD, EDS and FTIR analysis. The cristallinity increases with immersion time. After 15 days immersion in SBF liquid, the specimens are still fully covered by hydroxycarbonate apatite (HCA) layer.