Biological activity of a SiO2-CaO-P2O5 sol-gel glass highlighted by PIXE-RBS methods

TL;DR

This study uses PIXE and RBS techniques to analyze how P2O5 influences apatite layer formation on SiO2-CaO-P2O5 bioactive glass, showing phosphorus enhances bone bonding potential.

Contribution

It demonstrates the impact of P2O5 on apatite formation and bone bonding ability in sol-gel derived bioactive glass using advanced elemental analysis methods.

Findings

Presence of P2O5 accelerates apatite layer formation.

Calcium phosphate layer with magnesium forms after days.

P2O5 improves chemical bonding with bone in vivo.

Abstract

It is proposed in this study to observe the influence of P2O5 on the formation of the apatite-like layer in a bioactive glass via a complete PIXE characterization. A glass in the SiO2-CaO-P2O5 ternary system was elaborated by sol-gel processing. Glass samples were soaked in biological fluids for periods up to 10 days. The surface changes were characterized using Particle Induced X-ray Emission (PIXE) associated to Rutherford Backscattering Spectroscopy (RBS), which are efficient methods for multielemental analysis. Elemental maps of major and trace elements were obtained at a micrometer scale and revealed the bone bonding ability of the material. The formation of a calcium phosphate-rich layer containing magnesium occurs after a few days of interaction. We demonstrate that the presence of phosphorus in the material has an impact on the development and the formation rate of the bone-like apatite layer. Indeed, the Ca/P atomic ratio at the glass/biological fluids interface is closer to the nominal value of pure apatite compared to P2O5 free glasses. It would permit, in vivo, an improved chemical bond between the biomaterials and bone.