Fluorophosphate bio-glass for bone tissue engineering: in vitro and in vivo study

The objective of the work is to investigate the influence of fluoride in the bioactivity of phosphate bio-glass to utilise in bone tissue engineering. The fluorophosphate bio-glass system was formulated by varying fluoride content in phosphate-based glass 45P₂O₅-(30-X)-CaO-25Na₂O-XCaF₂ (X = 0, 1.25, 2.5, 3.75, and 5.0) using melt quenching technique. The elemental composition and fluoride retention in the prepared material was investigated by X-ray photoelectron spectroscopy. The bioactivity test in simulated body-fluid (SBF) exhibited apatite layer and its bone bonding ability which was characterized by X-ray diffraction patterns and Fourier Transform Infrared Spectrophotometer spectra. The viability of human gastric adenocarcinoma (AGS) and MG-63 cells of the bio-glass confirmed the nontoxic nature. In vivo studies demonstrated the conversion of the fluorophosphate glass to bone in the femoral condyle of the rabbit. After ten weeks, scanning electron microscope with energy dispersive X-ray spectrograph (SEM_EDAX) and confocal laser scanning microscopy examinations revealed the resorption rate and bone-glass interface qualitatively and quantitatively. Consequently, the biocompatible and bioresorbable nature of the fluorophosphate bioglass can be exploited as a potential bone graft substitute in the near future.