The fabrication and characterization of bioactive Akermanite/Octacalcium phosphate glass-ceramic scaffolds produced via PDC method

Abstract

In the present study, a bioactive silicate-phosphate glass-ceramic scaffold was fabricated via the polymer-derived ceramics (PDC) method. K2HPO4 phosphate salt was used as the P2O5 precursor in this method. The effect of K2HPO4 wt% and heat treatment temperatures (900–1100 °C) was evaluated. It was observed that although increasing the wt% of K2HPO4 led to the formation of scaffolds with higher densities and strengths, it could also increase the formation of the calcium phase, which could result in improper release behavior of scaffolds. On the other hand, higher heat treatment temperatures enhanced the strength of the scaffolds but eliminated the bioactive octacalcium phosphate (OCP) phase. X-ray diffraction (XRD) analysis showed that the dissolution of the OCP phase in simulated body fluid (SBF) resulted in precipitation of hydroxyapatite (HA) on the scaffold surface which enhanced the bioactivity. Furthermore, based on microstructural studies by Scanning Electron Microscopy (SEM), the fabricated scaffold possessed a wide range of pore sizes, appropriate for osteointegration and bone formation. The optimum wt% of phosphate salt was less than 6 wt% and the optimum heat treatment temperature was 1000 °C. After the optimization of compositions and processing, Alamar Blue Assay was used to evaluate HOb cell cultures, showing a continuous proliferation for the optimized samples.