Borophosphate glass-ceramic scaffolds by a sodium silicate bonding process

A borophosphate glass with the mol% composition 25Na2O-25CaO-5P2O3-45B2O5 was melted. The crystalline phase rheanite crystallized spontaneously during cooling the sample. Porous glass-ceramic scaffolds were prepared by bonding glass particles with size distributions in the range of approximately 100–500 μm by 0.1 M Na2SiO3 solutions. The scaffolds porosities were 40 ~ 60% and their compressive strengths were 0.1 ~ 0.4 MPa. The conversion of the binding scaffolds to hydroxyapatite (HA) was investigated by measuring the weight loss after soaking the sample in a solution of 0.25 M K2HPO4 with a pH value of 9.0 at 37 °C as a function of time. Hydroxyapatite (HA) was observed by XRD and SEM after soaking for 7 days. Cell attachment, spreading and proliferation on both unconverted scaffolds and on scaffolds coated with HA were determined by MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay method using Murine osteoblastic-like MC3T3-E1 cells. The scaffolds are biocompatible and their biocompatibility is enhanced after the formation of a HA layer.