Preparation and in vitro bioactivity of zinc containing sol-gel-derived bioglass materials

Bioactive glass material of the type CaO--P(2)O(5)--SiO(2)--ZnO was obtained by the sol-gel processing method. This material was produced both in powder and in disks form by compression of the powder. The obtained material was characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and surface electron micrograph (SEM). The bioactivity was examined in vitro with respect to the ability of hydroxyapatite layer to form on the surface as a result of contact with simulated body fluid (SBF). The XRD and FTIR studies were conducted before and after contact of the material with SBF. The gel-derived materials were amorphous as shown by XRD, but were able to crystallize calcium phosphates on their surfaces when exposed to SBF. We also examined the alkaline phosphatase (AP) activity of osteoblasts, using human fetal osteoblastic cells (hFOB 1.19) cultured on the zinc bioglass, and compared it with the polystyrene plates. The bone cells consistently expressed higher AP activity in the zinc bioglass materials compared with the polystyrene plates, which indicates the zinc containing composition stimulates bone cells production of AP.