Developing porous diopside/hydroxyapatite bio-composite scaffolds via a combination of freeze-drying and coating process

The development of diopside/hydroxyapatite (DP/HA) bio-composite scaffolds, that possess an interconnected pore architecture via the combination of freeze-drying and coating process was studied. For coating the freeze-drying HA scaffolds by diopside, various impregnation times (1, 3, and 5 days) were applied, and followed by a sintering process at 950 °C. The alterations in microstructure, physico-mechanical behaviour and phase composition of the produced composites were investigated. In vitro bioactivity and degradation studies of the selected composite were also carried out. The results demonstrated that the diffusion of diopside within the hydroxyapatite scaffolds during the coating process improved the compressive strength of the composite material. HA scaffolds coated with diopside for 3 days were chosen for the remaining study due to their combination of adequate interconnected porosity (60.54 ± 1.02%) and suitable compressive strength (1.23 ± 0.04 MPa). The good bioactivity of DP/HA scaffolds was detected through the genesis of an apatite layer over the surface and their acceptable degradation rate in comparison to that of the blank HA scaffold.