Gelatinizing technology combined with gas foaming to fabricate porous spherical hydroxyapatite bioceramic granules

This study fabricated porous spherical hydroxyapatite (HA) bioceramic granules via a novel method by combining the ionotropic gelation of sodium alginate with H2O2 gas-foaming. Firstly, HA powder was dispersed in sodium alginate solution; then, the bubbly slurry prepared by H2O2 gas-foaming was dripped into CaCl2 solution to form hydrogel spheres; finally, these hydrogel spheres were washed, dried and sintered to obtain the HA bioceramic granules. SEM images revealed that the obtained HA granules exhibited spherical shape and interconnected porous structure. XRD, FT-IR and ICP-OES tests confirmed the phase composition and the purity of the HA spherical granules. Compared with commercialized HA irregular granules (BAM(center dot) P2040), the HA spherical granules had smaller grain size, more micropores, larger specific surface area and stronger protein adsorption ability. Therefore, the porous spherical HA bioceramic granules shows potential to be a good candidate for bone defect filling materials.