Scaffolds Prepared with Bovine Hydroxyapatite Composites by 3D Printing

The bovine hydroxyapatite (BHA) was applied to prepare biological tissue engineering scaffolds by the method of extrusion freeforming. To achieve this goal, BHA were added to sodium alginate (SA) solution to form a slurry system in appropriate proportion. The resulting mixtures were fabricated to be a kind of controllable and porous scaffolds followed with cross-linking in 5% calcium chloride (CaCl2) solution for 24 h. After that, the scaffolds were sintered in air at 1 000, 1 100, 1 200 and 1 300 °C for 5 h. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies were performed on the scaffolds to analyze its microstructure and constituent. To explore the effect of sintering temperature on scaffolds, the compressive strength, volume shrinkage and water absorptivity of BHA-SA composite scaffolds after sintering were investigated. The research tests indicated the feasibility of applying BHA powder to 3D printing. Besides, the scaffolds sintered in a respectively lower temperature possess much more pores and performed higher water absorptivity, which means better cellular affinity. And scaffolds sintered between 1 100 and 1 200 °C presents higher compressive strength.