Preparation and characterization of hydroxyapatite–sodium alginate scaffolds by extrusion freeforming

Extrusion freeforming is a facile approach to produce complex 3D structures with controlled architecture and porosity. In this work, a new slurry system, mainly containing hydroxyapatite (HA) and sodium alginate (SA), has been used to fabricate porous hydroxyapatite scaffolds. After cross-linking in 5% calcium chloride (CaCl2) solution for 24 h, HA–SA composite scaffolds were sintered at 1000–1300 °C for 2 h. The properties of HA–SA composite scaffolds before and after sintering have been investigated. The new slurry system has greatly improved the quality of porous hydroxyapatite scaffolds.