Porous and Strong Bioactive Glass (13-93) Scaffolds Fabricated by Freeze Extrusion Technique

Scaffolds fabricated by current methods often lack the combination of high strength and high porosity for skeletal substitution of load-bearing bones. In this work, freeze extrusion fabrication (FEF), a solid freeform fabrication technique, was investigated for the creation of porous and strong bioactive glass (13-93) scaffolds for potential applications in the repair of loaded bone. The process parameters for forming three-dimensional (3D) scaffolds with a pre-designed, grid-like microstructure by FEF were determined. Following thermal treatment of the as-formed constructs at temperatures up to 700 °C, scaffolds consisting of dense glass struts and interconnecting pores (porosity ≈ 50%; pore width ≈ 300 μm) were obtained. These scaffolds showed an elastic mechanical response in compression, with a compressive strength of 140 ± 70 MPa and an elastic modulus of 5.5 ± 0.5 GPa, comparable to the values for human cortical bone. The scaffolds supported the proliferation of osteogenic cells in vitro, showing their biocompatibility. These results indicate that 13-93 bioactive glass scaffolds created by the FEF method could have potential application in the repair and regeneration of load-bearing bones.