Freeform extrusion fabrication of titanium fiber reinforced 13–93 bioactive glass scaffolds

Abstract Although implants made with bioactive glass have shown promising results for bone repair, their application in repairing load-bearing long bone is limited due to their poor mechanical properties in comparison to human bone. This work investigates the freeform extrusion fabrication of bioactive silicate 13–93 glass scaffolds reinforced with titanium (Ti) fibers. A composite paste prepared with 13–93 glass and Ti fibers (~16 µm in diameter and lengths varying from ~200 µm to ~2 mm) was extruded through a nozzle to fabricate scaffolds (0–90° filament orientation pattern) on a heated plate. The sintered scaffolds measured pore sizes ranging from 400 to 800 µm and a porosity of ~50%. Scaffolds with 0.4 vol% Ti fibers measured fracture toughness of ~0.8 MPa m 1/2 and a flexural strength of ~15 MPa. 13–93 glass scaffolds without Ti fibers had a toughness of ~0.5 MPa m 1/2 and a strength of ~10 MPa. The addition of Ti fibers increased the fracture toughness of the scaffolds by ~70% and flexural strength by ~40%. The scaffolds’ biocompatibility and their degradation in mechanical properties in vitro were assessed by immersing the scaffolds in a simulated body fluid over a period of one to four weeks.