Selective Laser Sintering of 13-93 Bioactive Glass Bone Scaffolds

Bioactive glasses are promising materials for bone scaffolds due to their ability to assist in tissue regeneration. When implanted in vivo, bioactive glasses can convert to hydroxyapatite, the main mineral constituent of human bone and form a strong bond with the surrounding tissues thus providing an advantage over polymer scaffold materials. Bone scaffold fabrication using additive manufacturing techniques like selective laser sintering (SLS) provides control over design and fabrication of pores in the scaffold which helps in mimicking the real human trabecular/cancellous bone. 13-93 bioactive glass, a third-generation bioactive and resorbable material designed to accelerate the body’s natural ability to heal itself, was used in the research described herein to fabricate bone scaffolds using SLS process. 13-93 bioactive glass mixed with stearic acid (as the polymer binder) by ball milling was used as the powder feedstock for the SLS machine. The fabricated green scaffolds underwent binder burnout to remove the stearic acid binder and then sintered at temperatures between 675C and 700C. The sintered scaffolds had pore size varying from 300 μm to 800 μm with 50% apparent porosity and a maximum compressive strength of 24 MPa, among the highest reported for controlled porosity scaffold fabricated with bioactive glasses using SLS process. The scanning electron microscope (SEM) images of the sintered scaffolds shows a rough surface and micro pores ( ≤ 100 μm) in the walls throw in together with the oriented internal architecture could be encouraging for tissue engineering applications. The X-ray diffraction (XRD) analysis on the sintered scaffolds confirmed the chemical composition of the 13-93 bioactive glass with no signs of crystallization.