Direct ink writing of highly bioactive glasses

Direct ink writing (DIW), or Robocasting, is an additive manufacturing technique that offers the opportunity to create patient specific bioactive glass scaffolds and high strength scaffolds for bone repair. The original 45S5 Bioglass^® composition crystallises during sintering and until now, robocast glass scaffolds contained at least 51.9mol% SiO₂ or B₂O₃ to maintain their amorphous structure. Here, ICIE16 and PSrBG compositions, containing <50mol% SiO₂, giving silicate network connectivity close to that of 45S5, were robocast and compared to 13-93 composition. Results showed Pluronic F-127 can be used as a universal binder regardless of glass reactivity and that particle size distribution affected the ink "printability". Scaffolds with interconnects of 150μm (41-43% porosity) had compressive strengths of 32-48MPa, depending on the glass composition. Robocast scaffolds from these highly reactive bioactive glasses promise greatly improved bone regeneration rates compared with existing bioactive glass scaffolds.