Suitability of Biosilicate® glass-ceramic powder for additive manufacturing of highly porous scaffolds

The Biosilicate® glass-ceramic is one of the most promising alternatives to the 45S5 Bioglass® in terms of bioactivity, osteoconductivity, osteoinductivity, non-cytotoxicity, and antibacterial properties, with significant advantages in the manufacturing of specific components of complex shapes for bone tissue application. Unlike in 45S5 glass, the crystallization does not lead to a degradation of bioactivity. In the present paper, we explored the suitability of Biosilicate® for the manufacturing of highly porous scaffolds (porosity of 50–80 vol%) by using modern additive manufacturing technologies, such as direct ink writing (DIW) and digital light processing (DLP). Both techniques could be easily applied to fine powders of Biosilicate® mixed with fugitive binders. Significant densification of the struts, despite the limited powder packing, could be achieved using liquid-assisted sintering, in turn, triggered by the phosphate-enriched residual glass phase, already at 1000 °C. The strength-to-density ratio could be variously tuned (from 1.5 to 9.5 MPa cm3/g), especially with DLP-derived samples, by adjusting both the firing temperature and the scaffold topology.