Advanced Bioceramics from Vat-Photopolymerizations Silicone-Based Emulsions: from Bioglass to Oxynitrides

A recent approach has evidenced the feasibility of 70S30C (70 mol% SiO 2 , 30 mol% CaO) bioglass-based highly porous composite scaffolds from photocurable silicone-based emulsions containing dispersion of molten calcium nitrate tetrahydrate nanodroplets in a silicone-acrylate blend, also comprising fumed silica. This contribution aims at presenting substantial refinements of the technology. First, the suppression of fumed silica, implying the generation of fully liquid feedstock, improves the accuracy of masked stereolithography 3D printing. Second, the firing above 700 °C is considered for the conversion into advanced ceramic composites, particularly above 1200 °C, with pyrolytic carbon favouring carbothermal reduction and nitridation. Scaffolds comprising oxynitride phases are shown to combine high porosity with exceptional compressive strength. Preliminary biomaterial testing displays a rapid hydroxyapatite formation with only mild pH increases, indicating favourable dissolution behaviour and potential compatibility with biological environments. Nevertheless, further biological testing will be necessary to determine the material’s prospective regenerative capacities.