Improving the mechanical performance of porous ice-templated bioactive scaffolds through the incorporation of additively manufactured reinforcement frames

The combination of ice-templating and 3D printing represents a promising strategy for the fabrication of robust bioactive scaffolds with multi-scale porosity. The ice-templated microconstituent provides a highly porous heterogeneous environment for cells, while the additively manufactured component serves to mechanically reinforce this porous substrate while occupying minimal space within the resulting composite. Different minimal surface reinforcement structures were obtained by DLP using highly loaded photosensitive suspensions of β-TCP and subsequently infiltrated with aqueous suspensions of the same material. The compressive strength of the reinforced structures improved over 500 %, compared to the ice-templated structures, with Weibull distribution central values of 12.2 ± 1.1 MPa and 2.2 ± 1.1 MPa, respectively. This was accompanied by a significant improvement in their reliability, roughly quintupling their Weibull modulus. Preliminary in vitro tests showed that none of the samples exhibited significant toxicity to MC3T3 cells after cultivation and cell anchorage was observed onto their surfaces.