3D Printing of β-TCP/S53P4 Scaffolds: Physicochemical, Mechanical, and Biological in vitro Evaluation

Abstract

The focus of bone tissue engineering is on the new strategies for developing bioactive and resorbable scaffolds, which have become an alternative to the treatment of bone diseases and trauma. β-tricalcium phosphate (β-TCP) is considered resorbable and has excellent osteoconductivity. In an attempt to achieve good densification of the β-TCP scaffold and improve its biological properties, it arises the possibility of combining this material with S53P4 bioactive glass. Several techniques are used to produce bioceramic scaffolds, among them, direct ink writing (DIW) a type of additive manufacturing based on material extrusion, which allows the production of customized parts, with high complexity and good reproducibility. This work prepared β-TCP and β-TCP/S53P4 (β-TCP/10-S53P4 = 10% wt of S53P4 and β-TCP/20-S53P4 = 20% wt of S53P4) scaffolds by DIW. The ceramic inks showed pseudoplastic behavior and the 3D-printed scaffolds showed similar aspects to the digital model. Also, the β-TCP/S53P4 scaffolds (β-TCP/10-S53P4 = 1.6 ± 0.6 MPa and β-TCP/20-S53P4 = 2.1 ± 0.9 MPa) showed an increase in compressive strength when compared to β-TCP scaffolds (0.9 ± 0.1 MPa). All scaffolds showed apatite-mineralization ability in SBF after soaking for 7 and 14 days, being that the β-TCP/20-S53P4 scaffold showed a higher ability of apatite formation compared to the other scaffolds. Concerning the biological in vitro assays, all the scaffolds showed good cell viability. Thus, the β-TCP/S53P4 scaffolds showed adequate properties which become them, good candidates, to be used in bone tissue engineering.