Mesoporous calcium silicate and titanium composite scaffolds via 3D-printing for improved properties in bone repair

Calcium silicate (CS) composite bone tissue engineering scaffolds were three-dimensionally printed using titanium metallic powders as the second strengthening phase for overcoming the inherent brittleness and fast degradability. In order to promote the sintering process of all composite scaffolds, mesoporous structure was further introduced into sol-gel-derived CS powders obtaining mesoporous CS (MCS) with larger surface area. The influences of mesoporous structure, sintering temperature and Ti content have been investigated through comparisons of the final scaffold composition, microstructure, compressive strength and in vitro stability. Results showed that CS matrix materials reacted with Ti could form less degradable CaTiO3 and TiC ceramic phases under 1200 °C sintering. The MCS-Ti scaffolds presented significantly improved density and homogeneity compared to CS-Ti. Therefore, MCS-Ti3 scaffolds with the highest 30% Ti addition, possessed the biggest compressive strength of 4.11 ± 0.39 MPa. Moreover, in vitro degradation analyzations demonstrated that MCS-Ti scaffolds enhanced ability of control over the weight losses and pH values of surrounding medium, indicating promising use as an alternative composite for bone repair.