Effect of SiO 2 on SiO 2 /HA/TCP Porous Composite Scaffolds for Bone Tissue Engineering by 3D Printing

ABSTRACT In this study, SiO 2 /hydroxyapatite (HA)/tricalcium phosphate (TCP) porous composite scaffolds were successfully prepared by three‐dimensional printing (3DP). The rheological properties of the printing slurries and the characteristics of the composite scaffolds were investigated. The results showed that the viscosities of the printing slurries with different SiO 2 contents were respectively 16.3, 16.7, 44.3, and 78.5 Pa·s at shear rates of 38.3, 46.4, 35.9, and 33.0 s −1 , which was suitable for printing. The porosities of printed porous composite scaffolds with different SiO 2 contents were about 58% and their compressive strengths were respectively 16.4, 20.8, 41.4, and 25.4 MPa after sintering at 1200°C, which indicates that the appropriate addition of SiO 2 can enhance the strength of the composite scaffolds. In vitro immersion experiments showed that the porous composite scaffolds with different SiO 2 contents exhibited respectively the weight loss rate of 8.7%, 9.0%, 9.6%, and 7.6% and pH values of the solutions remained within the range of 7.2–7.45 after 56 days in simulated body fluid (SBF), which is suitable for bone repairing.