3D-printed strontium-incorporated β-TCP bioceramic triply periodic minimal surface scaffolds with simultaneous high porosity, enhanced strength, and excellent bioactivity

In bone tissue engineering, scaffolds with excellent mechanical and bioactive properties play prominent roles in space maintaining and bone regeneration, attracting increasingly interests in clinical practice. In this study, strontium-incorporated β-tricalcium phosphate (β-TCP), named Sr-TCP, bioceramic triply periodic minimal surface (TPMS) structured scaffolds were successfully fabricated by digital light processing (DLP)-based 3D printing technique, achieving high porosity, enhanced strength, and excellent bioactivity. The Sr-TCP scaffolds were first characterized by element distribution, macrostructure and microstructure, and mechanical properties. Notably, the compressive strength of the scaffolds reached 1.44 MPa with porosity of 80%, bringing a great mechanical breakthrough to porous scaffolds. Furthermore, the Sr-TCP scaffolds also facilitated osteogenic differentiation of mouse osteoblastic cell line (MC3T3-E1) cells in both gene and protein aspects, verified by alkaline phosphatase (ALP) activity and polymerase chain reaction (PCR) assays. Overall, the 3D-printed Sr-TCP bioceramic TPMS structured scaffolds obtained high porosity, boosted strength, and superior bioactivity at the same time, serving as a promising approach for bone regeneration.