Three-dimensional printing of cerium-incorporated mesoporous calcium-silicate scaffolds for bone repair

In the study, we developed hierarchical composite scaffolds by 3D printing technique with mesoporous CaSiO₃ containing controlled amounts of Ce substitution in Ca–Si system. The scaffolds were porous with 3D interconnected large pores (size ~400 μm) and an overall porosity above 70 %, combined with a relative high compressive strength (~7 MPa). These properties are essential for enhancing bone ingrowth in tissue engineering. The in vitro biological properties of apatite formation, cell proliferation, and differentiation were characterized on CeO₂-MCS scaffolds and MCS scaffolds. Results indicated that CeO₂-MCS scaffolds induced similar apatite deposition and cell attachment of human bone marrow stromal cells. In addition, CeO₂-MCS scaffolds enhanced expression of alkaline phosphatase, osteogenesis genes (bone morphogenetic protein-2, collagen type I), and angiogenesis gene markers (fibroblast growth factor and vascular endothelial growth factor), compared to that for MCS scaffolds. Therefore, the 3D-printed CeO₂-MCS scaffolds showed the potential of enhanced osteogenic activity.