3D printing of polymer-derived ceramic scaffolds with cuttlebone-like structure for bone repair

Three-dimensional (3D) printed bioceramic scaffolds have been widely used in bone tissue engineering field. However, the porous structure of 3D printed bioceramic scaffolds greatly reduced the mechanical performance, hindering their application in load-bearing sites. Herein, the polymer-derived ceramic (PDC) strategy combined with bioinspired fabrication was proposed to fabricate cuttlebone-like akermanite (PDC/CUTT-AKT) scaffolds with enhanced mechanical strength and biological performance. The PDC/CUTT-AKT scaffolds possessed densified microstructure due to the effect of PDC strategy. Benefiting from the cuttlebone-like macrostructure and densified microstructure, the compressive strength of PDC/CUTT-AKT scaffolds reached 35.80 +/- 2.95 MPa at porosity above 50 %, which is almost two times than those of classical interlock (INT) and octet-truss (OCT) structured scaffolds. Besides, the PDC/CUTT-AKT scaffolds showed lower release rate of bioactive ions and pH values than conventional AKT scaffolds, which was better for in vitro biocompatibility. Moreover, comparing with the scaffolds with classical interlock structure, the PDC/CUTT-AKT scaffolds possessed higher surface and could provide more sufficient area for cell adhesion, proliferation and osteogenic differentiation of bone marrow stem cells. Such PDC/CUTT-AKT scaffold with high strength, high porosity and good biological performance is considered as good candidate for bone tissue repair. This work may provide a potential strategy to fabricate bioceramic scaffold with enhanced mechanical strength for treating load-bearing bone defects.