3D-printed porous PEI/TCP composite scaffolds loaded with graphdiyne oxide on the surface for bone defect repair and near-infrared light-responsive antibacterial

Bone implants that promote osseointegration and have antimicrobial capabilities are necessary to ensure optimal long-term functionality of implants. In this study, a porous composite osteogenic scaffold was prepared using a twin-screw extruder and a fused deposition modeling three-dimensional (3D) printer. A polydopamine (PDA) coating was used to load graphdiyne oxide (GDYO) on the surface of the 3D printed polyetherimide-tricalcium phosphate (PEI-TCP) osteogenic scaffold through 7C-7C double-bond interactions. The resulting P-T-GDYO composite scaffold was characterized, and its mechanical properties, ability to promote osteogenic differentiation, and light-responsive antibacterial activity were evaluated. When the scaffold was doped with 10 wt% beta-TCP, its mechanical properties remained in the range of those of cancellous bone. In terms of osteogenic differentiation, the P-T-GDYO composite scaffold promoted adhesion and osteogenic differentiation of MC3T3-E1 cells, as well as effectively promoting endogenous bone regeneration of rabbit femoral condyle bone defects in osteogenesis experiments in vivo. In a mouse subcutaneous infection model, after near-infrared light irradiation, P-T-GDYO showed an antibacterial rate of 90.18 % against Staphylococcus aureus, while maintaining good tissue-organ compatibility. This study represents an important development in GDYO-based photothermal antibacterial materials in the field of orthopedics and expands its application in the biomedical field.