3D-Printed Carbon Scaffolds With Osteoinductivity via Nanotopography-Mediated Mechanotransduction

Osteoinductive biomaterials have emerged as promising platforms for bone regeneration. Nevertheless, conventional calcium phosphate-based systems exhibit suboptimal mechanical properties, particularly under load-bearing conditions, which severely restricts their clinical applicability in critical-sized defect repair. Here, a carbon-based scaffold fabricated through a 3D printing-pyrolysis strategy, featuring osteoinductive coralloid nanostructures on its surface is reported. The scaffold demonstrates a specific strength of 237.5 kN·m kg −1 , surpassing that of commercial orthopedic implants. Notably, the scaffold shows intrinsic osteoinductive properties through successful ectopic bone formation in gluteus maximus, a phenomenon attributed to its nanotopography-mediated activation of mechanotransduction pathways via Yes-associated protein (YAP) nuclear translocation. The scaffold outperformed titanium alloys in repairing both femoral bone defects and cranial bone defects in vivo. Its bone repair efficiency can be further improved by a biomimetic mineralization process. This work highlights the potential of a robust carbon scaffold with a nanostructured surface for osteoinductivity, which will lead to the development of future biomaterials for bone repair.