Three-dimensional printed sodium alginate clay nanotube composite scaffold for bone regeneration

Nanoparticles can regulate the rheological behavior of polymers during three-dimensional (3D) printing. To overcome the poor molding performance of single sodium alginate (SA), the present study introduced clay halloysite nanotubes (HNTs), and a novel SA/HNT ink with good formability was obtained. Subsequently, a high-performance SA/HNT composite scaffold for bone defect repair was prepared using 3D printing and high-temperature sintering. The rheological properties, interfacial interactions, and mechanical performance of the SA/HNT ink demonstrated hydrogen bonds and electrostatic attractions between SA and the HNTs, and the ink exhibited good shape fidelity, printability, and mechanical properties after 3D printing. The SA/HNTs composite hydrogel scaffold can transfer into a rigid ceramic scaffold after high-temperature treatment at 1200 °C. The cell experiments confirmed that the SA/HNT ceramic scaffold exhibited good biocompatibility and osteogenic activity. In addition, a rat calvarial repair experiment showed that the SA/HNT scaffolds exhibited good bone repair abilities in vivo. Overall, the SA/HNT composite scaffolds have excellent formability, biocompatibility, and osteogenic activity and have broad application prospects in the field of bone defect repair.