3D printing of methacrylated hyaluronic acid/α-TCP composite scaffold for bone defect repair

Bone defects can occur due to various reasons, such as trauma, infection, congenital disorders, or surgical interventions like tumor removal. This study presents the development and characterization of a novel 3D printable composite ink integrating α-tricalcium phosphate (α-TCP) with a photocuring polymer hyaluronic acid methacrylyol (HAMA) for bone defect repair. The composite bioink was formulated to address the limitations of traditional bioinks and to harness the benefits of α-TCP's osteoconductivity and the mechanical stability provided by photocuring polymers. The resulting HAMA/α-TCP scaffolds were evaluated for their rheological properties, biocompatibility, mechanical strength, and osteogenic potential both <i>in vitro</i> and <i>in vivo</i>. The study demonstrated that the incorporation of α-TCP into the HAMA matrix significantly enhanced the scaffold's mechanical properties and osteogenic differentiation capacity. <i>In vivo</i> studies using a rat skull defect model confirmed the superior bone regenerative potential of the HAMA/α-TCP scaffolds compared to controls. The findings suggest that the HAMA/α-TCP composite scaffolds offer a promising approach for bone defect repair, highlighting their potential for clinical translation in orthopedic applications.