Cryogenic 3D printing of multifunctional chitosan/La-doped hydroxyapatite nanowires porous bone scaffolds with enhanced osteogenesis

Lanthanum-doped hydroxyapatite nanowires (La-HAW) were successfully synthesized via a hydrothermal method and integrated into cryogenically 3D-printed chitosan (CS) porous scaffolds. Owing to their enhanced osteogenic activity and inherent antibacterial properties, these scaffolds represent a promising strategy for bone tissue engineering applications. Comprehensive characterization confirmed that the La-HAW possessed high aspect ratios (>1000), uniform elemental distribution, and successful incorporation of La 3+ into the hydroxyapatite lattice via XRD, XPS, and EDS analyses. In vitro biological evaluations revealed that La-HAW significantly promoted the osteogenic differentiation of MC3T3-E1 pre-osteoblasts, evidenced by elevated alkaline phosphatase (ALP) activity and enhanced calcium mineralization, while maintaining excellent biocompatibility. Additionally, La-HAW exhibited strong antibacterial efficacy, with inhibition rates of 90 ± 2% against Escherichia coli and 78 ± 3% against Staphylococcus aureus . When structured into porous chitosan-based scaffolds via cryogenic 3D printing, the resulting CS/La-HAW scaffolds exhibited hierarchical porosity with favorable degradation kinetics, high swelling capacity, and improved cellular adhesion and proliferation. The unique nanowire morphology provided abundant anchoring sites that promoted cell adhesion, spreading, and cytoskeletal extension, synergistically enhancing osteogenic induction. These findings highlight the dual-functional capability of La-HAW based scaffolds, combining enhanced osteogenesis with inherent antibacterial properties, positioning them as a promising platform for bone regeneration.