Niobium carbide-functionalized polylactic acid bone scaffold with near-infrared light-mediated shape memory and photothermal therapy for complex bone defects.

Complex bone defects, especially irregularly shaped ones, pose a significant challenge in bone tissue engineering. Bone scaffolds require not only a well-designed porous structure, appropriate mechanical properties, and biocompatibility but also effective photothermal therapy and enhanced shape adaptability. This study proposes a photothermal-functionalized polylactic acid/polyethylene glycol/niobium carbide nanoparticles (PLA/PEG/NbC) nanocomposite bone scaffold with antitumor and shape memory capabilities. The 3D-printed scaffold exhibits a periodically ordered porous structure and mechanical properties dependent on material composition. It shows exceptional photothermal responsiveness, with its steady-state temperature range modulated by adjusting material composition and NIR light parameters. The scaffold demonstrates excellent contactless photothermal shape memory recovery, offering potential for minimally invasive implantation. It also shows significant photothermal suppression effects on HOS osteosarcoma cells, achieving a 90 % suppression rate. Biological experiments reveal favorable degradation behavior due to PEG, enhanced biomineralization capacity, and promoted proliferation and osteogenic differentiation of MC3T3-E1 cells, which are attributed to NbC and PEG. This functional bone scaffold integrating photothermal-responsive mediated shape memory and tumor suppression functionality offers a promising solution for addressing irregular-shaped bone defects and tumor-associated bone defects.