Luteolin-loaded biocomposite containing tantalum and polyimide with antibacterial effect for facilitating osteogenic differentiation and bone-bonding

Polymer-based composites possess some outstanding advantages over ceramic/metallic/polymeric biomaterials, which is considered as a promising candidate for bone repair. Tantalum (Ta)/polyimide (PI) biocomposites (PT) containing Ta nanoparticles of 20 v% (PT20) and 40 v% (PT40) were fabricated, and luteolin (LU) was loaded on PT40 (LUPT40). Compared with PT20 and PI, PT40 with high Ta content displayed high surface behaviors (e.g., roughness, surface energy, and hydrophilicity). PT40 remarkably improved the cell adhesion and multiplication, and LUPT40 with LU displayed further enhancement in vitro. Moreover, LUPT40 obviously boosted osteoblastic differentiation while suppressed the osteoclastic differentiation. Furthermore, LUPT40 exhibited good antibacterial effects because of the slow release of LU. The in vivo results confirmed that PT40 markedly promoted bone-formation, and LUPT40 further enhanced bone-formation/bone-bonding. In short, incorporation of Ta particles improved surface behaviors of PT40, which stimulated cell-response/bone-formation. Moreover, the slow release of LU from LUPT40 not only promoted cell-response/bone-formation but also enhanced bone-bonding. The synergistic effects of Ta and LU release from LUPT40 enhanced bone-formation/bone-bonding. Therefore, LUPT40 would have great potential for repair of bear-loading bone.