Implantable PEKK/tantalum microparticles composite with improved surface performances for regulating cell behaviors, promoting bone formation and osseointegration

Polyetherketoneketone (PEKK) exhibits admirable biocompatibility and mechanical performances but bioinert while tantalum (Ta) possesses excellent osteogenesis and osseointegration but high elastic modulus and density, and processing is too difficult and expensive. In the present study, combining of the advantages of both PEKK and Ta, implantable composites of PEKK/Ta were fabricated by blending PEKK with Ta microparticles of 20 v% (PT20) and 40 v% (PT40) content. In comparison with PT20 and PEKK, the surface hydrophilicity, surface energy, roughness and proteins adsorption as well as mechanical performances of PT40 significantly increased because of the higher Ta particles content in PEKK. Furthermore, PT40 exhibited the mechanical performances (e.g., compressive strength and modulus of elasticity) close to the cortical bone of human. Compared with PT20 and PEKK, PT40 with higher Ta content remarkably enhanced the responses (including adhesion, proliferation and osteogenic differentiation) of MC3T3-E1 cells in vitro. Moreover, PT40 markedly improved bone formation as well as osseointegration in vivo. In short, incorporation of Ta microparticles into PEKK created implantable composites with improved surface performances, which played key roles in stimulating cell responses/bone formation as well as promoting osseointegration. PT40 might have great potential for bear-loading bone substitute.