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.

A microporous surface containing Si3N4/Ta microparticles of PEKK exhibits both antibacterial and osteogenic activity for inducing cellular response and improving osseointegration

As an implantable biomaterial,polyetherketoneketone(PEKK)exhibits good mechanical strength but it is biologically inert while tantalum(Ta)possesses outstanding osteogenic bioactivity but has a high density and elastic modulus.Also,silicon nitride(SN)has osteogenic and antibacterial activity.In this study,a microporous surface containing both SN and Ta microparticles on PEKK(STP)exhibiting excellent osteogenic and antibacterial activity was created by sulfonation.Compared with sulfonated PEKK(SPK)without microparticles,the surface properties(roughness,surface energy,hydrophilicity and protein adsorption)of STP significantly increased due to the SN and Ta particles presence on the microporous surface.In addition,STP also exhibited outstanding antibacterial activity,which inhibited bacterial growth in vitro and prevented bacterial infection in vivo because of the presence of SN particles.Moreover,the microporous surface of STP containing both SN and Ta particles remarkably induced response(e.g.,proliferation and differentiation)of rat bone mesenchymal stem(rBMS)cells in vitro.Furthermore,STP significantly improved new bone regeneration and osseointegration in vivo.Regarding the induction of cellular response in vitro and improvement of osseointegration in vivo,the microporous surface containing Ta was better than the surface with SN particles.In conclusion,STP with optimized surface properties activated cellular responses in vitro,enhanced osseointegration and prevented infection in vivo.Therefore,STP possessed the dual biofunctions of excellent osteogenic and antibacterial activity,showing great potential as a bone substitute.