Mechanical Properties And Osseointegration Evaluation Of Tantalum Nanoparticles Reinforced Polyetheretherketone

ObjectivePolyetheretherketone(PEEK)has been used in orthopedic surgery due to its biocompatibility.However,as a bioinert material,direct osseointegration can hardly be formed between PEEK and bone tissue.Thus,numerous methods are widely studied to alter the bioactivity of PEEK.Tantalum(Ta),as a promising metal,has been broadly applied in orthopedic area for implant fabrication,which provides satisfying osseointegration outcomes.The aim of the study is to combine the advantages of tantalum and PEEK by adding tantalum nanoparticles to PEEK in order to increase both the mechanical properties and bioactivity,providing a potential new composite biomaterial for orthopedic use.Multiple compositions of tantalum nanoparticles reinforced polyetheretherketone(Ta-PEEK)materials were fabricated.The mechanical properties as well as the biological features on MC3T3-E1 cells and in vivo osseointegration effects were studied.MethodsMultiple compositions of tantalum nanoparticles reinforced polyetheretherketone(Ta-PEEK)materials(mass fraction of tantalum ranging from 1%to 9%,namely1%Ta-PEEK,3%Ta-PEEK,5%Ta-PEEK,7%Ta-PEEK and 9%Ta-PEEK)were fabricated via ball-milling and heat-compressing molding.Methods including scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),profilometer,contact angle,mechanical tests,Fourier transform infrared spectrometer(FTIR),thermogravimetric analysis(TGA),and differential scanning calorimeter(DSC)were used for characterization.Biological functions in vitro as cytotoxicity,attachment,collagen secretion,biomineralization and gene expression were then investigated.Samples were further implanted to Sprague Dawley rats for osseointegration evaluation.ResultsTantalum nanoparticles were successfully incorporated into PEEK material proved by SEM and EDS.No difference was observed in contact angle and surface roughness parameters among different groups.The highest elastic modulus and compressing strength were observed in 3%Ta-PEEK.Lowest glass transition temperature(T_g),crystallization temperature(T_c),melting temperature(T_m)and delta capacity(?Cp)were detected in3%Ta-PEEK,while melting enthalpy(H_m)and crystallization degree were lowest in5%Ta-PEEK.Cell experiments as cell adhesion,collagen secretion,biomineralization and osteogenesis-related gene expression showed preferable results in 3%Ta-PEEK and5%Ta-PEEK.Improved bone integration was shown in 3%Ta-PEEK and 5%Ta-PEEK in vivo.ConclusionEnhanced mechanical properties were detected in 3%Ta-PEEK while promoted bone formation was proved for 3%Ta-PEEK and 5%Ta-PEEK compared to others groups both in vivo and in vitro,suggesting that the addition of tantalum nanoparticles modified the osseointegration ability of PEEK.The combination of these two materials has a large clinical potential for orthopedic implants.