Utilization Of Tantalum,Carbon And Nitrogen Composite Coatings To Improve The Osteogenic Activity Of Titanium Implant

BACKGROUND:Ti6Al4V alloy as an implant material is mostly used in orthopedic and dental fileds.The wide application as standard materials for orthopedic and dental prosthesis due to its excellent biocompatibility,high corrosion resistance,and good mechanical properties.However,it is known that the surface of Ti6Al4 V alloy is generally bioinert,which in turn lead to the instability and aseptic loosening of the implant and result in failure of the implantation.Besides,depoisition a functional coating onto the surface is an important and effective method of surface treatment.Furthermore,an effective bioactive coating on Ti6Al4 V can enhance the biocompatibility,osseointegration and mechanical properties.Recently,transition metal nitrides(TMeN)and carbides(TMeC)coating have been received great attention in the biomedical field.Their excellent properties,including good biocompatibility and osteoinductivity combine with high hardness,corrosion resistance and diffusion barrier,make them very promising candidates for applications in orthopedic and dental field.In particular,transition metal tantalum(Ta)and its oxides or nitrides have attracted considerable attention for their ability to promote cell adhesion proliferation and differentiation.However,the study of tantalum,carbon and nitrogen composite coatings is still blank.OBJECTIVE: Development of tantalum,carbon and nitrogen composite coatings on titanium alloy by magnetron sputtering method and evaluate the biological activity and biocompatibilityMETHODS: We sputtered TaC films and tailored the surface chemical statutes by doped N atom.In the first section: We prepared the TaC coatings,and incorporated N atom to synthesize TaCN coating.We carried out the studies about the evolution of microstructure and the mechanical properties for TaC and TaCN films by employing the X-ray Diffraction(XRD),X-ray Photoelectron Spectroscopy(XPS)and nanoindentor,evaluated the biocompatibility and osteoinduction ability by Rabbit bone marrow stromal cells(r-BMSCs)culture experiments.In the second section: We synthesized the TaN coating with N atoms instead of C atoms,In the experimental part,we characterized the microstructure and the chemical properties the TaN coatings,and evaluated the biocompatibility and osteoinduction ability of the coatings.RESULTS AND CONCLUSION: TaC,TaCN and TaN coatings can promote the early adhesion of r-BMSCs.Cells can grow on the surface of the coating with good morphology.TaCN and TaN coatings perform better in promoting cell proliferation after incorporation of N atoms compared with TaC coatings and TC4(p<0.05).TaC has little effect on osteogenesis.TaCN and TaN promote the deposition of calcium nodules and up-regulate the secretion of ALP,with good osteogenic activity.Based on these results,it is shown that the addition of N atoms further enhances the biocompatibility of the coating and promotes cell proliferation.At the same time,N atoms improve the bioactivity of the coating and promote osteogenic differentiation of bone marrow stem cells.TaC,TaCN and TaN coatings are expected to be used in the field of orthopedic implants.