Study On The Bone Material Modified By Tantalum Implantation And Composite Film Containing Tantalum

Tantalum(Ta),as an ideal new biomaterial,has many advantages,such as excellent corrosion resistance,cytocompatibility,non-stimulation to human tissues and non-toxicity,which has attracted more and more attention in the field of biomedical materials.However,its elastic modulus(greater than 186 GPa)and density(16.6 g/cm~3)are much higher than those of natural bone,which limit its application in clinical.Titanium(Ti-6Al-4V)alloy is widely used as a bone graft substitute in the medical field because of its elastic modulus close to human bone and easy processing into various shapes.However,Ti-6Al-4V also has some disadvantages such as low hardness,diffusion of toxic ions(V⁴⁺and Al³⁺),biological inertia and poor antibacterial performance.Therefore,in this paper,Ta was designed as a modified element to be applied to Ti-6Al-4V to obtain a replacement artificial bone material with good corrosion resistance and biocompatibility.In this paper,Ti-6Al-4V was coated with titanium nitride(Ti N)film to inhibit the release of toxic ions(V⁴⁺and Al³⁺).Then,Ta and Ag ions in different proportions(Ag/Ta=4:1,2:1,1:1)were co-injected into Ti N films by plasma immersion ion implantation system to improve their antibacterial performance and biological activity.The compositions of the samples were analyzed by X-ray photoelectron spectroscopy(XPS).The surface morphology of the sample was observed by scanning electron microscope(SEM).Atomic force microscopy(AFM)was used to observe the roughness of the sample surface,and water contact goniometer was used to observe their hydrophilicities.The adsorption capacities of bovine serum albumin(BSA)were tested by protein adsorption assay.And inductively coupled plasma atomic emission spectrometer(ICP-AES)was used to detect the release of toxic ions.The corrosion resistance of samples was tested by electrochemical workstation.MC3T3-E1 rat osteoblasts and L929 rat fibroblasts were used to study cell proliferation and growth in vitro.Meanwhile,the samples were implanted into rats in vivo,and then the vital organs were sectioned to observe their toxicity.E.coli(ATCC 25922)was used to conduct antibacterial experiments in vitro to test the antibacterial performances of the samples,so as to obtain the best cell activity and antibacterial performance of Ag/Ta-Ti N.The results showed that all Ag/Ta-Ti N samples were non-toxic.And the roughness,hydrophilicity,corrosion resistance,cell activity and antibacterial activity of Ag/Ta-Ti N samples could be effectively improved by adjusting the proportion of Ag/Ta co-implantation.Overall,the results obtained are favorable for its use in orthopedics.In addition,the experimental results based on Ag/Ta ion double implantation titanium nitride(Ti N)film are excellent.In order to simplify the sample preparation process and increase the dosage of Ta,Ti N film is omitted.Moreover,because Cu ion is more widely used in human body than Ag ion,Cu/Ta composite film is used to wrap Ti-6Al-4V.The hardness and elastic modulus were tested by XP nano indentation instrument,and the optimal ratio of Ti-6Al-4V coated by Cu/Ta composite film was explored by water contact angle,ion precipitation,corrosion resistance,cell proliferation and other in vitro experiments,so as to obtain the best performance of composite film.The results showed that the Cu/Ta composite membrane could effectively improve the cell proliferation on the sample surface.And the antibacterial performance of the sample increased gradually with the increase of Cu content on the composite membrane.In summary,the above results can prove that:through modification,metal Ta can be better used as bone replacement material,and better benefit people.