Effect Of Niobium Content On The Mechanical Property And Biocompatibility Of Porous Titanium-Niobium Alloy

Objective:To investigate the effect of Niobium(Nb) content on the mechanical property and biocompatibility of porous Titanium-Niobium(Ti-Nb) alloy,in order to provide basic experimental basis for further research of porous titanium-niobium alloy artificial joint and other orthopaedics implant materials.Methods:1.Five groups of porous metal specimens with porosity of 70% were prepared by powder metallurgy method:pure Ti;pure Nb;Ti30Nb;Ti50Nb;Ti70Nb。2.Mechanical properties test :pore size, porosity, compressive strength and elastic modulus were measured and compared for the specimen of each groups respectively.3.In vitro test:human osteosarcoma cell line(Saos-2)were inoculated on each metal specimen group in 24-well plates, cells were collected at different time points to conduct cell adhesion, cell proliferation, alkaline phosphatase activity assay, osteocalcin quantitative detection experiments.Using the SPSS18.0 software package for statistical analysis,and measurement data were expressed as mean ±standard deviation,each index of the group at the same time were compared by using analysis of variance between groups.Results: The pore size of porous metal of each groups distribute in the range of 100-500μm,80% of which distribute in the range of 200-400μm.The porosity of each groups’ specimen were about 70%.The pore distributed uniformly with 3-D Interconnected;2.The elastic modulus and compressive strength of porous metal decreases with increasing Nb doping amount;3.The cell adhesion test showed:the 4th hours five sample number had no statistically significant difference.(F=3.075,P=0.068>0.05);There is statistically significant difference between five samples at 24 th hours(F=21.235, P=0.000 < 0.05),cell adhesion of pure Ti group was the most,and Ti70 Nb was the least,and the difference between three Ti-Nb alloy groups was not significant;4.Cell proliferation test showed :the 1st day and 10 th day had seemed no significant difference between all groups,there were significant difference between groups at the 3rd and 7th day,the Nb group with the highest proliferation,followed by blank control group,Ti70 Nb.pure Ti group was the least.(1d:F=1.023 P=0.446;3d:F=32.590 P=0.000;7d:F=79.684 P=0.000;10d:F=0.550 P=0.736)5.Alkaline phosphatase activity assay showed :the tested ALP activity of three Ti-Nb alloy groups were all significantly higher than pure Ti and Nb at the 7th,10 th,14th and 21 st day.Ti70 Nb group with the highest value.6.Osteocalcin quantitative detection experiments showed :the tested osteocalcin of three Ti-Nb alloy groups were all significantly higher than pure Ti and Nb at the 7th,10 th,14th and 21 st day.Ti70 Nb group with the highest value again.(7d F=48.080 P=0.000;10d:F=141.091 P=0.000;14d:F=138.207 P=0.000;21d:F=149.579 P=0.000)Conclusion:1.The elastic modulus and compressive strength of porous metal decreases with increasing Nb doping amount;2.The porous titanium-niobium alloy induces the Sa OS-2 cell adhesion, proliferation and differentiation, which is stronger than that of the porous pure titanium and the porous pure niobium.For cell adhesion and differentiation, with the increase of the content of niobium, the promoting effect is enhanced.