Study On Biosafety Of Titanium-tantalum Biological Gradient Composites

Objectives To detect the cytotoxicity of different concentrations of extracts of new Titanium-tantalum(Ti-Ta)biological gradient composites on L929 cells in mice by MTT assay,and to evaluate the biological safety of the new composites by flow cytometry,so as to provide experimental basis for their future clinical application.Methods The experimental study was divided into three parts: 1 A novel Ti-Ta biogradient composite was prepared by hydrothermal-plasma spraying gradient treatment of tantalum coating in College of Materials,North China University of Technology,and the effect of the new composite on L929 cytotoxicity was detected by MTT method.The experiment was divided into five groups: pure titanium group(group A),hydrothermal treatment group(group B),tantalum coating group(group C).The RPMI1640 medium containing 10% fetal bovine serum was used as negative control group(group D),and the complete medium containing 0.64% phenol was used as positive control group(group E).The absorbance value(OD value)of cells cultured in the extracts of each experimental group was determined by MTT method after 1,3 and 5 days.The relative cell increment rate(RGR)was calculated and the toxicity grading of each group was evaluated.2 Effect of new Ti-Ta biogradient composites on cell cycle of L929 cells.The experiment was divided into four groups: pure titanium group,hydrothermal treatment group,tantalum coating group and negative control group.The L929 cells were cultured in the extracts of each experimental group for 48 hours and then stained with PI.The changes of cell cycle were detected by flow cytometry after the intervention of extracts of different materials.3 The effect of new Ti-Ta biogradient composites on apoptosis of L929 cells.The experiment was divided into four groups: pure titanium group,hydrothermal treatment group,tantalum coating group and negative control group.L929 cells were cultured with extracts of each experimental group for 48 hours and stained with Annexin V/PI staining.The apoptotic status of L929 cells in each group was observed by flow cytometry.Results 1 The new Ti-Ta biogradient composites were observed by scanning electron microscopy to have a uniform and dense structure,a rough texture on the surface,no obvious cracks,and a tantalum particle that melted into a spherical shape in the surface porous structure.2 MTT assay for cytotoxicity results: The absorbance values of the 100%tantalum coating group were higher than those of the negative control group(P<0.05).The absorbance values of the negative control group and the experimental group were related to the culture time.The difference was statistically significant(P<0.05),but there was no significant difference in the absorbance values between the positive control group and the control group(P>0.05).In the same time period,the positive control group compared with the experimental group.The values were significantly different,and the difference was statistically significant(P<0.05).3 PI method for detecting cell cycle results: G1 phase:There was statistical difference between the tantalum coating group and the other two experimental groups(P<0.05),and there was no statistical difference compared with the negative control group(P>0.05);Period: There was significant difference between the pure titanium group and the hydrothermal treatment group and the negative control group(P<0.05).There was no significant difference between the tantalum coating group and the negative control group(P>0.05);G2 stage: pure titanium There was no significant difference between the group and the negative control group(P>0.05).There was significant difference between the hydrothermal treatment group and the tantalum coatinggroup compared with the negative control group(P<0.05).4 Annexin V/PI double staining method for detecting apoptosis results: There was statistical difference between the experimental groups and the negative control group(P<0.05).The hydrothermal treatment group and the tantalum coating group were statistically compared with the pure titanium group(P<0.05).Conclusions 1 The new Ti-Ta biological gradient composites has no short-term cytotoxicity in the in vitro cytotoxicity test,and it promotes cell proliferation to a certain extent compared with pure titanium material.2 Compared with pure titanium materials,the new composite materials have a certain promoting effect on the cell cycle of L929.3Compared with pure titanium materials,the new composite materials have less effect on the apoptosis of L929 cells.Figure20;Table11;Reference 84...