Cytotoxicity Of Gradient Composite Material Medical Titanium Alloy With Low Elastic Modulus

Objectives MTT method was adopted to observe the effect of gradient composite material medical titanium alloy with low elastic modulus on the morphology and proliferation rate of mouse fibroblast(L929).Flow cytometry was used to detect the effect of gradient composite material medical titanium alloy with low elastic modulus on L929 cells' cycle and apoptosis.The cytotoxicity of this material was explored to provide experimental data for clinical application.Methods The experiment was divided into three parts:1 The experiment was divided into five groups: low elastic modulus medical titanium alloy(new titanium alloy group),low elastic modulus medical titanium alloy by oxidation treatment(oxide layer group),and low elastic modulus medical titanium alloy with tantalum coatings by plasma spraying after oxidation treatment(tantalum coating group),negative control group(RPMI1640 containing 10% fetal bovine serum)and positive control group(volume fraction 0.6% phenol).MTT method was used to test the relative growth rate of L929 cells and evaluate the cytotoxicity in each group.At the same time,the cell morphology was observed under inverted phase contrast microscope.All data were analyzed by statistical software SPSS17.0,and it was statistically significant to set P<0.05 as the difference.2 The experiment was divided into five groups: low elastic modulus medical titanium alloy(new titanium alloy group),low elastic modulus medical titanium alloy by oxidation treatment(oxide layer group),and low elastic modulus medical titanium alloy with tantalum coatings by plasma spraying after oxidation treatment(tantalum coating group),Ti-6Al-4V group(standard control group),negative control group(RPMI1640 containing 10% fetal bovine serum).PI staining was used to detect the changes of cell cycle in each group.All data were analyzed by statistical software SPSS17.0,and it was statistically significant to set P<0.05 as the difference.3 The experiment was divided into five groups: experiment group was the same as experiment 2.Annexin V/PI staining was used to detect apoptosis in each group.All data were analyzed by statistical software SPSS17.0,and it was statistically significant to set P<0.05 as the difference.Results 1 Effect on cell increment: Except for the positive group,L929 cells were normal in morphology and grew well.In the same cultivation period,the optical density values of positive control group was lower than that of other groups,the difference was statistically significant(P<0.05).Except for positive group,the optical density values of other groups increased with the prolongation of cultivation time,the difference was statistically significant(P<0.05).The relative growth rates of new titanium alloy group,oxide layer group and tantalum coating group were greater than 70% of that of negative control group in three periods,and were higher than that of negative control group in 3d and 5d,while the relative growth rate of positive control group was less than 70% of that of negative control group.2 Effect on cell cycle: In the G0/1 phase,cell proportion of new titanium alloy group,oxide layer group and tantalum coating group were lower than that of negative control group,the difference was statistically significant(P<0.05).In the S phase and G2/M phase,cell proportion of new titanium alloy group,oxide layer group and tantalum coating group were higher than that of negative control group,the difference was statistically significant(P<0.05).Cell proportion of tantalum coating group compared with that of Ti-6Al-4V group in the three phases,the difference had no statistical difference(P>0.05).3 Effect on apoptosis: The early apoptosis rate of new titanium alloy group compared with that of negative control group,the difference had no statistical difference(P>0.05).The early apoptosis rate of tantalum coating group and oxide layer group compared with that of Ti-6Al-4V group,the difference had no statistical difference(P>0.05).Conclusions 1 Gradient composite material medical titanium alloy with low elastic modulus has no potential cytotoxicity in vitro,and it can promote cell proliferation to some extent.2 Compared with conventional titanium alloy Ti-6Al-4V,the gradient composite material medical titanium alloy with low elastic modulus had no significant effect on L929 cell cycle and apoptosis.Figure 22;Table 10;Reference 102...