Abstract: Objective　To evaluate the cytotoxicity of AlCoCrCuFeTix (x=0,0.25,0.5,1) series high entropy alloys and explore the effect on apoptosis and type I collagen synthesis in L929 Cells by flow cytometry and immunofluorescence. Methods　The AlCoCrCuFeTix (x=0, 0.25, 0.5, 1) series of high entropy alloys were tested by MTT test to evaluate the cytotoxicity of series of alloys. Annexin V-FITC/PI staining with flow cytometry was used to evaluate the effect of series of materials on apoptosis of L929 cells. Immunofluorescence staining was used to detect the level of collagen I synthesis to evaluate the effect of materials on cell proliferation. Results　The cytotoxicity series of high entropy alloys showed an increasing trend with the increase of Ti elements. At the same time, the proliferation rate of L929 cells decreased, the rate of apoptosis increased and the expression level of type I collagen in L929 cells decreased. The metal of AlCoCrCuFe had good cell compatibility, the cytotoxicity was Grade 1 at each time, and there was no statistical difference in the apoptotic rate and type I collagen expression level compared with the blank control group. Conclusions　AlCoCrCuFe alloy in the series of AlCoCrCuFeTix (x=0, 0.25, 0.5, 1) high entropy alloys has good cell compatibility and can preliminarily meet the basic requirements of the application of dental materials.

Key words: high entropy alloy, cytotoxicity, L929 cells, flow cytometry, immunofluorescence