Macrophage responses to a Zr-based bulk metallic glass.

Bulk metallic glasses (BMGs) are considered to be a competitive candidate of biomedical materials, owing to their appealing mechanical properties and high thermal processability. Based on the established biosafety of the Zr-based BMGs, macrophage responses to (Zr₅₅ Al₁₀ Ni₅ Cu₃₀)₉₉ Y₁ (atomic percent) BMG were investigated in the present study, in comparison with Ti-6Al-4V alloy. The adhesion of RAW 264.7 macrophages to both alloys was found to be mediated by protein adsorption. The Zr-based BMG is capable of supporting regular adhesion and proliferation of macrophages, indicating its good biocompatibility, which agrees with previous findings using other mammalian cells. A lower degree of morphological activation was revealed on Zr-based BMG substrates than on Ti-6Al-4V substrates, which is evidenced by smaller spreading areas and less ruffling on cell surfaces. Smaller amount of proinflammatory cytokine, tumor necrosis factor-alpha, was secreted by macrophages cultured on Zr-based BMGs, which further confirms the lower level of inflammation induced by BMG than by Ti alloys.