With the use of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide-formazan (MTT-f) production, the cytotoxic effects of single metal ions (Cu2+, Zn2+, Ag+) on HEECs after exposure for 24, 48 or 72 h were investigated, and the synergistic and antagonistic effects of two ions applied simultaneously were also assessed.
The cytotoxicity of the metal ions on HEECs ranked as follows: Ag+>Cu2+>Zn2+. All combinations of those tested indicated that the Cu2++Zn2+ system exhibited an antagonistic effect absolutely, the Zn2++Ag+ system showed both antagonism and slight synergism, and asynergistic effect was observed in the Cu2++Ag+ system.
From a perspective of favorable biocompatibility, Zn2+ and the Cu2++Zn2+ mixture showed evidence of potential components for use in future IUDs. Although having strong cytotoxicity, Ag+ with its low release rate and broad-spectrum antibiotic activity may also be considered. The study also demonstrated the relative stability of Cu2+ as a classic material of IUD.