SYNOPSIS
In general, cell viability decreases as the concentration of chemicals increases. However, the survival rates of cells exposed to trace amounts of chemicals increases in many cases. Few reports have been published on such phenomenon. In addition, cells damaged by chemical exposure are known to recover when the chemicals are washed away and the medium is replaced with fresh medium. The relationship between the increased cell viability and the cell recovery rates after exposure to trace amounts chemicals remain unclear.
In the present study, a three-dimensional culture with collagen gel was employed to examine the cell viability rates by exposing cells to copper, silver, tin, and zinc solutions at low concentrations. In addition, the collagen gel containing cells was vertically cut to examine the decreased cell recovery rates of the cut surface after 7 days of culture based on the amount of dye penetration. As a result, the cell survival rates increased by a trace amount of zinc ion, with the highest cell recovery rate. Also, the cell survival rates were slightly increased by exposing the cells to trace amounts of other metal ions. These results may provide useful basic data for applying metal ions to regenerative medicine in the future.

Key words: cell recovery, cell viability, IC50, cytotoxicity, metal ions