Figure 14: The effects of the exposure time on the viability of RAW 264.7 macrophage cell. Deionized water was exposed to the QELBY ceramic powder for a specified time at room temperature before preparation of DMEM. Cells were seeded in different plates for each exposure time (NE: DMEM was prepared with the water, which was not exposed; EQ: DMEM prepared with the water, which was exposed to QELBY powder for specified times). Data are mean ± SD . Bars with different superscript are significantly different at .