Figure 11.

Some bubbles can be pressed back into U87MG cells in Milli-Q water. (a) A schematic illustration of the protocols. (b) The growth of bubbles in DMEM after the CAP treatment. (c) The cellular response when the cells with bubbles were immersed in Milli-Q water. 6 mL cell solution was cultured in a 60 mm dish with a density of 7.5 × 10⁴ cells/mL for one day before the treatment. For the control group, the medium was also renewed. No CAP treatment was performed before imaging. The bubbling on U87MG cells was first generated after a direct 2 min of CAP treatment. 8 min of the bubbling process was further recorded when the cells were immersed in DMEM. Afterward, DMEM was quickly (< 1 min) removed and renewed by 6 mL of Milli-Q water. The change of bubbles was recorded following this step. ‘ + x min’ means the photo was taken x min after the treatment or after cells were immersed in Milli-Q water. In the second row, specific bubbles were marked by specific colors. The scale bar was 50 μm (black). In each row, the photos after the treatment were taken in situ. All photos were taken by using a Nikon TS100 inverted phase-contrast microscope.