Nanoscale visualization of the anti-tumor effect of a plasma-activated Ringer's lactate solution.

Plasma-activated Ringer's lactate solutions (PALs), which are Ringer's lactate solutions treated with non-thermal atmospheric-pressure plasma, have an anti-tumor effect and can be used for chemotherapy. As the anti-tumor effect of the PAL is influenced by the cell-treatment time, it is necessary to monitor the structural changes of the cell surface with non-invasive, nanoscale, and time-lapse imaging to understand the anti-tumor effect. In this study, to characterize the anti-tumor effect of the PAL, we used scanning ion conductance microscopy (SICM), using glass nanopipettes as probes, to visualize the structural changes of the cell surface. SICM time-lapse topographic imaging visualized a decrease in the movement of lamellipodia in normal cells and cancer cells after the PAL treatment. Furthermore, in normal cells, protrusive structures were observed on the cell surface. Time-lapse imaging using SICM allowed us to characterize the differences in the morphological changes between the normal and cancer cells upon exposure to the PAL.