Fig. 7 (a) The constructed cellular experimental model. (b) The
cross-sectional distribution of the electric field strength. (c)-(f) he
electric field distribution by various dielectric constant of ceramic
section (100, 1000, 10000, 25000) when AC field with 200 kHz and 5 V is
applied. (g) The percentage of area where electric field distribution is
above 1.5 V/cm by various dielectric constant of ceramic section (100,
1000, 10000, 25000).
Results on Cell
Viability
In order to improve the calculation accuracy of electric field
distribution, we measure the current waveforms during cell experiments
(Fig. 8a) to match the simulation current. The voltage of AC field is 5
V, the experimental current peak could reach to 43 mA. The simulated
current is 40 mA, which is similar with the experimental current. The
simulation shows that the field strength distribution between the two
electrode ranges from 2.0 V/cm to 3.0 V/cm (Fig. 7d). The average
electric field strength is 2.38 V/cm.
Fig. 8b shows the representative U251 cell morphology of the control and
experimental groups at 24 h, and 48 h, after treatment. For control
group, U251 cells shows an elongated morphology at 24 h, which indicates
that U251 cells grow well. For 48 h, U251 cells grow rapidly, compared
with 24 h. For experimental groups, some cells show a round-like
morphology (blue arrow), at 24 h after treatment. Moreover, the cell
density is lower than control group. At 48 h after treatment, more
round-like cells occur on the experimental groups. The cell density is
significantly lower, compared with 48 h control group. Fig. 8c shows the
cell viability at 24 h, and 48 h, after treatment. The cell viability of
experimental group (85.1±5.8%) at 24 h is significantly lower than that
by control group. At 48 h, the cell viability of experimental group
(70.2±4.5%) is further lower that by control group. Figs 8a and 8b show
that the designed high frequency AC generator could inhibit cell
proliferation significantly