Electrical conductivity response of liver tissue during irreversible electroporation.

<p>Numerical simulation of the A) electric field and C) electric conductivity distributions during irreversible electroporation procedures with a bipolar probe and an applied voltage of 3000 V. These results employ the B) non-linear electric field dependent liver tissue properties that result immediately after the end of each electroporation pulse and was scaled by 1.25×, 1.50×, and 1.75× in order to study potential organ-to-organ variability (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103083#pone-0103083-t002" target="_blank"><b>Table 2</b></a>).</p

Effect of pulse number on probability of electric damage during irreversible electroporation in liver tissue.

<p>Percentage cell kill due to electroporation after A) thirty, B) fifty, C) seventy, and D) ninety 100-µs pulses using a bipolar probe with an applied voltage of 3000 V. The solid isocontours represents the 50%, 90%, and 99.9% levels from the statistical model of cell kill due to irreversible electroporation, respectively.</p

Physical electrode and mesh visualization for the extremely fine setting used in the numerical modeling software.

<p>Photograph of the physical bipolar electrode (left) and the electrode domain (right) geometry with the corresponding mesh employed in the computational modeling of the bipolar probe used in irreversible electroporation of liver tissue. The points P1, P2, and P3 depict the arbitrary locations at which the temperature was evaluated to determine the length required for thermal equilibration post-treatment.</p

Volumes of cell kill due to irreversible electroporation and thermal damage in liver tissue.

<p>Panel A displays the computed volumes of cell kill due to electroporation and thermal damage for each of the four baseline electrical conductivities investigated. Panels B shows the curves quantifying the ratio of cell kill due to thermal damage and electroporation as a function of conductivity as well. The results in panels A and B were computed during and after the delivery of a ninety 100-µs pulse electroporation protocol with an applied voltage of 3000 V at a pulse repetition frequency of 1 Hz.</p

Effect of pulse number on probability of thermal damage during irreversible electroporation in liver tissue.

<p>Percentage cell kill due to thermal damage after A) thirty, B) fifty, C) seventy, and D) ninety 100-µs pulses using a bipolar probe with an applied voltage of 3000 V. The solid isocontours represents the 50%, 90%, and 99.9% levels from the statistical model of cell kill due to thermal damage, respectively.</p

Probability of cell kill due the cumulative effects of electroporation and thermal damage.

<p>Cell kill due to A) electroporation only, B) thermal damage only, and C) combined damage effects 10 minutes after the completion of the ninety 100-µs pulses delivered at a pulse repetition frequency of 1 Hz. Note: The solid black curves correspond to the 50%, 90%, and 99.9% cell kill isocontours.</p

Statistical model of the probability of cell kill due to pulse number in irreversible electroporation procedures.

<p>The results demonstrate that cell kill due to irreversible electroporation is a function of electric field strength and pulse number as depicted in the 2D contour plot. Note: The data for these plots was adapted from Golberg <i>et al.</i> and demonstrate that there is a minimum electric field and pulse number needed to achieve a 99.9% probability of cell kill due to electroporation <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0103083#pone.0103083-Golberg1" target="_blank">[43]</a>.</p

Immunohistochemical analysis of the tumour vasculature evolution by means of CD 31 staining in LPB tumors after treatment.

<p>A: control; B, C and D: respectively 2, 6 and 24 h after IRE.</p

Spheroid formation images and size quantification.

<p>FSS induces spheroid formation in tumorigenic ovarian cancer cells. (<b>3.1</b>) Images of differential spheroid formation, adherence and outgrowth of benign (MOSE-E, OCE1), tumorigenic (MOSE-L, SKOV-3), and highly aggressive (MOSE-L_TIC<i>v</i>) ovarian cancer cells at 96 h (A-I) and 288 h (time point 3, K-S) in response to FSS. All representative images were taken at the center of the plates. (<b>3.2</b>) the diameter of the formed spheroids were measured and averaged at each time point to monitor growth over time. Significant growth in spheroid diameter was measured in both FSS-exposed MOSE-L cells. In addition, MOSE-L_{TIC<i>v</i>-imm} cells formed large spheroids that grew over time. Note: the MOSE-L_{TIC<i>v</i>-adh} cells re-attached to the culture dishes with an adherent monolayer outgrowth too large to be measured, but the diameters after 288 h are at least 700μm. Asterisks denote statistical significance (t-test, * p< 0.05, ** p< 0.005, and *** p< 0.001).</p

Actin cytoskeleton and focal adhesion organization.

<p>Actin cytoskeleton organization and focal adhesion number and length change significantly in response to FSS exposure. (<b>A</b>) Changes in actin (green) organization in adherent MOSE-E, COE1, MOSE-L, SKOV-3, and MOSE-L_TIC<i>v</i> cells after three, consecutive 96 h exposures to FSS. (<b>B</b>) FSS effects on vinculin-positive focal adhesions. Nuclei are shown in blue. (<b>C</b>) Quantitation of focal adhesion number and size in controls and after FSS exposure. Asterisks denote statistical significance (t-test, * p< 0.05 and *** p< 0.001).</p