Modelling the helium plasma jet delivery of reactive species into a 3D cancer tumour

Abstract

Cold atmospheric plasmas have attracted significant worldwide attention for their potential beneficial effects in cancer therapy. In order to further improve the effectiveness of plasma in cancer therapy, it is important to understand the generation and transport of plasma reactive species into tissue fluids, tissues and cells, and moreover the rates and depths of delivery, particularly across physical barriers such as skin. In this study, helium (He) plasma jet treatment of a 3D cancer tumour, grown on the back of a live mouse, induced apoptosis within the tumour to a depth of 2.8 mm. The He plasma jet was shown to deliver reactive oxygen species through the unbroken skin barrier before penetrating through the entire depth of the tumour. The depth and rate of transport of He plasma jet generated H 2 O 2 , NO 3 − and NO 2 − , as well as aqueous oxygen [O 2 (aq)], was then tracked in an agarose tissue model. This provided an approximation of the H 2 O 2 , NO 3 − , NO 2 − and O 2 (aq) concentrations that might have been generated during the He plasma jet treatment of the 3D tumour. It is proposed that the He plasma jet can induce apoptosis within a tumour by the 'deep' delivery of H 2 O 2 , NO 3 − and NO 2 − coupled with O 2 (aq); the latter raising oxygen tension in hypoxic tissue.

Tailoring the Chemistry of Plasma-Activated Water Using a DC-Pulse-Driven Non-Thermal Atmospheric-Pressure Helium Plasma Jet

“…It is seen that the T v and T r values are similar for the positive and negative pulsed plasma jets and did not significantly vary with pulse width, with values of approximately 0.3 eV and 0.03 eV, respectively. The T v and T r values are higher than we recently measured for similar plasma jet configurations operated with a high-voltage bipolar square wave pulse in two separate studies [34,39]; this is despite a lower applied voltage used in this present study compared to the previous two studies. The reason for the higher T v and T r values in this study is because of an increase in the population of higher energetic electrons with a rapid change in the voltage amplitude.…”

Evaluation of the anticancer effects induced by cold atmospheric plasma in 2D and 3D cell‐culture models

“…On the basis of the comparison between the plasma treatment and H 2 O 2 , NO 2 − , and NO 3 − treatment, the possible anticancer mechanism can be postulated. As shown in Figure e, owing to the protection by the 3D‐organized extracellular matrix and neighboring cells, only long‐lived RONS such as H 2 O 2 , NO 3 − , and NO 2 − may play a key role in plasma‐induced anticancer effects . These long‐lived RONS cross cell membranes by diffusion or through aquaporins and affect A549 cells .…”

Plasma‐activated medium as an innovative anticancer strategy: Insight into its cellular and molecular impact on in vitro leukemia cells

“…[ 66 ] It was recently proposed that CAP can induce apoptosis inside a tumor by the delivery of peroxides and nitrites coupled with aqueous oxygen, which is also responsible for the increase of oxygen tension in the hypoxic tissue. [ 67,68 ] Accordingly, in vivo data showed that a plasma jet source increased both blood flow and tissue oxygen partial pressure. [ 69 ]…”