Two-dimensional concentration distribution of reactive oxygen species transported through a tissue phantom by atmospheric-pressure plasma-jet irradiation

Abstract

The two-dimensional concentration distribution of reactive oxygen species (ROSs) transported through an agarose-film tissue phantom by atmospheric-pressure plasma-jet irradiation is visualized using a KI-starch gel reagent. Oxygen addition to helium enhances ROS transportation through the film. A radial ROS distribution pattern at the plasma-irradiated film surface changes into a doughnut-shaped pattern after passing through the film. The ROS transportation speed is 0.14–0.2 mm/min. We suggest that there are two types of ROS transportation pathways in the plasma-irradiated film: linear and circular. The majority of ROSs are transported through the circular pathway. ROS concentration distributions changed markedly with irradiation distance. Diffusive ROS transportation due to a concentration gradient is negligible in plasma-irradiated films.

Spatial‐temporal distributions of ROS in model tissues treated by a He+O2 plasma jet

“…Similarly, Toshiyuki Kawasaki et al also found a ring‐shaped distribution of ROS on a model tissue, though the model tissue was made of agarose. It was proposed that the center of the ring‐shaped pattern was the point where plasma plume contacted with the model tissue, so the short‐lived species such as O could dye the gelatin gel films by reacting with KI‐starch . This might be the reason for the generation of brown‐dyed point in the center of a ring‐shaped pattern.…”

“…KI‐starch reagent was reported to have color‐forming reactions with ROS via the oxidation of I ‐ to I 2 , and it has been used to visualize the two‐dimensional ROS distribution after passing through a model tissue made of agarose . According to the well‐known iodine‐starch reaction, I ‐ was firstly oxidized to I 2 by ROS, and I 2 reacts with excess I ‐ to form I 3 ‐ then forms complexes with starch, which turns the color to blue.…”

“…The results indicate that plasma can transport several ROS/RNS into the gelatin gel film and the penetration depth increases almost linearly with the treatment time. Also, Toshiyuki et al used a KI‐starch gel reagent to visualize the two‐dimensional distribution of ROS in a model tissue made of agarose . According to the previous studies, the spatial‐temporal distributions of ROS/RNS in biological tissues are much different for different plasmas, and so far much is unknown about the correlation between the plasma parameters and the distributions of ROS/RNS.…”

Shielding‐gas‐controlled atmospheric pressure plasma jets: Optical emission, reactive oxygen species, and the effect on cancer cells

“…Among the species delivered to a target, ROS are widely considered significant players in causing cellular DNA damage, even cell death, and ROS are normally cited as causing increased damage with elevated concentration . Several recent reports have shown an ability to visually determine the 2D ROS concentration on an APPJ‐treated liquid surface by using a potassium iodide (KI)‐starch reagent . Here, with a similar reagent, we quantitatively measured both the 2D distribution of ROS deposited to the liquid surface and the total amount of ROS delivered to the liquid.…”

The assessment of cold atmospheric plasma treatment of DNA in synthetic models of tissue fluid, tissue and cells

“…The mechanism of plasma intervention in biology and medicine is thought to be mainly governed by reactive oxygen species (ROS) and reactive nitrogen species (RNS), or collectively RONS [39][40][41]. Experimentally, using models of tissue fluid, tissue and cells, it has been shown that plasmagenerated RONS are not only delivered into tissue fluid but can also potentially be delivered deep within a tissue mass and across a phospholipid membrane into cells [7,[42][43][44][45][46][47][48][49][50][51][52][53]; computer simulations corroborate these experimental observations [54][55][56][57][58][59][60][61]. In the physiological environment, RONS regulate key biochemical pathways, inducing chemical and physical changes in cells [39,62].…”