Bulletin of the American Physical Society
73rd Annual Gaseous Electronics Virtual Conference
Volume 65, Number 10
Monday–Friday, October 5–9, 2020; Time Zone: Central Daylight Time, USA.
Session PW4: Plasma Biomedicine ILive
|
Hide Abstracts |
Chair: Li Lin, George Washington University |
Wednesday, October 7, 2020 1:00PM - 1:30PM Live |
PW4.00001: Plasma liquid chemistry in the presence of atomic oxygen - implications for plasma medicine Invited Speaker: Katharina Stapelmann Plasma-generated hydroxyl radicals (OH) and oxygen atoms (O) produced by the COST jet, a micro-scaled atmospheric pressure plasma jet, were investigated using a variety of experimental techniques [1]. Several gas admixtures were studied to distinguish the contributions of the two reactive oxygen species (ROS) to chemical modifications, investigated by EPR spectroscopy and an HTA fluorescence assay. Additionally, hydrogen peroxide (H$_{\mathrm{2}}$O$_{\mathrm{2}})$ was quantified in various liquids treated with the COST jet. Large discrepancies in H$_{\mathrm{2}}$O$_{\mathrm{2}}$ formation were observed depending on the treated solution. Reactive species produced in the gas phase were shown to enter the liquid and efficiently react with molecules present in aqueous solution. In particular, molecules present in buffer and cell media widely used in plasma medicine can have a considerable impact on species production in the liquid [2]. Here, the cell culture medium RPMI and the buffer KNO$_{\mathrm{3}}$ are in focus. The difference in H$_{\mathrm{2}}$O$_{\mathrm{2\thinspace }}$production is discussed on a cell culture example [3] and different biological outcomes depending on the used liquid. Furthermore, reaction pathways for the process gases helium, helium with an oxygen admixture, and helium with a water admixture will be discussed, yielding opportunities to tune plasma-induced chemistry to produce desired species. The author would like to thank Brayden Myers, Pietro Ranieri, and Tatyana Smirnova for their contributions. [1] Myers et al., PhysChem ChemPhys, submitted; [2] Bekeschus et al., Scientific reports 7.1 (2017): 1-12.; [3] Ranieri et al., Applied Sciences 10.6 (2020): 2025. [Preview Abstract] |
Wednesday, October 7, 2020 1:30PM - 1:45PM Live |
PW4.00002: Modified GSH embedded in gelatin elucidates the penetration depth of COST-Jet generated reactive species. Pietro Ranieri, Duncan Trosan, Katharina Stapelmann Treatment of biological tissues for cancer treatment and wound healing using non-thermal plasma are limited when considering practical implementation due to the proper `dose' for the application. The correct `dose' is application and plasma source dependent, however the metrics for the proper `dose' are efficacious treatment and limited damage to the tissue. Two major questions required to define the `dose' are: 1) what is the physical penetration depth of plasma-generated species, and 2) what is the penetration depth of the plasma-induced effects? It is established that while plasma species may only penetrate through a fraction of a millimeter, the biological effects are observed up to centimeters into the tissue [1-2]. Several agarose, gelatin, cellular scaffold and spheroid models were developed to answer these questions [3]. In this study, we use a 40{\%} gelatin matrix (for a 60{\%} water content comparable to skin) embedded with glutathione to track the physical penetration of reactive species generated by the COST-Jet. Using 3-D Raman spectroscopy, we observe glutathione modifications in depth as a representation of the physical penetration of reactive species. The COST-Jet was operated under different admixtures to analyze the depth of penetration of different unique chemistries. The resulting Raman spectra will presented. [1] P.Ranieri et al, Plasma Med. 7, 283--297 (2017) [2] A. Lin et al., Oncoimmunology 7.9 (2018) [3] X. Lu et al., Materials Science and Engineering: R: Reports 138, 36-59 (2019) [Preview Abstract] |
Wednesday, October 7, 2020 1:45PM - 2:00PM Live |
PW4.00003: Physical integrity analysis of Personal Protective Equipment (PPE) subjected to surface treatment by corona discharge generated Ozone Md Abdullah Hil Baky, Min Huang, Shariful Islam Bhuiyan, Jamie Kraus, Howard Jemison, David Staack As the search for a vaccine for COVID-19 continues, many countries are still fighting the pandemic with increasing number of patients and deaths. A new challenge amid the effort to check the spread of the disease is shortage of personal protective equipment (PPE). Manufacturers are having hard time coping up with the demands. Therefore, PPEs are being treated with different disinfectants such as UV rays, hydrogen peroxide and ozone etc. Ozone is an effective oxidizer and have been practiced in the industry to kill microorganism. It is recommended that for a 4-log reduction of viral activity, ozone exposure of 40 minutes at 20ppm is required. However, over exposure to ozone might curtail the efficacy and damage the physical integrity of the PPE. In our study we have analyzed the durability of different PPE materials exposed to ozone for a different dose. AAMI gowns were exposed to 1799.4 and 3721.8 ppm-min for hydrostatic pressure testing and only failed at the later test. According to CDC, treated PPEs should be able to withstand a hydrostatic pressure of at least 0.7psi. But 3721.8ppm-min tested gown could hold a hydrostatic pressure of 0.6psi. Samples of AAMI gown and Polypropylene, Polyester, Tyvek Suite materials which make up for the N-95 mask and other PPEs were also treated up to varying ozone dose for wettability testing. No significant change in the water contact angle observed. SEM testing of Polypropylene and Polyester was also performed up-to 1247 ppm-min but no change in structure was noticed. [Preview Abstract] |
Wednesday, October 7, 2020 2:00PM - 2:15PM Live |
PW4.00004: Contribution of single reactive species in plasma liquid chemistry for biomedical approaches Kristian Wende, Sebastian Wenske, Johanna Striesow, Giuliana Bruno, Sander Bekeschus, Michael Lalk, Klaus-Dieter Weltmann, Thomas von Woedtke Plasmas are a new therapeutic option in various inflammatory processes, such as wounds, cancer, and precancerous lesions. Recent studies indicated an interaction of plasma-derived species with cellular redox signaling. Discord exists regarding origin and transport of reactive species while recent publications indicate a mix of contributions from both gas and liquid phase [1]. Using peptides and lipids as targets, significant traces have been identified for atomic and singlet oxygen, hydroxyl radicals, nitric oxide, and peroxynitrite. Among the targets, aromatic structures, double bonds, and thiol groups were found. Introduction of nitrogen from reactive nitrogen species was observed to a limited extent only, with nitrosylation of thiol groups and nitration of phenolic structures most prominent and potentially involved in redox signaling events. A large proportion of the atoms added to the target structures derived from the treated target itself. Taken together, tertiary products assumingly contribute to the biological impact of plasmas. It remains to be clarified, if site and target specific treatment regimens can be utilized to increase the precision of CAP in biomedical applications. [1] K. Wende\textit{ et al.}, \textit{RSC Advances, }vol. 10, no. 20, pp. 11598-11607, 2020, doi: 10.1039/c9ra08745a. [Preview Abstract] |
Wednesday, October 7, 2020 2:15PM - 2:30PM On Demand |
PW4.00005: Atmospheric Pressure Plasma Jet for Dentistry. Loïc Ledernez, Markus Altenburger, Florian Engesser, Gerald Urban, Michael Bergmann What is the lowest common denominator between a root canal treatment, gum disease and periimplantitis? All are bacteria related oral diseases. Bacteria caused the root canal infection, the inflammation of the gum around a natural tooth (periodontitis) and around the dental implant (periimplantitis). The disinfection of the relevant surface is a mandatory step in the treatment of those diseases. The aim of our research project is to establish a method to selectively disinfect the targeted surfaces in situ by means of an electrical plasma jet, without any side effect. Here, we present the development of the plasma-based platform technology that can be applied for the treatment of periimplantitis, periodontitis and in endodontics. We will talk about the plasma source and its normative development, the treatment concept as well as the methodology and analysis of its efficacy. Last but not least, we will show the obtained in-vitro and in-situ results. [Preview Abstract] |
Wednesday, October 7, 2020 2:30PM - 2:45PM |
PW4.00006: On the dose of plasma medicine: Equivalent Total Oxidation Potential (ETOP) XinPei Lu, He Cheng This paper provides a new insight into the fundamentals of plasma medicine: The definition of “plasma dose”. Based on the dominant role of reactive oxygen nitrogen species (RONS) in plasma biological effects, we firstly propose the equivalent total oxidation potential (ETOP), as the definition of plasma dose. The ETOP includes three parts, i.e. the item $H$, which \quad is the equivalent total oxidation potential (ETOP) of the RONS generated by plasma; the item $T$, which \quad is associated with the reactive agents unrelated to RONS, such as UV/VUV emission of plasma; and the item $f(H$,$T)$, which is related the synergistic effects between $H$ and $T $factors. To evaluate the feasibility of the ETOP as plasma dose, the bacterial reduction factor (BRF), which is the log reduction of bacteria colony-forming units (CFU), is selected as the indicator of plasma biological effect. A model establishing the relationship between the ETOP and BRF is presented. For the first try of this paper, linear relationship between the lgETOP and BRF is assumed. The model is initially validated by the published data from literatures. Further simulation and experiment are also conducted, and the positive correlation between the ETOPs and BRFs in the model again suggests that the ETOP could be a reasonable solution as the plasma dose. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700