Reactive species in non-equilibrium atmospheric-pressure plasmas: Generation, transport, and biological effects

// Dayun Yan 1 , Jonathan H. Sherman 2 and Michael Keidar 1 1 Department of Mechanical and Aerospace Engineering, The George Washington University, NW, Washington, DC, USA 2 Neurological Surgery, The George Washington University, NW, Washington, DC, USA Correspondence to: Dayun Yan, email: // Michael Keidar, email: // Keywords : cold plasma, cancer treatment, reactive species, selectivity Received : September 14, 2016 Accepted : October 29, 2016 Published : November 11, 2016 Abstract Over the past decade, cold atmospheric plasma (CAP), a near room temperature ionized gas has shown its promising application in cancer therapy. Two CAP devices, namely dielectric barrier discharge and plasma jet, show significantly anti-cancer capacity over dozens of cancer cell lines in vitro and several subcutaneous xenograft tumors in vivo. In contrast to conventional anti-cancer approaches and drugs, CAP is a selective anti-cancer treatment modality. Thus far establishing the chemical and molecular mechanism of the anti-cancer capacity of CAP is far from complete. In this review, we provide a comprehensive introduction of the basics of CAP, state of the art research in this field, the primary challenges, and future directions to cancer biologists.

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Cold atmospheric plasma, a novel promising anti-cancer treatment modality.

https://iopscience.iop.org/article/10.1088/0741-3335/59/1/014031/pdf

Plasma medicine—current state of research and medical application

Plasma medicine is a relatively new field that grew from research in application of low-temperature (or cold) atmospheric plasmas in bioengineering. One of the most promising applications of cold atmospheric plasma (CAP) is cancer therapy. Convincing evidence of CAP selectivity towards the cancer cells has been accumulated. This review summarizes the state of the art of this emerging field, presenting various aspects of CAP application in cancer such as the role of reactive species (reactive oxygen and nitrogen), cell cycle modification, in vivo application, CAP interaction with cancer cells in conjunction with nanoparticles, and computational oncology applied to CAP.

https://iopscience.iop.org/article/10.1088/0963-0252/24/3/033001/pdf

Plasma for cancer treatment

Stereolithography is a solid freeform technique (SFF) that was introduced in the late 1980s Although many other techniques have been developed since then, stereolithography remains one of the most powerful and versatile of all SFF techniques It has the highest fabrication accuracy and an increasing number of materials that can be processed is becoming available In this paper we discuss the characteristic features of the stereolithography technique and compare it to other SFF techniques The biomedical applications of stereolithography are reviewed, as well as the biodegradable resin materials that have been developed for use with stereolithography Finally, an overview of the application of stereolithography in preparing porous structures for tissue engineering is given

A review on stereolithography and its applications in biomedical engineering

To date, the significant anti-cancer capacity of cold atmospheric plasma (CAP) on dozens of cancer cell lines has been demonstrated in vitro and in mice models. Conventionally, CAP was directly applied to irradiate cancer cells or tumor tissue. Over past three years, the CAP irradiated media was also found to kill cancer cells as effectively as the direct CAP treatment. As a novel strategy, using the CAP stimulated (CAPs) media has become a promising anti-cancer tool. In this study, we demonstrated several principles to optimize the anti-cancer capacity of the CAPs media on glioblastoma cells and breast cancer cells. Specifically, using larger wells on a multi-well plate, smaller gaps between the plasma source and the media, and smaller media volume enabled us to obtain a stronger anti-cancer CAPs media composition without increasing the treatment time. Furthermore, cysteine was the main target of effective reactive species in the CAPs media. Glioblastoma cells were more resistant to the CAPs media than breast cancer cells. Glioblastoma cells consumed the effective reactive species faster than breast cancer cells did. In contrast to nitric oxide, hydrogen peroxide was more likely to be the effective reactive species.

/pdf/principles-of-using-cold-atmospheric-plasma-stimulated-media-59xfygjuh4.pdf

Principles of using Cold Atmospheric Plasma Stimulated Media for Cancer Treatment.

Cold atmospheric plasma (CAP) has just recently been showing promising anti-cancer activities supported by ability to induce cell death via apoptosis and cell cycle arrest leading to tumor cell destruction in vitro, and in vivo. Several studies showed the ability of CAP-activated media to modulate the tumor cell environment a link between the generation of reactive oxygen species/reactive nitrogen species and cancer cell death following CAP treatment. Targeting cancer cells through ROS-mediated mechanisms has become an attractive strategy for effective and selective cancer treatment by exploiting the aberrant redox characteristics of cancer cells. These effects support the potential direct (CAP) and indirect (CAP-activated media) applications for adjuvant anti-cancer therapeutics, in a combination with the chemo-, radio-, and nano-therapies.

Anti-Cancer Therapies of 21st Century: Novel Approach to Treat Human Cancers Using Cold Atmospheric Plasma

Selectively treating tumor cells is the ongoing challenge of modern cancer therapy. Recently, cold atmospheric plasma (CAP), a near room-temperature ionized gas, has been demonstrated to exhibit selective anticancer behavior. However, the mechanism governing such selectivity is still largely unknown. In this review, the authors first summarize the progress that has been made applying CAP as a selective tool for cancer treatment. Then, the key role of aquaporins in the H2O2 transmembrane diffusion is discussed. Finally, a novel model, based on the expression of aquaporins, is proposed to explain why cancer cells respond to CAP treatment with a greater rise in reactive oxygen species than homologous normal cells. Cancer cells tend to express more aquaporins on their cytoplasmic membranes, which may cause the H2O2 uptake speed in cancer cells to be faster than in normal cells. As a result, CAP treatment kills cancer cells more easily than normal cells. Our preliminary observations indicated that glioblastoma cells consumed H2O2 much faster than did astrocytes in either the CAP-treated or H2O2-rich media, which supported the selective model based on aquaporins.

Dayun Yan

Papers

Cold atmospheric plasma, a novel promising anti-cancer treatment modality.

Principles of using Cold Atmospheric Plasma Stimulated Media for Cancer Treatment.

Anti-Cancer Therapies of 21st Century: Novel Approach to Treat Human Cancers Using Cold Atmospheric Plasma

Toward understanding the selective anticancer capacity of cold atmospheric plasma—A model based on aquaporins (Review)

Plasmas for Treating Cancer: Opportunities for Adaptive and Self-Adaptive Approaches.