Magesh Thiyagarajan

Magesh Thiyagarajan is a Sigma Xi member who is an associate professor of engineering at Texas A&M University-Corpus Christi. He joined Sigma Xi in 2008. 

In this video, he discusses how cold plasma has applications for cancer treatment, wound healing, and food sterilization. He gives demonstrations of cold plasma devices and talks about his research on laser-induced plasma.

Transcript from Video

Heather Thorstensen: Hi, I’m Heather Thorstensen, manager of communications for Sigma Xi, The Scientific Research Society. Today, for our Meet Your Fellow Companion series I’m going to be talking with Sigma Xi member Magesh Thiyagarajan.

Magesh is an associate professor of engineering at Texas A&M University-Corpus Christi. He is the director of the university’s Plasma Engineering Research Lab, and he leads research involving cold plasma.

Magesh, thanks for joining me.

Magesh Thiyagarajan: Hi, thank you.

Can you start by explaining what cold plasma is?

Sure. Cold plasma is nothing but plasma in near-room temperature. Plasma itself is nothing but an ionized form of a gas. We traditionally know the three phases of matter: solid, liquid, and gas, based on how much energy that you feed into it. And when we add more energy to gas, they reach an excited state and from there it reaches an ionized state. So plasma, it’s a collection of ionized particles, such as electrons, ions, and some of the gas particles itself. It’s very similar to the blood plasma, that’s why the name itself is derived from it. It’s a mixture of ions and electrons in a cloud of gas, similar to what you have on blood plasma— white cells, red blood cells in a plasma medium. So when we make plasmas in room temperature, the name is called cold plasma.

One of the projects that you’re working on with cold plasma is to fight cancer. Can you talk about how cold plasma is used to fight cancer?

Working on cold plasmas for cancer research has been one of the recent initiatives. We had been working on cold plasma and seeing their biochemical properties on working with microorganisms and so on. We’ve also been very aware that the cold plasma produces reactive species [the reactive species include an array of species such as, excited and ionized atoms, hydroxyl, reactive nitrogen and oxygen species, etc. It can change based on the working gas that is being used.] So, while exploring the cancer research we found that some of the cancer cells, they actually require these reactive species for them to go through a self-induced death process, we call it apoptosis. That process itself requires an external supply of an environment with the reactive species. And surprisingly the cold plasmas can produce the same type of reactive species. So when we explored it, we actually found that with a certain amount of plasma exposure, or a certain amount of reactive species exposure, the cancer cells can actually choose to go through an apoptotic method and when we have, of course, prolonged exposure or overexposure, the cancer cells go through necrotic process, which is a sudden destruction of cell structure. So cold plasma research, we explored it on the cancer cell and we observed with a certain type of plasma exposure we could induce an apoptotic process in these cancer cells.

And another medical application that you’re working on is infections with cold plasma. How are infections and cold plasma related?

So the infections can get worse or it can be prolonged based on the bacteria that can be present on the open wounds as well as the tissues that were being damaged over the infection area, it could take a longer time. It also requires a similar reactive species that the body itself generates for healing purposes. When the cold plasmas, which produce a similar reactive species, is supplied externally around the wounds, it does two things. One is it sterilizes the area by killing any potential bacteria that may be present which could actually further worsen the wound. So when we clear the area with cold plasmas, then the cold plasma-supplied reactive species also aides the wound to accelerate the healing process by absorbing the externally supplied reactive species and it also triggers some other biochemical reactions for these cells to send signals for asking for more species for tissue repair. So that project is a very new initiative and we are still beginning to work on it and there is a long way to go on the wound healing project.

What would be some of the benefits of treating cancer or treating infections with cold plasma rather than treating them with more traditional methods?

That’s a very good question. For cancer treatment, it’s a new exploratory field. It could be an alternative technology or it could be used as a supplementary technology, or complementary in addition to the existing technologies. One challenge with the existing technologies still today is the severity of the treatment itself, such as the radiation and chemotherapy. It can be very harsh on the patients due to the overexposure or full exposure of the human body. With respect to plasmas, they are less radiation, or in fact it doesn’t have radiation for the overexposure of the entire body, for example. So if you have a localized treatment, skin cancer or tumors, you can have it treated very locally, still inducing them through drugs or radiation therapies. [However, cold plasma is] more localized and it doesn’t expose the [other] tissues or the [overall] body itself, where you impact lots of healthy cells through the treatment.

And in respect to the wound healing, it’s very similar. Instead of taking drugs and exposing your entire body to it, and experience more side effects because of the treatment, you’re looking at more localized area of treatment. And this is something that you can imagine as a hand-held device or portable, enough that you can operate it at home instead of having the treatment done at a hospital or center. So there are scientific as well as the benefits of inducers as well, using the cold plasma technology.

Can you show us a little bit about what a cancer-fighting cold plasma device might look like? And I know other researchers are working on cold plasmas with cancer so I’d like to know the unique part about your project.

What we develop is cold plasmas in atmospheric air and we also use some of the noble gases. The equipment itself that we use, we have developed a number of different cold plasma technologies, but principally based on the cold plasma principle. Some may look like plasma needles, some may look like plasma shower. We have one here that we modified I can show [gets device]. It’s a probe and it has, as you can see, it has a number of openings from which an array of cold plasma would propagate out of the surface and we usually have it upside down. And when we have the cancer cells exposed to it underneath, with our cancer cell lines, we keep them for anywhere between a few seconds to a couple of minutes for calibrating an array of plasma dosages.

The unique part of our research is we develop cold plasmas with atmospheric air so it doesn’t require an additional supply of gases as an operating supply. And also we try to make it as portable as possible for other military-related applications.

I wanted to ask you about the portable devices because I know that’s a project that you have received funding for from the Department of Defense and I wondered what is the main goal of having a portable cold plasma device and what are the special considerations involved in making something like that.

That’s a good question. As you said, there has been growing interest on this cold plasma area and the potential for wide ranges of biomedical applications, let it be wound healing or infection treatment or sterilization. So there has been a great interest in public as well as in government aspects. However, traditionally the plasmas, or the prototypes or the hardware required to make plasmas, are traditionally bulky and huge. It would require supply of gases and power supplies. And the arrangement itself would be usually large in size. So the military, or the Department of Defense, was interested in the possibility of using such a technology for assisting soldiers or in distant locations—and there have been several incidents for infections through wounds or sometimes when they have catheters being used for treatments, and they actually infect those wounded areas. So there has been a need for distant applications, remote applications, for cold plasma for disinfection applications. So the military, the Department of Defense, was interested in developing a portable type of plasma source where you can have it in your backpack or something like a handheld device, where you could have it battery-operated in an ambulance setup, where you could have it used for initial treatments for disinfection or treatment of that sort. So we develop a range of plasma devices through the support of Department of Defense funding.

And food sterilization is another area that you’re working on with cold plasma. Is that very similar to the wound healing, where you’re using the cold plasma to remove the bacteria?

So far, I’ve talked about the biotechnology aspects, or applications, of cold plasma. And I personally myself have worked on nearly a decade of working with cold plasmas for bacterial contamination or decontamination. And we had literature of different medias such as dry surfaces, moist surfaces, and liquids, and so on and if cold plasma can work on such surfaces, they should be able to work on food surfaces as well. So that’s when we started look at using cold plasmas on food materials. And we know food recall is a major issue to our society still today with Salmonella, E. coli, and so on. And when we looked at different produce and poultry, on a variety of bacteria, the results were varied with respect to bacteria or the smoothness of the food structure or surface—texture—but overall we were able to demonstrate the efficacy of cold plasmas on killing bacteria on food surfaces. And we also lately actually tested cold plasmas on seafood. And because we are located by the Gulf coast in Texas, and we actually tested on certain type of seafood.

The principle of operation is similar but different. The cold plasma produces the reactive species. They also have the tendency for reacting with bacterial cell surfaces as well as their functioning itself. So once you rupture the cell surfaces as well as their functioning mechanisms, you could actually kill colonies of bacteria in a very, very short period of time.

What would be some of the benefits of using cold plasma for the food sterilization?

That’s a good question. Traditionally right now I think the technologies being used are very common type of methods that you would actually use to clean any surfaces. Right now, depending on different types of poultry or produce, they use water, sometimes warm water or hot water. In rare cases, they would choose some chemicals to decontaminate and then wash it with water. And there has been some radiation technologies being explored such as gamma radiation and electron beam radiation. So there are issues with the current technologies, neither one is the very traditional heat-related or steam-related applications that are harder, both in terms of its operation as well as its efficacy, the guaranteed requirement for bacterial protection. And then the high energy applications, they are more capital intense and bulky and there are some risks involved with it.

The benefits for cold plasma compared to the existing technology would be as I said, it can be made much more user friendly and it can actually have significant bacterial protection provided its designed appropriately for the specific application—type of foods. And then the other benefits for the commercial aspect is it can be made much more cost effective for the amount of treatment, one they would choose when compared to the existing technologies.

Can you talk a little bit about where cold plasmas are in terms of regulations and being used in actual society? Are they right now just in labs, or we using them, are we going to be seeing them soon out in the general public?

Since I’ve been working on it, I personally would like to see this technology being used in public very soon and there has been very few commercial interest on this area because being that it’s a new field and it’s a growing field. There are a very small number of either large companies or small scale companies are looking into take a product from the lab setup into a commercially-viable setup, increasing the technology to a much higher level so it could be used by the end-user applications. It’s a growing field and I think this technology will be in the hands of the public in a very short period of time, hopefully in a few years but the interest is there to make it from the research level into a commercially-readily available plasma device that you could buy off the shelf.

I know besides the cold plasma, you’re also working with laser plasma. And I want to know the difference between the two and what your laser plasma project is.

Cold plasma, as I said, it’s a plasma near room temperature. Since it’s near room temperature, we use it for a variety of heat-sensitive applications. The laser-induced plasma that we work on, it’s mostly for studying the high-temperature, high-density plasmas that are near to the conditions that exist in the surface of the sun, but in a very microscopic scale. The interest towards laser plasmas, one for the understanding of plasma dynamics with its surrounding media, as being used in the fusion research applications, and also now we are looking at using laser plasmas to produce high temperature, microscopic plasmas in liquid medium in conjunction with materials such as gold or platinum to produce very high energy nanoparticles directly into the liquids. So those are some of the areas that we use laser plasmas, which are usually hot plasmas, for either studying fundamental plasma physics and celestial study, and the fundamental aspects of how nanoparticles can be produced directly in liquids that can be used for a variety of applications as well.

One of the major focuses of Sigma Xi is to strengthen the health of research enterprise and that involves supporting students. I know that supporting students and outreach is very important to you as well. Can you talk a little bit about what you’ve been doing for that?

Sure. Outreach is actually part of our culture in our program in our college at Texas A&M-Corpus Christi. We reach out to middle school, high school students when they come here for campus tours. We make sure that they visit our plasma lab and I personally myself provide the demo of some of the plasma equipment and I also have some of my students to talk to them. What is it like working in the lab? And we also do some competitions. Our college actually conducts annual Sigma Xi symposiums that involves students to present papers and conferences so when we ask our students to assist with these type of outreach activities, our students get really excited and become a team and we usually use our research team to give a demo for high school students, as well as our own undergraduate students. When they come here for campus visits, we have something called Islander Days, when we have students ready to apply for engineering programs, we give them a tour of the labs as well. And besides that, being in the minority serving in institutions we have reached to several students in the region where they enjoy more research experiences, or hands-on experiences, which usually they don’t get in other conditions. So these are some of the outreach activities that we do. And actually, I personally did a couple of years of engineering competitions where we made students build catapults and chariots based on basic raw materials that we supply. So outreach is part of our culture and we feel great about having those members joining the STEM education and the engineering program and some of them actually started working in our Plasma Engineering Research Lab.

And you have a little device to show us, maybe you use it during your outreach, of what the plasma looks like?

Yeah. So we call this a plasma ball and it produces something similar to cold plasma. I’m going to turn it on now [glass ball illuminates with plasma] and now you can see it, so there you go. So it puts out a plasma, or a range of plasmas to the outer surface, which is a glass that you see here. And then when you actually have a contact to it, you actually make much denser plasma and then all the other rays of plasma goes away, and it doesn’t burn your hand. If I hold it towards the camera, you can see it gets warmer but it doesn’t burn your finger. And the reason that it makes a contact to your finger, then when you release it, it makes it all over the chamber is basically because you supply these tactic electricity around your body or your ground, you act as a ground between one of the terminals and the other terminals. And this plasma, we also use it to demonstrate during the outreach how this ball can actually light up floors and bulbs without actually having it electronically connected. Basically, through electromagnetic radiation being used in this medium, as well as it radiates outside the glass, so when you bring in a flash lamp, it actually lights up based on electromagnetic radiation that comes out of this plasma bulb. So these are some of the tools that we use to get them started to see what plasma is about.

Thank you for showing that and thank you for explaining your research. It’s been great to talk to you

And it’s been a great pleasure, talking to you. And I feel glad being a member of Sigma Xi for several years, I’m very happy to share my experiences with the community. So thank you very much.

More Videos About Magesh's Research and Lab

PERL: A New Frontier
A video from Texas A&M University-Corpus Christi about the Plasma Engineering Research Lab.

News Report on the Plasma Engineering Research Lab