Mounir Laroussi

• PhD
• Professor at Old Dominion University

This work investigates the temporal dynamics of O atoms in nonequilibrium atmospheric pressure plasma (NAPP) generated by kHz nanosecond pulsed discharge. Two‐photon laser‐induced fluorescence (TALIF) method is used to measure the time resolution of O atom density from the first discharge pulse in two gas mixtures, He + 0.4%O 2 and He + 0.4%air. Th...

One can safely say that the pioneering work of Dr. Ulrich Kogelschatz and his team on the physics and chemistry of the dielectric barrier discharge was foundational and remain of great relevance to the present day. Kogelschatz and his team made some of the early high-resolution measurements of the current pulses associated with filaments and conduc...

Low temperature plasmas (LTPs) enable to create a highly reactive environment at near ambient temperatures due to the energetic electrons with typical kinetic energies in the range of 1 to 10 eV (1 eV = 11600K), which are being used in applications ranging from plasma etching of electronic chips and additive manufacturing to plasma-assisted combust...

Plasma medicine means the application of non-equilibrium plasmas at temperatures around body temperature, for therapeutic purposes. Non-equilibrium plasmas are weakly ionized gases, which contain charged and neutral species and electric fields and emit radiation particularly in the visible and ultraviolet range. Medically relevant cold atmospheric...

Plasma, the fourth and most pervasive state of matter in the visible universe, is a fascinating medium that is connected to the beginning of our universe itself. Man-made plasmas are at the core of many technological advances that include the fabrication of semiconductor devices, which enabled the modern computer and communication revolutions. The...

p>Plasma, the fourth and most pervasive state of matter in the visible universe, is a fascinating medium that is connected to the beginning of our universe itself. Man-made plasmas are at the core of many technological advances that include the fabrication of semiconductor devices, which enabled the modern computer and communication revolutions. Th...

Plasma, the fourth and most pervasive state of matter in the visible universe, is a fascinating medium that is connected to the beginning of our universe itself. Man-made plasmas are at the core of many technological advances that include the fabrication of semiconductor devices, which enabled the modern computer and communication revolutions. The...

Studies on the interaction of plasma generated at atmospheric pressure and at room temperature (low temperature plasma or just cold plasma) with biological cells and tissues have revealed that cold plasma has therapeutic effects that form the basis for new medical therapies. Cold plasma exhibits bactericidal properties and at low doses can modulate...

This mini review is to introduce the readers of Plasma to the field of plasma medicine. This is a multidisciplinary field of research at the intersection of physics, engineering, biology and medicine. Plasma medicine is only about two decades old, but the research community active in this emerging field has grown tremendously in the last few years....

Simple Summary Cold physical plasma is a partially ionized gas generating various reactive oxygen and nitrogen species (ROS/RNS) simultaneously. ROS/RNS have therapeutic effects when applied to cells and tissues either directly from the plasma or via exposure to solutions that have been treated beforehand using plasma processes. This review address...

This paper reviews the principles behind the design and operation of the resistive barrier discharge, a low temperature plasma source that operates at atmospheric pressure. One of the advantages of this plasma source is that it can be operated using either DC or AC high voltages. Plasma generated by the resistive barrier discharge has been used to...

The dielectric barrier discharge (DBD) is one of the most used low temperature plasma sources. Its industrial and biomedical applications are numerous. In this paper first the history of the development of the DBD is recounted and then its use in biomedical applications is discussed with a focus on biological decontamination. Recent events and chal...

Cancer treatment is a promising clinical application of cold atmospheric plasma due to its selectivity in killing cancer cells. Whether there are differences in selectively killing of canners among direct plasma treatment, plasma activated media (PAM) and exogenous RONS solutions made by chemical methods is an important issue that needs to be addre...

In this Chapter, the physics and engineering of low-temperature plasma sources used in plasma medicine are covered. First, an overall review of the major plasma devices is presented. This is followed by a detailed description of one of the major plasma sources used in plasma oncology, the Nonequilibrium Atmospheric Pressure Plasma Jet (N-APPJ).

Cold plasma-activated solution (PAS), particularly the cold plasma-activated medium (PAM), is a type of chemotherapy used in the cold plasma-based cancer treatment. Compared with the direct cold plasma treatment, PAM can be stored for a long time and can then be used without dependence on cold plasma sources or devices. Many in vitro and in vivo ex...

For many decades non-equilibrium plasmas (NEPs) that can be generated at atmospheric pressure have played important roles in various material and surface processing applications [...]

Low temperature plasmas that can be generated at atmospheric pressure and at temperatures below 40°C have in the past couple of decades opened up a new frontier in plasma applications: biomedical applications. These plasma sources produce agents, such as reactive species (radicals and non-radicals), charged particles, photons, and electric fields,...

In this paper the generation and diagnostics of a reduced pressure (300 mTorr to 3 Torr) plasma generated inside an electrodeless containment vessel/chamber are presented. The plasma is ignited by a guided ionization wave emitted by a low temperature pulsed plasma jet. The diagnostics techniques include Intensified Charge Coupled Device (ICCD) imag...

A chiral plasma plume has recently been reported inside a circular quartz tube without the use of an external magnetic field. It is believed that the quartz tube plays an important role in the formation of the chiral plasma plume. In this paper, to better understand how this interesting structure is generated, the effect of the tube geometry on the...

Scientific breakthroughs tend to come in spurts when unique societal, economical, and political circumstances conspire (knowingly or unknowingly) and create an environment ripe for creativity. The field of low temperature plasma (LTP) recently experienced such an upheaval, which this paper attempts to relate in some details. There have been “roadma...

Low temperature plasma jets are unique plasma sources capable of delivering plasma outside of the confinement of electrodes and away from gas enclosures/chambers [...]

The effects of plasma activated media, PAM, on cells are mediated by the short and long lived species that are generated at the plasma-liquid interface and that diffuse into the liquid bulk and induce secondary reactions which in turn produce new long lived species such as hydrogen peroxide and peroxynitrite. In this paper, in order to investigate...

Non-equilibrium atmospheric pressure plasma jets (N-APPJs) generate plasma in open space rather than in a confined chamber and can be utilized for applications in medicine. This book provides a complete coverage to this fast-emerging field, from the fundamental physics, to diagnostics techniques of the plasma and reactive species measurements. It p...

The International Workshop on Plasma for Cancer Treatment, IWPCT, is an international workshop that focuses on basic and clinical research into the interaction of low temperature plasmas (LTP) with cancer cells and tumors. It was founded in 2014 by Prof. M. Keidar and Prof. M. Laroussi as a venue for researchers to present their cutting edge resear...

This mini review is to introduce the readers of Plasma to the field of plasma medicine. This is a multidisciplinary field of research at the intersection of physics, engineering, biology and medicine. Plasma medicine is only about two decades old, but the research community active in this emerging field has grown tremendously in the last few years....

Low-temperature plasma (LTP) has been shown to have killing effects on cancer cells both in vitro and in vivo [1] – [5]. One of the approaches in treating mammalian cells with LTP is through plasma activated media (PAM). PAM is produced by exposing cell culture media to plasma. While the adverse effects of PAM treatment on cancerous cell lines have...

When operated in an environment containing oxygen and nitrogen low temperature atmospheric pressure plasmas generate copious amounts of reactive oxygen species (ROS) and reactive nitrogen species (RNS). These species can be transported to react with biological matter and induce cellular effects ranging from inactivation to proliferation, depending...

Low temperature plasmas have been used in various plasma processing applications for several decades. But it is only in the last thirty years or so that sources generating such plasmas at atmospheric pressure in reliable and stable ways have become more prevalent. First, in the late 1980s, the dielectric barrier discharge was used to generate relat...

Low-temperature plasma has been shown to have diverse biomedical uses, including its applications in cancer and wound healing. One recent approach in treating mammalian cells with plasma is through the use of plasma activated media (PAM), which is produced by exposing cell culture media to plasma. While the adverse effects of PAM treatment on cance...

Low-temperature, atmospheric pressure plasmas (LTPs) produce reactive oxygen and nitrogen species [O, O − 2 , O 2 (1), hydroxyl (OH), H 2 O 2 , NO, NO 2. . .]. In biological and medical applications, the concentrations and fluxes of these species play a crucial role in the biological outcomes. Many of these species are produced in the gaseous phase...

Klaus-Dieter Weltmann and Mounir Laroussi, the authors of this dedication, would like to thank the Editor-in-Chief, Steven Gitomer, and the Editorial Board of the IEEE Transactions on Plasma Science for agreeing to dedicate this special issue on Atmospheric Pressure Plasmas and their Applications to the memory of Dr. Ulrich Kogelschatz, one of the...

The efficacy of low temperature plasma generated by an atmospheric pressure plasma jet, J-Plasma system (™Bovie Medical Corporation), is studied for its therapeutic effects against the DU145 prostate cancer cell line. The DU145 cells in complete culture media were treated with different exposure times and different J-Plasma system parameters. The o...

Plasma-activated media (PAM) can be as effective as direct plasma treatment in killing cancer cells. PAM is produced by exposing liquid cell culture media to low temperature plasma. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the aqueous state play key role in the anti-tumor effects of PAM. The effectiveness of PAM is highl...

Non-equilibrium atmospheric-pressure plasmas have recently become a topical area of research owing to their diverse applications in health care and medicine, environmental remediation and pollution control, materials processing, electrochemistry, nanotechnology and other fields. This review focuses on the reactive electrons and ionic, atomic, molec...

The interaction of low temperature plasma with liquids is a relevant topic of study to the field of plasma medicine. This is because cells and tissues are normally surrounded or covered by biological fluids. Therefore, the chemistry induced by the plasma in the aqueous state becomes crucial and usually dictates the biological outcomes. This process...

Low temperature plasma jets are the product of fast ionization waves that are guided within a gas channel. Here, we present a novel way to use an ionization wave from an external plasma jet to remotely produce a large-volume diffuse low pressure plasma inside an electrodeless Pyrex chamber.

The application of low temperature plasmas in biology and medicine may lead to a paradigm shift in the way various diseases can be treated without serious side effects. Low temperature plasmas generated in gas mixtures that contain oxygen or air produce several chemically reactive species that have important biological implications when they intera...

The study of the effects of low temperature plasma (LTP) on cancer cells, in vitro and in vivo, is today one of the most active research areas of plasma medicine. Here, we study the interaction of LTP with cancer cells which were grown overnight and then seeded into MEM (minimal essential medium) growth culture treated by the plasma pencil at diffe...

This paper summarizes the Dr. Robert J. Barker memorial session at the IEEE International Conference on Plasma Science 2014. Each section summarizes progress in a plasma research area strongly influenced by Dr. Barker's leadership: 1) plasma medicine; 2) atmospheric-pressure plasmas; 3) high-power microwaves; 4) pulsed power; and 5) numerical simul...

Low-temperature plasma jets launched in room air are unique plasma sources in the sense that they provide a volume of plasma outside the confines of electrodes and gas enclosures. This is an extremely attractive property for medical applications where the target is usually a biological tissue located in normal and unobstructed room conditions. It w...

This is an essay that briefly reviews and discusses the application of low temperature plasma (LTP) to kill cancer cells. Some historical background is given and the views and opinions of the author about the present and future of the field are presented.

Low-temperature atmospheric pressure plasmas (LTAPPs) have garnered great scientific interest in recent years because of their chemically reactive properties. The LTAPP is currently being studied for potential applications in the field of plasma medicine including, but not limited to, wound healing and cancer therapy. In this paper, images of fibro...

One of the most spectacular shows that nature offers at northern latitudes is what is known as northern lights or Aurora Borealis. The Aurora Borealis is caused by energetic particles of the solar wind, which get trapped in Earth's magnetosphere. To simulate this phenomenon on a table top scale, we ignited a plasma jet and introduced the fast trave...

The efficacy of the plasma pencil is studied for its cancer therapeutics effects against the SCaBER cell line. First, the SCaBER cells in media were treated with different exposure times of low temperature plasma (LTP). Secondly, LTP activated media was generated by treating the media prior to adding it to the cells. Cell viability was assayed at 0...

This review focuses on one of the fundamental phenomena that occur upon application of sufficiently strong electric fields to gases, namely the formation and propagation of ionization waves–streamers. The dynamics of streamers is controlled by strongly nonlinear coupling, in localized streamer tip regions, between enhanced (due to charge separation...

Low temperature plasma (LTP) generates biologically tolerable gas discharges, suitable for the treatment of biological tissues 1 . In recent years extensive research has been done on the biomedical applications of LTP including bacteria inactivation and cancer cell treatment.

Low temperature plasma jets are being extensively used in plasma processing including biomedical applications. This is due to their ability of launching controllable plasma plumes in atmospheric pressure air, not confined by electrodes. These plasma jets are in fact vehicles transporting reactive chemical species to a remote substrate in the form o...

Low temperature plasmas in air or air-containing mixtures produce reactive oxygen species (ROS) such as O, O 2 − , and OH and reactive nitrogen species (RNS) such as NO and NO 2 which exhibit strong oxidative properties and/or trigger signaling pathways in biological cells 1 . In such chemically reactive environment bacterial cells were found to di...

Squamous cell carcinoma of the bladder is a rare type of bladder cancer that forms as a result of chronic irritation of the epithelial lining of the bladder. The cell line used in this paper is SCaBER (ATCC HTB3) derived from squamous cell carcinoma of the human urinary bladder. Current treatments of bladder cancer include surgery, radiation, and c...

Biologically tolerant plasmas (BTPs) are plasmas with gas temperatures less than 40 °C that are generated near atmospheric pressures and in non-toxic gases such as air or helium. BTPs have recently garnered great interest as a therapeutic for cancer. Here, we review and discuss conventional cancer treatments, some of the plasma devices that are cur...

To understand the self sustained propagation of the plasma jet/bullet in air under atmospheric pressure, the ignition of the plasma jet/bullet, the plasma jet/bullet ignition point in the plasma pencil, the formation time and the formation criteria from a dielectric barrier configured plasma pencil were investigated in this study. The results were...

Objectives: To evaluate the safety and effectiveness of the plasma pencil (PP) device in conjunction with H2 O2 gel. The purpose of this study was to determine whether LTAPP delivered using the PP would enhance the tooth-whitening process while causing no thermal threat. Methods: The study consisted of thirty extracted human teeth that were rand...

In this paper He-discharge (plasma jet/bullet) in atmospheric pressure air and its progression phenomenon has been studied experimentally using ICCD camera, optical emission spectroscopy (OES) and calibrated dielectric probe measurements. The repetitive nanosecond pulse has applied to a plasma pencil to generate discharge in the helium gas channel....

A plasma generator having a dielectric body; a first end wall and a second end wall attached or coupled to each end of the dielectric body to define a cavity within the dielectric body, and wherein the second end wall includes at least one discharge aperture formed therein; at least one gas inlet formed proximate the first end of the dielectric bod...

In this paper, we investigate the effects of various background gases on the formation and sustenance of a plasma jet. A helium plasma is ignited inside a dielectric tube and introduced into a vacuum chamber where the gas composition and pressure can be controlled. The gas composition inside the chamber is altered by separately injecting various ba...

The effect of low-temperature atmospheric pressure plasma towards the progression of cancerous human T-cell leukemia cells was investigated. The plasma pencil, which utilizes short duration high voltage pulses, was used to generate a low-temperature plasma (LTP) plume in ambient air. Our data showed that cell morphology and cell viability were affe...

Research on the biomedical applications of low temperature plasmas started with small scale experiments that were simply aimed at discovering what happens to biological cells when exposed to the chemically rich environment of plasma. These early experiments took place in the mid to late 1990s. As interest in this multidisciplinary field dramaticall...

The dynamics of non thermal plasma jets consisting of plasma bullets change with background gas pressure. Our recent study indicates that this dependence is not limited to the pressure alone but also to a physical boundary confining the working gas flow. It is observed that in a Helium filled chamber, no plasma bullet propagation occurs; however in...

form only given. Non thermal atmospheric gas plasmas have been exploited in biology, medicine, dentistry, and material science as a novel technology for health care. The unique enhanced helium gas-phase chemistry of the plasma plume is obtained when the electrons undergo collisions with the background gas and facilitate the formation of radical and...

Acute lymphoblastic leukemia (ALL) is one of the most common cancers diagnosed in children1. Breakthroughs such as tyrosine kinase inhibitors and other targeted treatments have increased overall patient survivability. However, chemotherapeutic agents can lead to acquired molecular resistance resulting in recurrent tumor tissue, severe toxicity in n...

form only given. Atmospheric pressure low temperature plasma jets were found to consist of ionization waves called “Plasma Bullets” that travel in ambient air at supersonic speeds. [1] Plasma jet's behavioral changes are known to depend on the background gas pressure the bullets propagate in. [2] Our recent study shows that this dependence is not o...

More than 50 million surgical and invasive medical procedures—includ-ing approximately 5 million gastroin-testinal endoscopies—are performed each year in the US alone. During these procedures, the close contact between surgical instruments and the exposed tissues of the patient can constitute an additional health risk due to the increased possibili...

In this study, we report insights into the dynamics of atmospheric-pressure low-temperature plasma jets (APLTPJs). The plasma jet current was measured by a Pearson current monitor for different operating conditions. These jet current measurements confirmed a proposed photo-ionization model based on streamer theory. Our results are supported by inte...

Because of their capabilities to generate plasmas that are not confined between electrodes, low-temperature plasma jets offer unique opportunities for applications such as material processing and biomedicine. The need to generate multiple jets in order to cover larger treatment areas has recently become desirable. However, the interaction between n...

Foreword R. Satava and R. J. Barker; Part I. Introduction to Non-equilibrium Plasma, Cell Biology, and Contamination: 1. Introduction M. Laroussi; 2. Fundamentals of non-equilibrium plasmas M. Kushner and M. Kong; 3. Non-equilibrium plasma sources M. Laroussi and M. Kong; 4. Basic cell biology L. Greene and G. Shama; 5. Contamination G. Shama and B...

Atmospheric-pressure non-equilibrium plasma jets (APNP-Js), which generate plasma in open space rather than in a confined discharge gap, have recently been a topic of great interest. In this paper, the development of APNP-Js will be reviewed. Firstly, the APNP-Js are grouped based on the type of gas used to ignite them and their characteristics are...

Cold plasma jets produced by pulsed discharges have recently attracted attention because of their physical properties enabling the development of new applications, such as plasma medicine. ICCD pictures of these jets revealed that they were composed of plasma bullets propagating at high velocity. When two plasma bullets interact in two counter-prop...

Cold plasma jets produced by pulsed discharges have recently attracted a lot of attention because of their unusual physical properties enabling the development of new applications, particularly for plasma medicine. ICCD pictures of these jets revealed that they were not continuous plasmas but composed of plasma bullets propagating at very high velo...

It is now well known that low-temperature plasmas can inactivate bacteria effectively. At low doses, these plasmas can also help in the proliferation of healthy fibroblasts and detach damaged cells without causing necrosis. The combination of these characteristics leads to the possibility of using plasmas in biomedical applications such as wound he...

Plasma bullets have recently been used in novel appli- cations in biology and medicine, which spurred interesting devel- opments in the new interdisciplinary field of "Plasma Medicine." In this paper, using high speed ICCD camera images we show that during their lifetime, plasma bullets undergo three distinc- tive phases: a launching phase during w...

In this paper we investigate the effects of ambient pressure on a plasma jet. This is done by first generating a plasma jet using our tube reactor device which emits a plasma plume in ambient air when high voltage pulses are applied to its two electrodes and a gas such as helium is flown through it. In the experiments reported here the jet is intro...

Here we report on a method to generate a long plasma plume and to ignite a large volume plasma by means of the jet. The plasma plume is generated by our tube reactor and then introduced into a chamber where the pressure is controlled. We discovered there are three operating phases: A phase where the plume length remains approximately constant, foll...

form only given. The plumes generated by low temperature plasma jets were found to consist of plasma packets/bullets traveling at high velocity. For the case of pulsed devices and when helium is used as the operating gas, two main factors influence the plasma bullet lifetime and therefore the length of the plume. These factors are the helium mole f...

species that undergo interaction with the biological systems under treatment. The behaviors of emitting species are studied for different HV pulse amplitudes, pulse widths, repetition rates, and gas flow rates. These species include N2 SPS (0-0) band at 337 nm, N/ FNS (0-0) band at 391 nm, OH (A-X) at 308 nm, He (23 P_33S) at 706 nm, and 0 (35S_35p...

The biomedical application of low-temperature atmospheric pressure plasma (LTAPP) is a collaborative interest for engineering, medical, dental, and biological researchers. This laboratory study tested whether LTAPP can limit the growth of Porphyromonas gingivalis, a periodontal pathogen strongly associated with periodontal disease, disease progress...

Non-thermal plasma jets in open air are composed of ionization waves commonly known as 'plasma bullets' propagating at high velocities. We present in this paper an experimental study of plasma bullets produced in a dielectric barrier discharge linear-field reactor fed with helium and driven by microsecond high-voltage pulses. Two discharges were pr...

Amyloid fibrils are ordered beta-sheet aggregates that are associated with a number of neurodegenerative diseases such as Alzheimer and Parkinson. At present, there is no cure for these progressive and debilitating diseases. Here we report initial studies that indicate that low temperature atmospheric pressure plasma can break amyloid fibrils into...

Plasma bullets generated by atmospheric pressure low temperature plasma jets have recently been an active research topic due to their unique properties and their enhanced plasma chemistry. In this paper, experimental insights into the plasma bullet lifetime and its velocity are reported. Data obtained from intensified charge-coupled device camera a...