Cold atmospheric plasma activity on microorganisms. A study on the influence of the treatment time and surface (original) (raw)
The second half of the 20th century can be characterized and named as the 'plasma era', as the plasma gathered scientific interest because of its special physical behaviour. Thus, it was considered as the fourth material state and the plasma physics began to form consequently. In addition to this, many important applications of plasma were discovered and put to use. Especially, in last few decades, there has been an increased interest in the use of cold atmospheric plasma in biochemical applications. Until now, thermal plasma has been commonly used in many bio-medical and other applications; however, more recent efforts have shown that plasma can also be produced at lower temperature (close to the environment temperature) by using ambient air in an open space (in atmospheric pressure). However, two aspects remain neglected: firstly, low-temperature plasma production with a large area, and secondly, acquiring the necessary knowledge and understanding the relevant interaction mechanisms of plasma species with microorganisms. These aspects are currently being investigated at the 'Demokritos' Plasma Laboratory in Athens, Greece with radio frequency (27.12 MHz and it integer harmonics)-driven sub-atmospheric pressure plasma (100 Pa). The first aspect was achieved with atmospheric plasma being produced at a low temperature (close to the environment temperature) and in a large closed space systems. Regarding the plasma effect on living microorganisms, preliminary experiments and findings have already been carried out and many more have been planned for the near future.
Sign up to get access to over 50M papers
Sign up for access to the world's latest research
Related papers
Comparison of Direct and Indirect Effects of Non-Thermal Atmospheric-Pressure Plasma on Bacteria
Plasma Processes and Polymers, 2007
Effectiveness of non-thermal atmospheric pressure Floating Electrode Dielectric Barrier Discharge plasma in interaction with living organisms is investigated. Two regimes are analyzed: where this plasma comes in direct contact with the organism and where this plasma in separated for the treatment target by a grounded mesh. Direct plasma contact is found to be more efficient at sterilization and the mechanism is hypothesized to be due to charged species delivered by plasma to the surface of the organism.
Complex Responses of Microorganisms as a Community to a Flowing Atmospheric Plasma
Plasma Processes and Polymers, 2012
Low-temperature gas plasmas, and in particular cold atmospheric pressure plasmas (CAP), have been receiving increasing attention over recent years because of the potential applications they offer within the areas of medicine, food safety, and environmental remediation. [1-3] Active areas of research include blood coagulation, [4] wound and skin disinfection, [2,5,6] cancer therapy, [7-10] cosmetics, [11]
The interaction of a direct-current cold atmospheric-pressure air plasma with bacteria
Plasma Science, …, 2009
A direct-current cold atmospheric-pressure air plasma microjet (PMJ) based on the microhollow cathode discharge design is used to inactivate six types of bacteria within a small well-defined area on a large petri dish. We show that the PMJ is very effective in inactivating bacteria in their vegetative state as well as in the spore state within the area of plasma exposure. We also observed that bacteria in their vegetative state were inactivated efficiently outside the area of direct plasma exposure. Different bacteria responded differently to an increase in the plasma exposure (dose). Lastly, we observed two types of colony forming unit (CFU) distributions after plasma treatment; one distribution is diffusionlike with a gradual increase of the surviving CFU as one moves radially away from the area of direct plasma exposure, and the other distribution shows an essentially uniform reduction in surviving CFU across the entire petri dish.
Evaluation of the sensitivity of bacterial and yeast cells to cold atmospheric plasma jet treatments
Biointerphases, 2015
The focus of this research was first to determine the influence of the atmospheric plasma drive frequency on the generation of atomic oxygen species and its correlation with the reduction of bacterial load after treatment in vitro. The treatments were carried out using a helium-plasma jet source called PlasmaStream™. The susceptibility of multiple microbial cell lines was investigated in order to compare the response of gram-positive and gram-negative bacteria, as well as a yeast cell line to the atmospheric plasma treatment. It was observed for the source evaluated that at a frequency of 160 kHz, increased levels of oxygen-laden active species (i.e., OH, NO) were generated. At this frequency, the maximum level of bacterial inactivation in vitro was also achieved. Ex vivo studies (using freshly excised porcine skin as a human analog) were also carried out to verify the antibacterial effect of the plasma jet treatment at this optimal operational frequency and to investigate the effec...
Cold Atmospheric Plasma: Charged Species and Their Interactions With Cells and Tissues
IEEE Transactions on Plasma Science, 2008
Cold atmospheric plasma (CAP) treatment of living tissues becomes a popular topic in modern plasma physics and in medical sciences. The plasma is capable of bacterial inactivation and noninflammatory tissue modification, which makes it an attractive tool for wound healing and the treatment of skin diseases and dental caries. There are still many open issues with regard to the mechanisms of action of the plasma on bacteria and mammalian cells and tissues, both from the biological and the physical perspective. For example, the chemistry of CAP and the exact roles of various plasma constituents in tissue treatment are not yet fully resolved. In this paper, we shall concentrate on the charged species (electrons and ions) in the plasma. The selected physical properties of typical atmospheric plasma sources will be discussed; experiments will be confronted with theoretical considerations, and several biomedical aspects of CAP treatment will be surveyed. Index Terms-Cold atmospheric plasma (CAP), plasma medicine, surface treatment.
The bactericidal efficacy of cold atmospheric plasma technology on some bacterial strains
Egyptian Academic Journal of Biological Sciences, G. Microbiology, 2010
Plasma, a mix of ionized gas molecules and free electrons, is often referred to as the fourth state of matter. There are different applications of plasma in our life starts from easy lighting to disease fighting and it's nothing new. Fluorescent lights, air conditions and plasma televisions use it. One of its different types is atmospheric cold plasma, the possible applications for sterilization using cold plasmas range from the food industry to planetary space missions. The same technique could also be used on space craft leaving Earth to avoid transporting microorganisms from Earth to other planets or moons. The use of toxic chemicals to sterilize medical instruments may soon be a thing of the past because the use of cold plasma to sterilize heat-sensitive reusable medical tools in a rapid, safe, and effective way is bound to replace the present method which uses a toxic gas as ethylene oxide, in addition to its use for air purification. Lately it is tested to prepare surfaces for bonding and kill bacteria on delicate living tissues. We report the results of an interdisciplinary collaboration formed to assess the sterilizing capabilities of the cold atmospheric plasma. This newly-invented source of plasma is capable of operating at atmospheric pressure in air and other gases, and of providing antimicrobial activity at room temperature as judged by viable plate counts. Plasma exposures have reduced log numbers of three tested bacterial strains namely, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa seeded on solid surfaces of Muller-Hinton agar at room temperature. Initial experimental data showed ≥5 log 10 CFU reduction of bacteria when 5×10 6 cfu.ml-1 of samples seeded on MHA plates. Results showed >5 log 10 CFU reduction with E. coli when exposed for up to 360 sec to plasma while the same exposure time was required for 5 log 10 CFU reduction killing with S. aureus samples, the least affected by this treatment was Pseudomonas aeruginosa cell suspensions where there was a very few reduction in number of survivals (≤ 10% of the whole population) after the same exposure time application. For all microorganisms tested, a biphasic curve was generated when the number of survivors versus time was plotted in dose-response curves. In conclusion we can report that the atmospheric cold plasma generated by this method has proven sterilization (kill) capability against both gram-positive and gramnegative bacteria in different extents depending on special strain characteristics.
Low temperature atmospheric plasma for microbial decontamination
2013
Low temperature Plasma (LTP) is a high-energy gas that is created when an electrical current is passed through a gas. Until recently, plasmas could only be created at relatively high temperatures in a vacuum and the use of plasma on sensitive materials such as human tissue, food products, medical devices and the packaging industry, was therefore impractical. However, over the last few years technological breakthroughs have made it possible to produce low temperature plasmas under atmospheric conditions providing many advantages. Plasma discharges with a higher oxygen concentration have been associated with increased levels of microbial survival inhibition due to oxygen based active species, atomic oxygen and ozone. Low temperature plasmas have shown success in decontamination of a wide range of microorganisms including bacteria, fungi and algae and has even shown success in damaging bacterial spores. These factors have brought this exciting new, emerging technology to the forefront ...
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.