Low temperature plasma-based sterilization overview and state-of-the-art (original) (raw)

Biomedical applications and diagnostics of atmospheric pressure plasma

Journal of Physics: Conference Series, 2012

Numerous applications of non-equilibrium (cold, low temperature) plasmas require those plasmas to operate at atmospheric pressure. Achieving non-equilibrium at atmospheric pressure is difficult since the ionization growth is very fast at such a high pressure. High degree of ionization on the other hand enables transfer of energy between electrons and ions and further heating of the background neutral gas through collisions between ions and neutrals. Thus, all schemes to produce non-equilibrium plasmas revolve around some form of control of ionization growth. Diagnostics of atmospheric pressure plasmas is difficult and some of the techniques cannot be employed at all. The difficulties stem mostly from the small size. Optical emission spectroscopy and laser absorption spectroscopy require very high resolution in order to resolve the anatomy of the discharges. Mass analysis is not normally applicable for atmospheric pressure plasmas, but recently systems with triple differential pumping have been developed that allow analysis of plasma chemistry at atmospheric pressures which is essential for numerous applications. Application of such systems is, however, not free from problems. Applications in biomedicine require minimum heating of the ambient air. The gas temperature should not exceed 40 o C to avoid thermal damage to the living tissues. Thus, plasmas should operate at very low powers and power control is essential. We developed unique derivative probes that allow control of power well below 1 W and studied four different sources, including dielectric barrier discharges, plasma needle, atmospheric pressure jet and micro atmospheric pressure jet. The jet operates in plasma bullet regime if proper conditions are met. Finally, we cover results on treatment of bacteria and human cells as well as treatment of plants by plasmas. Localized delivery of active species by plasmas may lead to a number of medical procedures that may also involve removal of bacteria, fungi and spores.

Low-Temperature Plasmas for Medicine?

IEEE Transactions on Plasma Science, 2009

Can low-temperature plasma technology play a role in medicine? This is a question that many investigators today are trying hard to give a positive answer to. It did not quite start out this way. Almost two decades ago, few "curious" electrical engineers and physicists with the help of few "brave" biologists/ microbiologists asked themselves more basic questions: What happens to biological cells if they were exposed to low-temperature plasma? Will they die? Will they survive? If they survive, will they come out the same or somehow "injured"? If injured, will they be able to repair the damage and recover? What kind of damage? Which plasma agent causes the damage? etc. As will be shown in this paper, some of these fundamental questions have been partially or fully answered, but until today, a complete picture has yet to emerge. This is good and not so good. It is good because if we already knew all the answers, we would not be looking forward to a more exciting research. It is not so good because after all these years, we are still quite a ways from an implementable medical application. In this review paper, the present state of knowledge regarding the effects of cold plasma on bacteria cells (prokaryotes) and on eukaryotic cells (such as mammalian cells) will be presented. As medical applications where low-temperature plasma is showing signs of success, blood coagulation and wound healing will be described.

Atmospheric-pressure plasma sources: Prospective tools for plasma medicine

Pure and Applied Chemistry, 2010

Plasma-based treatment of chronic wounds or skin diseases as well as tissue engineering or tumor treatment is an extremely promising field. First practical studies are promising, and plasma medicine as an independent medical field is emerging worldwide. While during the last years the basics of sterilizing effects of plasmas were well studied, concepts of tailor-made plasma sources which meet the technical requirements of medical instrumentation are still less developed. Indeed, studies on the verification of selective antiseptic effects of plasmas are required, but the development of advanced plasma sources for biomedical applications and a profound knowledge of their physics, chemistry, and parameters must be contributed by physical research. Considering atmospheric-pressure plasma sources, the determination of discharge development and plasma parameters is a great challenge, due to the high complexity and limited diagnostic approaches. This contribution gives an overview on plasm...

Cold Atmospheric Pressure Plasma Technology for Biomedical Application

Plasma Science and Technology [Working Title], 2021

Cold plasma generated in an open environment with a temperature nearly around room temperature has recently been a topic of great importance. It has unlocked the door of plasma application in a new direction: biomedical applications. Cold atmospheric pressure (CAP) plasma comprises various neutral and charged reactive species, UV radiations, electric current/fields etc., which have several impactful effects on biological matter. Some of the significant biological effects of CAP plasma are inactivation of microorganism, stimulation of cell proliferation and tissue regeneration, destruction of cells by initializing apoptosis etc. Although the detailed mechanism of action of plasma on biomaterials is still not completely understood, some basic principles are known. Studies have indicated that the reactive oxygen species and nitrogen species (ROS, RNS) play a crucial role in the observed biological effects. In this perspective, this chapter first provides a brief discussion on the funda...

A novel plasma source for sterilization of living tissues

New Journal of Physics, 2009

A source for the production of low-power plasmas at atmospheric pressure, to be used for the nondamaging sterilization of living tissues, is presented. The source, powered by radiofrequency and working with a helium flow, has a specific configuration, studied to prevent the formation of electric arcs dangerous to living matter. It is capable of killing different types of bacteria with a decimal reduction time of 1-2 min; on the contrary, human cells such as conjunctival fibroblasts were found to be almost unharmed by the plasma. A high concentration of OH radicals, likely to be the origin of the sterilizing effect, is detected through their UV emission lines. The effect of the UV and the OH radicals on the fibroblasts was analysed and no significant effects were detected.

Plasma Therapy: An Overview

Journal of Indian Academy of Oral Medicine and Radiology, 2011

Definition: Plasma, the fourth state of matter, is a collection of charged particles (electrons, ions, neutral atoms). Recent demonstration of plasma technology in treatment of living cells, tissue and organs are creating a new field at the intersection of plasma science and technology with biology and medicine known as plasma medicine. Plasma medicine is one of the newest fields of modern applied plasma chemistry. It appeared several years ago and comprises studies concerning the direct action of low-temperature, one atmosphere air plasma (cold plasma/nonthermal plasma/nonequilibrium) on body tissues for various noninvasive therapeutic treatments or diagnostics purpose. The study of plasma holds promise for a myriad of applications ranging from lasers and electronics, hazardous decontamination, sterilization and disinfection of foods, soil, water, instruments, to medical uses in wound healing and treating certain types of tumors and cancers. Plasma represents a new state-of-the-art sterilization and disinfection treatment for certain oral and environmental pathogens, heat-sensitive materials, hard and soft surfaces, and may assist health care facilities in the management of various health concerns. The role that low temperature atmospheric pressure plasma (LTAPP) could play in the inactivation of pathogenic microorganisms might prove to be a new, faster, more economical alternative.

Special Issue “Plasma Technology for Biomedical Applications”

Applied Sciences

The use of plasmas for biomedical applications in encountering a growing interest, especially in the framework of so-called “plasma medicine”, which aims at exploiting the action of low-power, atmospheric pressure plasmas for therapeutic purposes [...]

Non-Thermal Atmospheric-Pressure Plasma Possible Application in Wound Healing

Biomolecules and Therapeutics, 2014

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