Plasma Activated Media
Plasma activated media are media (mostly liquids) that contain a certain concentration of reactive species, mainly reactive oxygen and nitrogen species (RONS), which were generated by the interaction of a plasma with the liquid. When a liquid solution is in contact with a plasma at atmospheric pressure for a certain period of time, the reactive species generated in the plasma penetrate the medium and remain stable in it for periods ranging from a few hours to several weeks or even months. This allows them to be used in medicine, biology, food technology, etc. Furthermore, plasma activated media can act in places where direct plasma treatment is not possible such as cavities or other places that are difficult to reach.
Plasma-activated media, in general PAM, and plasma-activated water (PAW) in particular have attracted the attention of researchers in medicine, agriculture, and food science and technology due to their ability to induce oxidative stress to cells. This oxidative stress is well tolerated by healthy cells but destroys bacteria, including those resistant to antibiotics, and even viruses.
A recent study published by Kinga Kutasi and his collaborators presents an extensive comparison between different systems for liquid media activation. Specifically, systems for the activation of deionized water (DIW), phosphate buffered saline (PBS), phosphate buffer (PB), N-Acetyl-cysteine and saline were studied. The comparison was carried out by studying the concentration of different reactive species in the liquid medium, specifically H2O2, NO2 y NO3.
ION BIOTEC has developed a new technology capable of achieving concentrations of more than 100 mg/l of these species in deionized water that remain stable for weeks. Furthermore, while most devices activate liquid volumes of a few milliliters and require very long treatment times, at ION BIOTEC we have a high-tech system that reduces treatment times and increases production volumes.
The figure shows two spectra in the visible and ultraviolet range obtained during the production of plasma activated water in ION BIOTEC. The spectral lines showing the relative abundance of oxigen and nitrigen ion species (NO, OH, N+,O+ and excited N2) are cleary visible. These species are absorbed by the water forming nitrates, nitrites and hidrogen peroxide among other compunds.
Several scientific studies have shown the excellent results of the use of plasma activated media in medicine in relation to sterilization of living tissues, non-necrotic coagulation, destruction of tumor cells, wound healing, disinfection of medical equipment, and even, the use of plasma activated water as a mouthwash to treat dental problems.
Plasma-activated buffer solutions and cell culture media have also been studied for therapeutic purposes and they have shown a great potential to be used in cancer treatment.
In recent years, the medical research on plasma activated media has focused much of its efforts on fighting cancer.
Numerous scientific studies have demonstrated the antitumor effect of plasma activated media on different types of cancer cells and several publications show how this treatment is selective towards cancer cells while healthy cells are not affected.
In the field of agriculture, irrigation with plasma activated water has been shown to improve seed germination and plant growth. Water quality, mineralization, and chemical composition. Particularly, pH and nitrogen compounds, play a crucial role in the development and growth of plants. Plasma treatment of water results in a significant change in its properties such as pH, oxidation and reduction potential (ORP), conductivity, and concentration of reactive oxygen and nitrogen species (RONS).
Plants are highly vulnerable to pathogen attacks and environmental stress, as they are exposed to hostile environments under natural conditions. However, they have developed a self-defense system by which reactive oxygen and nitrogen species (RONS) act as regulators of this environmental stress. Cold plasma activated water (PAW) helps activate the components of the plant’s immune system, thus protecting it from the attack of various pathogens.
The treatment of food with plasma activated water is an alternative to the use of antibiotics and chemicals in food safety without affecting its organoleptic properties.
In recent years, numerous scientific studies have been carried out to prove the effectiveness of plasma-activated media in disinfecting food without affecting its taste or properties. Studies have revealed that plasma-activated water has the ability to inactivate microbial cells and it has been used successfully in the inactivation of different types of food pathogens such as mushrooms, strawberries, spinach, meet and eggs. Plasma activated water has even been used to increase the durability of squid.