Plasma, ionised gas, is the fourth state of matter after solid, liquid and gas. The sun, the aurora and lightning are all natural examples, while plasma technologies include advanced silicon etching machines, space propulsion systems and nuclear fusion reactors. Atmospheric pressure plasma technologies can be used for chemical synthesis - scrambling molecules of nitrogen and oxygen in air, to produce nitrogen oxides and ozone. This mimics natural processes in lightning strikes and the atmosphere. These air-derived reactive gases - reactive oxygen and nitrogen species (RONS) - have antimicrobial, bioactive and chemical effects. Their potential industrial applications span chemicals, hygiene, agriculture, food, bioprocesses and healthcare. Fourth State's mission is to make the biochemical benefits of RONS accessible - anywhere, anytime - with just air and electricity, using its patented Air Plasma technology. One of the RONS generated by air-plasma, nitric oxide (chemical formula NO - not to be confused with nitrogen dioxide, NO2, or nitrous oxide, N2O) has been called a "miracle molecule" by scientists, due to its surprisingly important, diverse biological roles in animals, plants, fungi and microbes. NO is produced by almost every cell in the human body for a wide range of effects, including antimicrobial/anti-tumour action, control of blood flow and wound healing. Its discovery was awarded the 1998 Nobel prize in Physiology/Medicine. NO is used routinely as an inhaled drug, and was recently investigated as a COVID-19 rescue therapy. Numerous NO-based therapies are currently in development, but the limitations of conventional sources of NO - high pressure compressed gas cylinders and various chemicals - are a barrier to widespread use in healthcare and other applications. Fourth State currently sells its portable air plasma generators to translational researchers (NOxLab R&D products) and third party integrators/OEMs (ModuNOx OEM solutions). These products provide customers with an easy, (cost-)effective, safe and sustainable source of NO (and/or other RONS if desired). Users of NOxLab R&D products can quickly establish correct settings for their intended RONS application in a laboratory, before scaling up to pilot- and full-scale deployment through ModuNOx OEM solutions. This A4I project with the National Physical Laboratory (NPL) builds directly on previous collaborations, aimed at high-precision measurement of RONS generated by Fourth State's products. The first project between Fourth State and NPL was successfully delivered during the pandemic, through the Measurement for Recovery (M4R) programme - a case study on this project was recently published on NPL's website.

Fourth State makes products which generate useful reactive gases by combining ambient air and electricity; we specialise in generating oxides of nitrogen and ozone in-situ. Our technology is based on plasma (ionised gas), the fourth state of matter after solid, liquid and gas. This A4I feasibility project with The National Physical Laboratory will seek to improve concentration measurements for these substances produced by our products.

**COVID-19:** in December 2019, the Wuhan Municipal Health Committee identified an outbreak of viral pneumonia of unknown cause. Coronavirus RNA was quickly identified in some of these patients. This novel coronavirus has been designated SARS-CoV-2, and the disease caused by this virus defined as COVID-19\. This disease has now become pandemic, and with well over 1 million confirmed cases, 100,000 deaths and a case fatality rate that exceeds that of influenza by at least an order of magnitude. COVID-19 represents a substantial challenge to healthcare systems and economies worldwide. **Nitric Oxide (NO) gas:** (not to be confused with Nitrous Oxide, N2O, or Nitrogen Dioxide, NO2) is produced naturally by the body for controlling numerous bodily functions (e.g. blood flow, wound healing, inflammation) and as a potent antimicrobial (including against drug-resistant bacteria, fungi and viruses). NO inhalation therapy, in which NO gas in controlled concentrations is delivered to patients' lungs via ventilators, is an approved treatment for a number of respiratory conditions. Currently approved NO inhalation therapy systems mix NO gas, stored in large compressed gas cylinders, with air flow for breathing. NO inhalation is currently being investigated by several research groups worldwide for treatment and prevention of COVID-19 - the therapy previously showed promise during the 2002 SARS outbreak. **Problem:** assuming the therapy works in clinical studies, key barriers remain to rapid, widespread and cost-effective deployment. Current systems using compressed NO gas cylinders are prohibitively expensive (£100/hour over several days of continuous treatment) and only available for niche use - scaling up delivery to address COVID-19 would be expensive and logistically impractical. **Potential solution:** plasma technology (electrically ionised gas, the fourth state of matter after solid, liquid and gas) can produce NO in-situ from air (nitrogen and oxygen). Coupled in-line to existing ventilators, Fourth State's compact, modular and affordable plasma devices could intelligently deliver NO in the flow of air to the lungs, using just electricity as an input. Our devices have previously been independently verified by UK universities to produce NO in controlled quantities, with corresponding known biological effects (antimicrobial action, accelerated wound healing processes).

"Wounds to the skin normally heal quickly and efficiently, but this is not always the case. In fact, across Europe over 80 million people are currently suffering with a range of wounds that fail to heal. These chronic wounds can remain unhealed for many years, significantly decreasing quality of life and increasing the chance of developing major complications, including death. While there are many different causes of chronic wounds, recent studies have revealed the important role of bacteria and biofilms. Biofilms are complex and challenging, broadly defined as a group of microorganisms (usually bacteria) which come together to form a community, surrounded by a sticky matrix of sugars, proteins and DNA. Biofilms are surprisingly common in the environment, found in rivers, soil, inside pipes, on boat hulls and covering almost any moist surface. Our bodies are also home to biofilms, the dental plaque on your teeth, the bacteria living in your gut and more. While these are generally harmless, biofilms in chronic wounds can become a major clinical problem, impeding the body's natural ability to repair. Crucially, bacteria in wound biofilms can be up to 1000 times more resistant to current treatments. Fourth State medicine have developed an innovative new technology for the management of wound biofilms. Using a mixture of gases and electricity we will develop a new advanced wound dressing able to selectively target problematic biofilm bacteria. A key aspect of this proposal will be ensuring selectivity to manage these biofilm bacteria, while supporting the presence of beneficial bacteria. This is essential as at least 400 different types of bacteria, many of which are beneficial, cover our bodies. Our new technology will easily integrate into existing wound devices, ensuring rapid translation into wound care clinics across the world."

Fourth State Medicine has developed a novel plasma energy delivery system for the purposes of wrinkle removal in cosmetic surgery and wound care. With a large consortium covering the disciplines of medicine, engineering, distribution and research they aim to change the state of medicine through this innovative platform technology.