Cold atmospheric plasma for viral decontamination

The COVID-19 pandemic has revealed a clear need for the efficient decontamination of surfaces and objects of daily use to reduce the transmission of the virus through smear infection. Objects that cannot be decontaminated using liquid disinfectants or heat can present a particular challenge. The availability of alternative approaches is crucial here to containing the epidemic spread of viral or other microbial pathogens. In his international FWF urgent funding project, Thomas Lion (St. Anna Childrens Cancer Research, Vienna; in the picture) together with Vladimir Scholtz (UCT, Prague, Czech Republic) focus on the reuse of highly effective face masks and the decontamination of other sensitive objects with new, safe, and environmentally friendly decontamination technology. Safe and environmentally friendly method of decontamination Cold atmospheric plasma (CAP) is a newly developed method for the decontamination of objects from micro-organisms. Besides its outstanding effectiveness, CAP technology is also affordable, gentle on materials, and safe for people and the environment. Its effectiveness in bacterial disinfection is already well-established. More recent studies have also shown CAPs suitability for efficient virus inactivation, but more data is needed on the optimal conditions for inactivation and related mechanisms. In an international research project funded by the FWF as well as the GACR (Czech Science Foundation), Thomas Lion of St. Anna Childrens Cancer Research in Vienna and Vladimir Scholtz of UCT in Prague, Czech Republic, are adapting CAP technology so that heat or liquid-sensitive objects can be reused after decontamination. The focus of their research is on the reuse of highly effective face masks as well as the decontamination of other sensitive objects. The aim is to investigate the effectiveness of CAP using selected human respiratory viruses with different properties, such as SARS-CoV-2, influenza A, adenovirus, and rhinovirus. The results of this study will contribute to establishing CAP technology as a safe and affordable alternative to current means of virus decontamination, especially in times of increased demand and scarcity of disinfectants. An understanding of the mechanisms underlying CAP-induced virus inactivation will enable Lion and Scholtz to identify the strengths of the approach and to address any potential weaknesses as the basis for its widespread use.

In a world where infectious diseases pose significant threats to public health, researchers have been investigating innovative technologies for effective decontamination. One such promising technology is Non-Thermal Plasma (NTP), which has demonstrated remarkable efficiency against various microorganisms without damaging sensitive materials. We developed a low-cost, handheld cold air plasma device that consists of two electrodes and an inexpensive power supply, generating a corona discharge that effectively inactivates a wide spectrum of pathogens. Testing revealed impressive results against various microorganisms, including gram-positive bacteria, gram-negative bacteria, yeasts, and microfungi. The bactericidal effect appears to be primarily attributable to reactive oxygen species, particularly ozone. During the COVID-19 pandemic, the shortage of personal protective equipment highlighted the need for decontamination methods that would permit safe reuse of protective gear. Our research shows that NTP treatment completely inactivates SARS-CoV-2 and other common respiratory viruses, including Influenza A, Rhinovirus, and Adenovirus. Unlike harsh methods such as autoclaving, NTP preserves both the filtering efficiency and microstructure of high-efficiency P3 R filters, making it an ideal solution for decontamination of personal protective equipment. Comprehensive testing of NTP on everyday materials demonstrated its gentle nature. Paper remained fully functional despite minor changes like whitening and pH shifts. Metals such as copper, tinned copper, brass, and stainless steel experienced mild oxidation that did not affect their functionality. Electronic components showed negligible changes, with only slight measurement shifts observed in humidity sensors. These findings confirm that NTP is suitable for decontaminating various sensitive materials without compromising their performance. We exploited the indicated properties including inactivation of respiratory viruses and gentleness on sensitive materials to test NTP application on sensitive materials which may be relevant in the pediatric oncology setting, such as plush toys, paper, and rubber. Again, we were able to fully decontaminate these materials without compromising their functionality. The research also explored innovative applications by combining NTP technology with antimicrobial materials. 3D-printed substrates coated with silver nanoparticles and protected by a plasma-polymerized hexamethyldisiloxane film demonstrated effective antibacterial and antiviral properties without cytotoxic effects on human cells. This combination creates functional materials with potential applications in medical settings. As antimicrobial resistance continues to grow, NTP technology offers a powerful, economical, and versatile approach to decontamination across various settings, from healthcare facilities to everyday environments. Its ability to effectively neutralize pathogens while preserving the integrity of sensitive materials positions it as a valuable tool in our ongoing fight against infectious diseases.