Kaiming Ye e Guy German da Binghamton University, State University of New York desenvolveram uma máquina para desinfetar equipamentos de proteção individual, como máscaras faciais. Crédito: Binghamton University, State University of New York
A pesquisa estabelece as bases para os padrões de saúde sobre o que oferece a verdadeira esterilização ultravioleta.
Quando o[{” attribute=””>COVID-19 pandemic emerged in early 2020, ultraviolet (UV) radiation became one of the go-to methods for preventing the spread of the SARS-CoV-2 virus, along with facemasks, hand sanitizer, and social distancing.
One problem: There was little research showing what UV dosage kills the virus. What wavelength? How long? And could UV systems be installed in public places such as airports, bus terminals, train stations, and stores without causing long-term harm to people?
In a newly published research study, scientists from Binghamton University’s Thomas J. Watson College of Engineering and Applied Science answer many of those questions and lay the foundation for health standards about what offers true disinfection.
The paper, titled “Systematic evaluating and modeling of SARS-CoV-2 UVC disinfection” and published in the journal Scientific Reports, was written by Distinguished Professor Kaiming Ye, chair of the Department of Biomedical Engineering; BME Associate Professor Guy German and BME Professor Sha Jin, along with PhD student Sebastian Freeman; Zachary Lipsky, PhD ’21; and Karen Kibler from the Biodesign Institute at Arizona State University.
A ideia da pesquisa surgiu quando a escassez de equipamentos de proteção individual (EPI) no início da pandemia inspirou funcionários da Ye, German e Binghamton University a construir rapidamente estações de desinfecção UV para hospitais na região, para que máscaras N-95 e outros itens pudessem ser reutilizado.
“Há muitas pesquisas sobre dosagens de UV na literatura científica, mas não de forma sistemática”, disse Ye. “Quando começamos este projeto, realmente não havia dados ou experimentos feitos porque a pandemia aconteceu muito rapidamente.”
Ye e German receberam financiamento para tirar suas dúvidas por meio de uma doação em meados de 2020 por US$ 182.728 da National Science Foundation. A equipe de Binghamton adicionou um retrovírus semelhante ao SARS-CoV-2 a três meios diferentes (um meio de cultura de células, água e uma recriação artificial de saliva humana) e os expôs a três comprimentos de onda diferentes na faixa UVC. UVC mata vírus e outros microorganismos danificando seus[{” attribute=””>DNA and RNA, which are the bioorganic building blocks for life.
Associate Professor Guy German, left, and Distinguished Professor Kaiming Ye, chair of the Department of Biomedical Engineering, have new research that offers provable standards for ultraviolet disinfection. Credit: Jonathan Cohen.
“The disinfection efficiencies are greatly influenced by the media where the virus is,” Ye said. “We used the same dosage, the same light intensity, and the same wavelengths when the virus was suspended in saliva, water, and a cell-culture medium, but the efficiency was completely different.”
The best results during the study came from a range of 260 to 280 nanometers, which is commonly used in LED UVC lights. Wavelengths below 260 nanometers can be deployed only in unoccupied spaces because they can damage human skin and eyes.
“There are so many companies that are purporting to say their products completely disinfect and are completely safe,” German said. “However, in this article, we demonstrate that both far (222 nanometers) and regular UVC light (254 nanometers) degrade the mechanical integrity of the stratum corneum, the skin’s top layer, causing higher likelihood of cracking. That means nasty bacteria and other microorganisms can get into and potentially infect your skin.”
Based on the results of the research, Ye and German have designed an LED light disinfection system that should cause less damage to human skin. They are doing additional testing before applying for a patent on it.
“We are waiting for the data, and then we are pretty much finished. We know it will work,” Ye said.
Also, the Binghamton team found that two amino acids (L-tryptophan and L-tyrosine) and a vitamin (niacinamide) are strong absorbers of UVC, and that discovery could lead to lotions that would block exposure and prevent skin damage if UVC disinfection becomes more prevalent in public spaces.
Ye believes the most important part of this research is that it offers a scientific basis for standardizing and regulating claims from manufacturers of UV disinfectant devices.
“The system we came up with can become the model for anybody who wants to standardize the dosage,” he said. “This is how to determine the eradication of SARS-CoV-2 using UVC — maybe also SARS-CoV-3, SARS-CoV-4, SARS-CoV-5. We hope we never get there, but we need to be prepared.”
Reference: “Systematic evaluating and modeling of SARS-CoV-2 UVC disinfection” by Sebastian Freeman, Karen Kibler, Zachary Lipsky, Sha Jin, Guy K. German and Kaiming Ye, 7 April 2022, Scientific Reports.
DOI: 10.1038/s41598-022-09930-2
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