To Aid in the War Against COVID-19, Prof. Bagnato Develops a UV Squeegee for Hospital Disinfection

Vanderlei Salvador Bagnato is a full professor at the University of São Paulo (USP) and the director of the Institute of Physics of São Carlos of USP. Bagnato and his team have developed a UV squeegee that has begun to be used to decontaminate hospital floors of bacteria and viruses (including SARS-CoV-2). His research group is also studying the use of a UV technique for the treatment of pharyngotonsillitis and throat disinfection in intubated patients. Learn more about this Brazilian researcher in this article.

Updated on May 18, 2020

A scientist looking at petri dishes
workers using the UV squeegees developed by Salvador Bagnato

Interview conducted on 4/10/20

“Nature does not choose topics. It is man who chooses topics, who has divided nature into different areas. Nature is nature, and it is unique...the laws of nature are the same for everything. So you can't imagine different sciences to explain nature. We are the ones who have divided it to simplify things.” (Prof. Vanderlei Salvador Bagnato)

1. Why did you decide to pursue two undergraduate degrees: one in physics and one in materials engineering?

It was a matter of personal choice. I've always liked the hard sciences, although that has never stopped me from looking at how to apply the hard sciences to the life sciences. When applying for college, I took college admissions tests for two universities: the University of São Paulo (USP) and the Federal University of São Carlos (UFSCar). As I passed both entrance exams, I thought I could try to attend both universities simultaneously. And that's what I did. From 1977 to 1981, I completed a bachelor's degree in physics from USP and a bachelor's degree in materials engineering from UFSCar, both in the same city. The curriculum of each course of study helped with the curriculum of the other course of study.

2. What made you interested in applying physics and materials engineering to medical sciences fields?

I am a physicist and completed my PhD at MIT in Boston from 1983 to 1987. During that time, I saw applications of physics in medicine, mainly of optics in medicine, that were not yet being commonly implemented in Brazil. In Brazil, the so-called biophysics field was different from the biophysics field that I saw in the USA. This difference got me interested. But I didn't start working on it right away. No, it wasn't until 1994 that I started working with the possibility of using optical techniques for the diagnosis and treatment of cancer. So, five years later.

I had a slightly accelerated career path. After I returned from earning my doctorate, I became an Associate Professor at USP in 1989 and then a Full Professor at USP in 1991. When you become a Full Professor, you end up having more peace of mind and are able to explore the areas that you find most interesting. However, I never left my primary areas. Atomic physics and optical spectroscopy have always been with me, and they are the areas that actually provide the basis for medical applications. If you read the work I did at that time, you will see that it always had a physical aspect to explain the phenomena observed in the areas of cancer treatment and diagnosis.

3. How did your previous work prepare you for the development of the UV squeegee?

During my entire career, I have been working with interactions between electromagnetic radiation and matter. Since I earned my doctorate, the focus of my academic career has been the interactions between atoms/molecules and light. Sometimes, the effects of light on atoms and molecules help in certain things. For example, if you want to destroy a molecule to produce different things, you can use light for this.

UV light is a form of electromagnetic radiation with very high energy. When it interacts with atoms and molecules (mainly biomolecules, which have large concentrations of electrons and atoms), it can destroy them, fragment them. So if you want to destroy microorganisms, or even cells, UV radiation is a very interesting option. I have been working with UV radiation for cleaning, mainly for food decontamination. Recently, our research group, together with researchers from Canada, published an article in Nature Communications about the use of UV to decontaminate organs for transplantation; in this case, the liquid circulating through the organ to be transplanted is continuously decontaminated. So, you can see that I've been involved with this for a few years.

At this time of COVID-19 in which we are living, it is necessary to create instruments that are easy to use and that allow us to destroy microorganisms such as viruses and bacteria. Thus, making a little squeegee seemed interesting. After all, we must not forget that the floor is one of the most contaminated parts of an environment. Where are contaminants? Contaminants are anywhere that people touch a lot, e.g., handrails, counters and the floor – the floor especially, because everything that happens in an environment ends up on the floor and is then carried on shoes. So I had the idea to make this UV squeegee.

In fact, four years ago, I made a device similar to the UV squeegee (the Surface UV®) in partnership with the company MM Optics in Brazil. This portable hand-operated device is already being marketed. It can be used on countertops, handrails, tables, beds, instruments...because in an environment where you have patients, everything is constantly being contaminated, and not everything can be cleaned up after each patient uses it.

What I have now done is to expand the use of this type of device to the floor. By cleaning the floor with the UV squeegee, we can achieve very good decontamination – both bacterial and viral decontamination. UV is very good for viruses because it destroys both the protein and genetic loads. That is, it not only takes away the functionality of the virus but also destroys its reproductive capacity; the virus life cycle then stops there.

There is another version of this surface cleaner used in Germany and China; the difference is that that version works only with UVA. However, UVA is not enough when it comes to bacteria and viruses. For these contaminants, you also need to have the B and C components of UV light. I've done studies published in American journals with these squeegees that have shown that we need to use a broader UV spectrum, not just UVA. And then you also need to have safety mechanisms such that the squeegee stops working if the person is not near the squeegee or if the person turns the squeegee up to look at the light. This little squeegee is useful, and its use has already been approved here in Brazil.

4. Describe the day your group first saw a UV squeegee being used in a hospital. How did you feel?

We were very happy. I manufactured about 50 of these squeegees for hospital use, which were donated to Catholic hospitals and other hospitals. Now I've made a very cheap plastic version, rather than metal, so that we can donate the squeegees to some institutions. The company MM Optics together with NSF has made a version with stainless steel, which is already in the process of being marketed. They have committed themselves to make low-cost and affordable products that correspond to the economic reality we live in.

5. Do you have plans to export this device?

Yes, but that depends on interest and advertisement. Companies are facing a very critical time in Brazil because they are being forced to dismiss employees and are working with small numbers of people. But there is no doubt that we are interested in exporting the device. Currently, companies are not able to find the channels for this to happen, but if a large company in the U.S. were willing to import both the small and the large squeegee, they could certainly import them. One of the advantages for companies that want to import these products is that Brazil does not charge them the 30% export tax rate. That is, those who want to import the products can buy them at a price 30% cheaper than the price at which they are sold in Brazil.

6. Not to mention that the value of the dollar is much higher than it was before, which makes the devices much more affordable. For example, if today the product costs 100 BRL in Brazil, it could be exported to the U.S. for ~20 USD.

Correct! I see that in America, there are a lot of people making robots for this purpose; however, in essence, all of these robots are limited, because for you to really clean a surface, you have to have a certain amount of energy delivered to the surface. That's why we recommend a slow squeegee speed so that you can deliver the correct dose of energy and eliminate microorganisms.

7. What are the main barriers and opportunities regarding the implementation of UV technology in Brazilian hospitals?

Brazilian hospitals use little UV light. The use of UV is older than the use of insecticides; UV has been used since the late nineteenth century. But as we've had very good advances in the chemical industry, detergents and disinfectants have begun to dominate our lives, and UV decontamination has practically been abandoned over the past four decades. But UV has been used in the past, mainly for cleaning instruments. There was a time when dentists had small UV chambers for decontamination of dental instruments. Nowadays, almost every office has an autoclave.

However, we are now living a slightly different reality. We don't just need instrumental sterilization. The reality is that we now have resistant microorganisms and new microorganisms in the environment, on objects. Not all contaminated things can go into the autoclave or be treated with chemicals. Imagine if I had to put disinfectant on the hallway floor of a hospital; people would end up having reactions, because not everyone can tolerate chemicals. So, now there is a need for this kind of device. Also, the UV squeegee will kill microorganisms wherever it passes, but without harming the environment; i.e., it is "environmentally friendly". Because UV decontamination involves no chemicals or byproducts, it is an excellent option.

8. Currently, here in the U.S., people are so worried about the COVID-19 pandemic that they clean the cart with disinfectant wipes when they arrive at the supermarket and then disinfect everything they purchased when they get home. It takes a long time to disinfect everything before storing it in the pantry, not to mention that it is a waste of wipes. I think it would be very interesting for hospitals, dentist's offices and schools to use this UV squeegee or the Surface UV® device.

If the device is well used, yes. I'm a member of the National Academy of Sciences in the U.S. Last year, in 2019, I went to the meeting, and there was a discussion about resistant bacteria, which is one of the areas in which I work. I also wrote an article here in Brazil for a journal about the parallel between global warming and microorganism-related issues. The problems of resistant organisms and new microorganisms are as serious as global warming. The only difference is that much less emphasis is given to them than to global warming. During the meeting, I said that while global warming will kill people in 100 years, microorganisms could kill them in a week. That's what we're living now, isn't it?

And it's amazing that in cities such as São Paulo and Venice, pollution has been drastically reduced in just 30 days of lockdown. All we had to do was to stop using cars and throwing garbage into the atmosphere for all that to stop. This does not happen with microorganisms. And this isn't the last pandemic we're going to live in. The numbers of bacteria and fungi resistant to known drugs are increasing every day, and the microorganisms are becoming increasingly resistant.

I am very concerned about hospital-acquired pneumonia because today, it no longer responds to antibiotics. The number of people who die in hospitals after having acquired resistant pneumonia is increasing rapidly. You hear all the time about someone who was in the hospital and died of an infection acquired inside the hospital. And resistant pneumonia is one of the worst.

From now on, we will live in a new era, an era in which we will have to coexist with microorganisms resistant to known drugs; that is, we will be living in bad times. So technology has to get into all of this. That is why we work with optical techniques, because it has already become clear that, in the next decade, we will lack new antibiotics that are capable of fighting these resistant microorganisms.

This will happen not because of the lack of research in this area but because the current state of technology cannot solve the problem so fast. Only other techniques will be able to do this. It is not a question of making a new generation of antibiotics; rather, it is about changing our concept of how we combat microorganisms.

The largest pharmaceutical companies, including those in the U.S., have already declared that they cannot offer a solution for resistant bacteria in the next 5 or 6 years. And the bacteria are advancing, because the more antibiotics we use, the more resistant they get. Nowadays, we already have a number of resistant bacteria that have reached fish because we use a lot of antibiotics. Antibiotics go into rivers, and from there the fish themselves can no longer respond to certain antibiotics. The same goes for antifungals. So the problem is getting complicated. It's not just about COVID-19. No, we'll still have to live through other bad times in the future.

9. What other devices do you have in mind that could help combat SARS-CoV-2 or other microorganisms, including resistant bacteria?

We have a project that uses photodynamic action, where the person inhales a substance and we illuminate this substance inside the person's body, thus activating the drug, which begins to kill microorganisms that are in the airways. This is an ongoing project. We have already done demonstrations on animals, and we are starting the testing phase in humans.

This is a project in partnership with the U.S. (Texas) and Canada (Toronto). We're accelerating this project because I think people who escape this pandemic may have respiratory complications. I have seen a study in which 30% of people were predicted to have other respiratory complications from this as consequences of the severe and long-term inflammation they are having in the bronchi. Then, they'll have pneumonia more frequently. So we're going to have to be quick and use new techniques. This is one of the studies we are doing in our labs that hasn't stopped during this COVID-19 crisis. Students and postdocs are working because we want to move quickly.

10. So that is what you and your researchers are currently focusing on?

We're not worried about making any more respirators. Our concern is to shorten the time patients would be on respirators. There are some new drugs coming from the United States that are good; they are being tested and hold great promise. But we need more techniques, because not everyone will respond satisfactorily to these drugs, as always happens. So we need to have alternatives.

I am writing an article for the Brazilian newspaper Folha de São Paulo whose title is "Beyond Ventilators and Masks". My concern is that soon we will have no more doctors or nurses because they will be infected and sick. So we really need to come up with technology that cleans hospitals and protects the professionals more than they have been protected thus far.

The first victims are health professionals, as they are the ones who are most exposed; see, for example, what is happening in China, the United States, and Brazil. So the concerns now are how to clean the environment, how to protect the professionals, and how to decrease the duration of the illness in patients.

11. Who most influenced you?

My motivation came when I was still in the U.S. and participated in conferences of the Optical Society of America. In these conferences, there were sessions dedicated to the application of optics to health problems. Back then, my biggest interest was cancer. Some American and European researchers who were working with both diagnostic and treatment techniques motivated me a lot in the 1990s.

As for microbiological control, my interest in this is more recent. Currently, I am part of a team that has helped contribute to the evolution of the state of the art of optical decontamination techniques. The technique of photodynamic decontamination has arisen only recently. We are one of the first groups to use this technique for HPV infection in women, which is a viral infection that can evolve into cervical cancer. We have also contributed a lot to the use of this technique for the treatment of fungal infections and, in the mouth, for the treatment of periodontitis. In fact, this technique has been used in dentistry in Brazil on a regular basis.

Now we're studying throat disinfection. I have conducted a very beautiful study on a technique in which a child sucks a lollipop or tablet that deposits a substance onto bacterial plaques in the throat; when the substance is illuminated, the infection is eliminated in less than 10 hours. The technique is a treatment for pharyngotonsillitis, which is a bacterial throat infection. We have already done a lot of work on the subject demonstrating its effectiveness. We are already at the end of a clinical trial here in Brazil; it took me two years to get approval from the research ethics committee, but the research is evolving, and everything is going really well.

I have also conducted a study on disinfection of intubated patients with a technique in which an optical fiber is inserted together with the endotracheal tube. In this case, the endotracheal tube itself is transformed into a bactericide, and photodynamic action is used to inactivate viruses and bacteria; that is, we use visible light to illuminate the internal parts of the body, thus preventing the formation of bacterial biofilms and preventing the occurrence of pneumonia associated with mechanical ventilation. This is a study that should be published in the Proceedings of the National Academy of Sciences. I also think this technique will help decrease the duration of patient intubation. This will be beneficial because increasing the duration of intubation increases the chance of infection in the intubated patient. Because of the risk of infection, intubated patients must simultaneously be given antibiotics.

12. I found the technique with the lollipop to be a very interesting option for treatment of bacterial infections such as Streptococcus pyogenes infection.

This is the most common infection in the throats of children and adults and is a cause of high antibiotic consumption, which makes other bacteria more resistant. Nowadays, we even have adults who die from throat infection

13. What was the most productive moment of your research career? Is that moment now?

I don't know what to say. I'm a passionate person, so for me every period is intense, you know? I turned 60 recently, but as some other scientists would also say, I never get tired of being useful. All the time we're thinking about how to turn science into technology and about how science can help people, how it can generate wealth...I can't tell which periods have been better or worse. I think I'll take stock of my life before I die, though. [laughs]

14. What else would you like to tell us?

We have a 24-hour TV channel showing how to do science, describing science, showing labs, showing how things happen. It might be one of the few TV channels in the world that shows the inside of a research lab. We also have a YouTube channel. If you go to the website of the Center for Optical and Photonic Research (CEPOF), one of FAPESP's centers, and click on "Diffusion," you will find the various ways in which we disseminate our work. We began teaching online on our channel 15 years ago, when distance education was still a dream.

15. All of this is very interesting! You and your group are so advanced and prepared for the situation we are going through right now.

Yes. We even teach online lab classes. We send kits to children in the mail, and they can take the lab classes online. On our website, there is a program involving educational kits that have also been used by MIT to train students in their summer program.

16. Is there any legislation you would change to improve the way science is done in your field?

There always is. We have bureaucracies all over the world. Scientists spend a lot of time dealing with rules regarding resource use. We have a lot of difficulty, and sometimes we need to create alternative paths. It's still very inconvenient the way we're pressured. For example, forcing a researcher to choose something based on price rather than on quality is not an intelligent decision when it comes to science.

17. To conclude our interview, what special message would you like to pass on?

I am a Christian, and at the academy at the Vatican, I have initiatives with the Pope. We use scientific education as an element of social integration. The academy at the Vatican has just over 50 members, of whom 38 have received Nobel Prizes. The next plenary session of the academy, which is supposed to be in October 2020 but is likely to be postponed, will be titled "Science Education as an Ingredient of Social Integration." Basically, we believe that it is of no use for us to continue providing things to children if we do not teach them the basics of science so that they can be the very protagonists of social needs, whether on the African continent, in Latin America, or anywhere else.

Posted on 05/18/2020

Thanks to Flavia Jaszczak for conducting the interview, Sheila Vieira for the interview preparation, transcription, and translation, and Molly Amador for English editing.

About Dr. Bagnato
Professor Vanderlei Salvador  Bagnato

Dr. Vanderlei Salvador Bagnato simultaneously completed his Bachelor of Physics (University of São Paulo, USP) and Bachelor of Materials Engineering (Federal University of São Carlos, UFSCar) degrees in 1981 and earned a doctorate degree in physics from the Massachusetts Institute of Technology (MIT) in 1987. He is currently a full professor at USP and the director of the Institute of Physics of São Carlos of USP. He has published nearly 700 articles in specialized journals, written 29 book chapters, published 7 books, and received numerous awards and honors. He has also advised students on more than 100 master's theses and doctoral dissertations in the areas of physics, dentistry, and medicine. Bagnato works in the Department of Atomic Physics and Applications of Optics in Health Sciences. Specifically, he studies cold atoms, Bose-Einstein condensates, and photodynamic actions in the contexts of cancer and microbiological control. He is a member of the Brazilian Academy of Sciences, The World Academy of Sciences, the Pontifical Academy of Sciences of the Vatican, and the National Academy of Sciences. He coordinates the Center for Research in Optics and Photonics (CEPOF), which integrates basic and applied sciences. He is also engaged in several pursuits regarding technological innovation and dissemination of scientific findings.

Some of Dr. Bagnato's publications regarding the subjects discussed:

  1. Corrêa, Thaila Q., Inada, Natalia M., and Bagnato, Vanderlei S. Surface UV® na descontaminação de superfícies e instrumentos [Surface UV® for surface and tool decontamination]. Controle Microbiológico com Ação Fotodinâmica, 1st edition, São Carlos: Compacta Gráfica e Editora, 2017, v.1, p. 273-286.
  2. Corrêa, Thaila Q., Blanco, Kate C., Inada, Natalia M., Hortenci, Maisa F., Costa, Angela A., Silva, Evaine S., Gimenes, Patricia P. C., Pompeu, Soraya, de Holanda E Silva, Raphael L., and Figueiredo, Walter M., and Bagnato, Vanderlei S. Manual Operated Ultraviolet Surface Decontamination for Healthcare Environments, Photomedicine and Laser Surgery, vol. 35, no. 12, pp. 666-671, 2017. DOI: 10.1089/pho.2017.4298
  3. Bagnato, Vanderlei S. and Aquino Junior, Antonio E. Fundamentos da luz, da fototerapia e de suas modernas aplicações na podologia [Fundamentals of light, phototherapy, and their modern applications in podiatry]. Fundamentos e aplicações da laserterapia na podologia, 1st edition, São Carlos: Compacta Gráfica e Editora, 2018, v.1, p. 13-37.
  4. Corrêa, Thaila Q., Blanco, Kate C., Garcia, Érica B., Perez, Shirly, M. L., Chianfrone, Daniel J., Morais, Vinicius S., and Bagnato, Vanderlei S. Effects of ultraviolet light and curcumin-mediated photodynamic inactivation on microbiological food safety: a study in meat and fruit. Photodiagnosis and Photodynamic Therapy, vol. 30, 2020, 101678.
  5. Corrêa, Thaila Q., Blanco, Kate C., Soares, Jennifer, Natalia M., Kurachi, Cristina, Golim, Marjorie A., Deffune, Elenice, and Bagnato, Vanderlei. Photodynamic inactivation for in vitro decontamination of Staphylococcus aureus in whole blood. Photodiagnosis and Photodynamic Therapy, vol. 28, pp. 58-64, 2019. DOI: 10.1016/j.pdpdt.2019.08.013.
  6. Galasso, M., Feld, J.J., Watanabe, Y. et al. Inactivating hepatitis C virus in donor lungs using light therapies during normothermic ex vivo lung perfusion. Nature Communications, vol. 10, 481 (2019).
  7. Zangirolami, A.C., Dias, L.D., Blanco, K.C., Vinagreiro, C.S., lnada, N.M., Arnaut, L.G., Pereira, M.M., and Bagnato, V.S; Avoiding Ventilator-Associated Pneumonia: Curcumin-Functionalized Endotracheal Tube and Photodynamic Action. To be published in the Proceedings of the National Academy of Sciences of the United States of America, 2020.
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