The no-stick technology invented by Professor Kripa Varanasi and David Smith SM ’11, initially commercialized as LiquiGlide in 2012, went viral for its uncanny ability to make materials that stick to their containers — think ketchup, cosmetics, and toothpaste — slide out with ease.

Now, the company that brought you Colgate no-stick toothpaste is moving into the medical space, and the applications could improve millions of lives. The company, which recently rebranded as the Arnasi Group, has developed an ambitious plan to launch three new biomedical products over the next four years.

The first of those products, called Revel, is a deodorizing lubricant designed for ostomy pouches, which are used by individuals to collect bodily waste after digestive system surgeries. Up to 1 million people rely on such pouches in the United States. Ostomy pouches must be emptied multiple times per day, and issues resulting from sticking or clogging can cause embarrassing, time-consuming situations for the people relying on them.

Arnasi’s deodorizing lubricant can prevent clogging and simplify the ostomy pouch cleaning process. Unlike other options available, one application of its lubricant works for the entire day, the Arnasi team says, and they designed a single unit dose that fits in your pocket for added convenience.

An ostomy pouch “significantly impacts a person’s lifestyle,” Varanasi says. “They need to keep it clean, and they need to use it at all times. We are solving a very important problem while helping people by giving their dignity and lifestyles back.”

Revel, Arnasi’s FDA-registered product, officially launched this month, and it has already received promising feedback from nurses and patients.

Margaret is a nurse who relies on an ostomy pouch herself and cares for patients who need them after receiving colostomies and ileostomies. She received samples of Revel at a recent conference and says it could dramatically improve both her and her patients’ lives.

“These pouches need to be emptied frequently, and sometimes that’s very difficult to do,” she says. “This particular product makes everything slide out without any problems at all, and it’s a wonderful improvement. It also lasts long enough to empty the pouch three to four times, which is great because you don’t have to carry a bunch of this stuff around.”

Margaret’s experience echoes feedback Arnasi’s team has heard from many others.

“When we showed it to the nurses, they were blown away with the product,” says Arnasi CEO Dan Salain. “They asked us to get this product out to the market as fast as we could, and so that’s what we’re doing.”

Arnasi’s next medical products will be used to prevent biofilm and bacterial infections caused by implants and catheters, and will also help people with cystic fibrosis.

“We want to create products that really help people,” Salain says. “Anything that’s implantable in the body, whether it’s a catheter, a hip, knee, or joint replacement, a breast implant, a bladder sling — those things lend themselves to our technology.”

From packages to patients

Varanasi initially developed Arnasi’s liquid-impregnated surface technology with Smith, Arnasi’s co-founder and current CTO, when Smith was a graduate student in Varanasi’s lab. The research was initially funded by the MIT Energy Initiative and the MIT Deshpande Center to work on solid-liquid interfaces with broad applications for energy, water, and more.

“There’s this fundamental friction constraint called the no-slip boundary condition between a liquid and a solid, so by creating a new surface in which we can infuse a liquid that is less viscous, we can now get the product to easily slide on surfaces,” Varanasi explains. “That aha moment meant we could get around a fundamental constraint in fluid dynamics.”

Still, sticky surfaces are everywhere, and the scientific co-founders had to decide where to apply their technology first. Shortly after the invention, Varanasi was at home trying to decide on the best application when he saw his wife across the kitchen table trying to get honey out of a bottle. It was another aha moment.

Soon after, Varanasi’s team entered the MIT $100K Entrepreneurship Competition. The competition — and the corresponding videos of ketchup and other materials sliding out their bottles with ease — created a media storm and a frenzy of attention.

“The press exploded,” Varanasi says. “For three months, my phone didn’t stop ringing. My group website crashed. There was a lot of market pull and in response, we founded the company.”

Arnasi, still operating as LiquiGlide, licensed the intellectual property from MIT’s Technology Licensing Office and eventually signed large deals with some of the world’s biggest consumer packaged goods companies, who used it to create products like fully recyclable toothpaste.

“There is so much waste just because we can't get all of the product, be it food, cosmetics, or medical products, out of containers,” Varanasi says. “Fifty billion-plus packages are sold every year, and 5 to 10 percent of product is left behind on average. So, you can imagine the CO₂ footprint of the wasted product. And even though a lot of this is in recyclable packaging, they can’t be recycled because you need to wash out all the product. The water footprint of this is huge, not to mention the wasted product.”

While all of that was going on, Arnasi’s team was also looking into the biomedical space. For instance, Varanasi’s lab previously showed the technology could be used to prevent occlusion from blood clots and thrombosis and reduce biofilm formation, among other applications.

After studying the industry and speaking with patients and nurses, Arnasi realized a better lubricant for ostomy pouches could improve millions of people’s lives.

“Stool accumulates in these pouches outside of people’s bodies, and they need to empty it up to eight times a day,” explains Brienne Engel, Arnasi’s director of business development. “That process has a lot of challenges associated with it: It can be difficult to drain, leaving a lot of mass behind, it takes a long time to drain, so you can spend a long time in a restroom trying to clear out your pouch, and then there’s something called pancaking that can push the pouch off the [surgical opening], introducing issues like leakage, odor, and failure of the ostomy pouching system.”

Ostomy and beyond

Arnasi’s ostomy lubricant, Revel, is the first non-water-based solution on the market, and as-yet unpublished third-party testing has shown it allows for faster, more complete pouch drainage, along with other benefits.

“A lot of the existing brands treat their consumers like patients, but what we’ve found is they want to be treated like people and have a consumer experience,” Salain says. “The magic we saw with our toothpaste product was people got this amazing consumer experience out of it, and we wanted to create the same thing with Revel.”

Now Arnasi is planning to use its technology in medical products for skin infections, cystic fibrosis, and in implantable catheters and joint replacements. Arnasi’s team believes those last two use cases could prevent millions of deadly infections.

“When people are getting hemodialysis catheters, they have a 33 percent risk of developing infections, and those that do get those infections have a 25 percent chance of dying from them,” Engel says. “Taking our underlying technology and applying it to catheters, for example, imparts anti-biofilm properties and also prevent things like thrombosis, or blood clotting on the outside of these catheters, which is a problem in and of itself but also provides a space for bacteria to seed.”

Ultimately, Varanasi’s team is balancing making progress on its biomedical applications while exploring other avenues for its technology — including energy, manufacturing, and agriculture — to maximize its impact on the world.

“We think of this as a company with many companies within it because of all the different areas that it can impact. Liquid-solid interfaces are ubiquitous, viscous products are everywhere, and deploying this technology to solve difficult problems has been a dream,” Varanasi says. “It’s a great example of how MIT technology can be used for the benefit of humankind.”

The no-stick technology invented by Professor Kripa Varanasi and David Smith SM ’11, initially commercialized as LiquiGlide in 2012, went viral for its uncanny ability to make materials that stick to their containers — think ketchup, cosmetics, and toothpaste — slide out with ease.

Now, the company that brought you Colgate no-stick toothpaste is moving into the medical space, and the applications could improve millions of lives. The company, which recently rebranded as the Arnasi Group, has developed an ambitious plan to launch three new biomedical products over the next four years.

The first of those products, called Revel, is a deodorizing lubricant designed for ostomy pouches, which are used by individuals to collect bodily waste after digestive system surgeries. Up to 1 million people rely on such pouches in the United States. Ostomy pouches must be emptied multiple times per day, and issues resulting from sticking or clogging can cause embarrassing, time-consuming situations for the people relying on them.

Arnasi’s deodorizing lubricant can prevent clogging and simplify the ostomy pouch cleaning process. Unlike other options available, one application of its lubricant works for the entire day, the Arnasi team says, and they designed a single unit dose that fits in your pocket for added convenience.

An ostomy pouch “significantly impacts a person’s lifestyle,” Varanasi says. “They need to keep it clean, and they need to use it at all times. We are solving a very important problem while helping people by giving their dignity and lifestyles back.”

Revel, Arnasi’s FDA-registered product, officially launched this month, and it has already received promising feedback from nurses and patients.

Margaret is a nurse who relies on an ostomy pouch herself and cares for patients who need them after receiving colostomies and ileostomies. She received samples of Revel at a recent conference and says it could dramatically improve both her and her patients’ lives.

“These pouches need to be emptied frequently, and sometimes that’s very difficult to do,” she says. “This particular product makes everything slide out without any problems at all, and it’s a wonderful improvement. It also lasts long enough to empty the pouch three to four times, which is great because you don’t have to carry a bunch of this stuff around.”

Margaret’s experience echoes feedback Arnasi’s team has heard from many others.

“When we showed it to the nurses, they were blown away with the product,” says Arnasi CEO Dan Salain. “They asked us to get this product out to the market as fast as we could, and so that’s what we’re doing.”

Arnasi’s next medical products will be used to prevent biofilm and bacterial infections caused by implants and catheters, and will also help people with cystic fibrosis.

“We want to create products that really help people,” Salain says. “Anything that’s implantable in the body, whether it’s a catheter, a hip, knee, or joint replacement, a breast implant, a bladder sling — those things lend themselves to our technology.”

From packages to patients

Varanasi initially developed Arnasi’s liquid-impregnated surface technology with Smith, Arnasi’s co-founder and current CTO, when Smith was a graduate student in Varanasi’s lab. The research was initially funded by the MIT Energy Initiative and the MIT Deshpande Center to work on solid-liquid interfaces with broad applications for energy, water, and more.

“There’s this fundamental friction constraint called the no-slip boundary condition between a liquid and a solid, so by creating a new surface in which we can infuse a liquid that is less viscous, we can now get the product to easily slide on surfaces,” Varanasi explains. “That aha moment meant we could get around a fundamental constraint in fluid dynamics.”

Still, sticky surfaces are everywhere, and the scientific co-founders had to decide where to apply their technology first. Shortly after the invention, Varanasi was at home trying to decide on the best application when he saw his wife across the kitchen table trying to get honey out of a bottle. It was another aha moment.

Soon after, Varanasi’s team entered the MIT $100K Entrepreneurship Competition. The competition — and the corresponding videos of ketchup and other materials sliding out their bottles with ease — created a media storm and a frenzy of attention.

“The press exploded,” Varanasi says. “For three months, my phone didn’t stop ringing. My group website crashed. There was a lot of market pull and in response, we founded the company.”

Arnasi, still operating as LiquiGlide, licensed the intellectual property from MIT’s Technology Licensing Office and eventually signed large deals with some of the world’s biggest consumer packaged goods companies, who used it to create products like fully recyclable toothpaste.

“There is so much waste just because we can't get all of the product, be it food, cosmetics, or medical products, out of containers,” Varanasi says. “Fifty billion-plus packages are sold every year, and 5 to 10 percent of product is left behind on average. So, you can imagine the CO₂ footprint of the wasted product. And even though a lot of this is in recyclable packaging, they can’t be recycled because you need to wash out all the product. The water footprint of this is huge, not to mention the wasted product.”

While all of that was going on, Arnasi’s team was also looking into the biomedical space. For instance, Varanasi’s lab previously showed the technology could be used to prevent occlusion from blood clots and thrombosis and reduce biofilm formation, among other applications.

After studying the industry and speaking with patients and nurses, Arnasi realized a better lubricant for ostomy pouches could improve millions of people’s lives.

“Stool accumulates in these pouches outside of people’s bodies, and they need to empty it up to eight times a day,” explains Brienne Engel, Arnasi’s director of business development. “That process has a lot of challenges associated with it: It can be difficult to drain, leaving a lot of mass behind, it takes a long time to drain, so you can spend a long time in a restroom trying to clear out your pouch, and then there’s something called pancaking that can push the pouch off the [surgical opening], introducing issues like leakage, odor, and failure of the ostomy pouching system.”

Ostomy and beyond

Arnasi’s ostomy lubricant, Revel, is the first non-water-based solution on the market, and as-yet unpublished third-party testing has shown it allows for faster, more complete pouch drainage, along with other benefits.

“A lot of the existing brands treat their consumers like patients, but what we’ve found is they want to be treated like people and have a consumer experience,” Salain says. “The magic we saw with our toothpaste product was people got this amazing consumer experience out of it, and we wanted to create the same thing with Revel.”

Now Arnasi is planning to use its technology in medical products for skin infections, cystic fibrosis, and in implantable catheters and joint replacements. Arnasi’s team believes those last two use cases could prevent millions of deadly infections.

“When people are getting hemodialysis catheters, they have a 33 percent risk of developing infections, and those that do get those infections have a 25 percent chance of dying from them,” Engel says. “Taking our underlying technology and applying it to catheters, for example, imparts anti-biofilm properties and also prevent things like thrombosis, or blood clotting on the outside of these catheters, which is a problem in and of itself but also provides a space for bacteria to seed.”

Ultimately, Varanasi’s team is balancing making progress on its biomedical applications while exploring other avenues for its technology — including energy, manufacturing, and agriculture — to maximize its impact on the world.

“We think of this as a company with many companies within it because of all the different areas that it can impact. Liquid-solid interfaces are ubiquitous, viscous products are everywhere, and deploying this technology to solve difficult problems has been a dream,” Varanasi says. “It’s a great example of how MIT technology can be used for the benefit of humankind.”

The no-stick technology invented by Professor Kripa Varanasi and David Smith SM ’11, initially commercialized as LiquiGlide in 2012, went viral for its uncanny ability to make materials that stick to their containers — think ketchup, cosmetics, and toothpaste — slide out with ease.

Now, the company that brought you Colgate no-stick toothpaste is moving into the medical space, and the applications could improve millions of lives. The company, which recently rebranded as the Arnasi Group, has developed an ambitious plan to launch three new biomedical products over the next four years.

The first of those products, called Revel, is a deodorizing lubricant designed for ostomy pouches, which are used by individuals to collect bodily waste after digestive system surgeries. Up to 1 million people rely on such pouches in the United States. Ostomy pouches must be emptied multiple times per day, and issues resulting from sticking or clogging can cause embarrassing, time-consuming situations for the people relying on them.

Arnasi’s deodorizing lubricant can prevent clogging and simplify the ostomy pouch cleaning process. Unlike other options available, one application of its lubricant works for the entire day, the Arnasi team says, and they designed a single unit dose that fits in your pocket for added convenience.

An ostomy pouch “significantly impacts a person’s lifestyle,” Varanasi says. “They need to keep it clean, and they need to use it at all times. We are solving a very important problem while helping people by giving their dignity and lifestyles back.”

Revel, Arnasi’s FDA-registered product, officially launched this month, and it has already received promising feedback from nurses and patients.

Margaret is a nurse who relies on an ostomy pouch herself and cares for patients who need them after receiving colostomies and ileostomies. She received samples of Revel at a recent conference and says it could dramatically improve both her and her patients’ lives.

“These pouches need to be emptied frequently, and sometimes that’s very difficult to do,” she says. “This particular product makes everything slide out without any problems at all, and it’s a wonderful improvement. It also lasts long enough to empty the pouch three to four times, which is great because you don’t have to carry a bunch of this stuff around.”

Margaret’s experience echoes feedback Arnasi’s team has heard from many others.

“When we showed it to the nurses, they were blown away with the product,” says Arnasi CEO Dan Salain. “They asked us to get this product out to the market as fast as we could, and so that’s what we’re doing.”

Arnasi’s next medical products will be used to prevent biofilm and bacterial infections caused by implants and catheters, and will also help people with cystic fibrosis.

“We want to create products that really help people,” Salain says. “Anything that’s implantable in the body, whether it’s a catheter, a hip, knee, or joint replacement, a breast implant, a bladder sling — those things lend themselves to our technology.”

From packages to patients

Varanasi initially developed Arnasi’s liquid-impregnated surface technology with Smith, Arnasi’s co-founder and current CTO, when Smith was a graduate student in Varanasi’s lab. The research was initially funded by the MIT Energy Initiative and the MIT Deshpande Center to work on solid-liquid interfaces with broad applications for energy, water, and more.

“There’s this fundamental friction constraint called the no-slip boundary condition between a liquid and a solid, so by creating a new surface in which we can infuse a liquid that is less viscous, we can now get the product to easily slide on surfaces,” Varanasi explains. “That aha moment meant we could get around a fundamental constraint in fluid dynamics.”

Still, sticky surfaces are everywhere, and the scientific co-founders had to decide where to apply their technology first. Shortly after the invention, Varanasi was at home trying to decide on the best application when he saw his wife across the kitchen table trying to get honey out of a bottle. It was another aha moment.

Soon after, Varanasi’s team entered the MIT $100K Entrepreneurship Competition. The competition — and the corresponding videos of ketchup and other materials sliding out their bottles with ease — created a media storm and a frenzy of attention.

“The press exploded,” Varanasi says. “For three months, my phone didn’t stop ringing. My group website crashed. There was a lot of market pull and in response, we founded the company.”

Arnasi, still operating as LiquiGlide, licensed the intellectual property from MIT’s Technology Licensing Office and eventually signed large deals with some of the world’s biggest consumer packaged goods companies, who used it to create products like fully recyclable toothpaste.

“There is so much waste just because we can't get all of the product, be it food, cosmetics, or medical products, out of containers,” Varanasi says. “Fifty billion-plus packages are sold every year, and 5 to 10 percent of product is left behind on average. So, you can imagine the CO₂ footprint of the wasted product. And even though a lot of this is in recyclable packaging, they can’t be recycled because you need to wash out all the product. The water footprint of this is huge, not to mention the wasted product.”

While all of that was going on, Arnasi’s team was also looking into the biomedical space. For instance, Varanasi’s lab previously showed the technology could be used to prevent occlusion from blood clots and thrombosis and reduce biofilm formation, among other applications.

After studying the industry and speaking with patients and nurses, Arnasi realized a better lubricant for ostomy pouches could improve millions of people’s lives.

“Stool accumulates in these pouches outside of people’s bodies, and they need to empty it up to eight times a day,” explains Brienne Engel, Arnasi’s director of business development. “That process has a lot of challenges associated with it: It can be difficult to drain, leaving a lot of mass behind, it takes a long time to drain, so you can spend a long time in a restroom trying to clear out your pouch, and then there’s something called pancaking that can push the pouch off the [surgical opening], introducing issues like leakage, odor, and failure of the ostomy pouching system.”

Ostomy and beyond

Arnasi’s ostomy lubricant, Revel, is the first non-water-based solution on the market, and as-yet unpublished third-party testing has shown it allows for faster, more complete pouch drainage, along with other benefits.

“A lot of the existing brands treat their consumers like patients, but what we’ve found is they want to be treated like people and have a consumer experience,” Salain says. “The magic we saw with our toothpaste product was people got this amazing consumer experience out of it, and we wanted to create the same thing with Revel.”

Now Arnasi is planning to use its technology in medical products for skin infections, cystic fibrosis, and in implantable catheters and joint replacements. Arnasi’s team believes those last two use cases could prevent millions of deadly infections.

“When people are getting hemodialysis catheters, they have a 33 percent risk of developing infections, and those that do get those infections have a 25 percent chance of dying from them,” Engel says. “Taking our underlying technology and applying it to catheters, for example, imparts anti-biofilm properties and also prevent things like thrombosis, or blood clotting on the outside of these catheters, which is a problem in and of itself but also provides a space for bacteria to seed.”

Ultimately, Varanasi’s team is balancing making progress on its biomedical applications while exploring other avenues for its technology — including energy, manufacturing, and agriculture — to maximize its impact on the world.

“We think of this as a company with many companies within it because of all the different areas that it can impact. Liquid-solid interfaces are ubiquitous, viscous products are everywhere, and deploying this technology to solve difficult problems has been a dream,” Varanasi says. “It’s a great example of how MIT technology can be used for the benefit of humankind.”

After exposure in space aboard the International Space Station, a new kind of surface treatment significantly reduced the growth of biofilms, scientists report. Biofilms are mats of microbial or fungal growth that can clog hoses or filters in water processing systems, or potentially cause illness in people.

In the experiment, researchers investigated a variety of surfaces treated in different ways and exposed to a bacteria called Pseudomonas aeruginosa, which is an opportunistic pathogen than can cause infections in humans, especially in hospitals. The surfaces were incubated for three days aboard the space station, starting in 2019. The results show that textured surfaces impregnated with a lubricant were highly successful at preventing biofilm growth during their long exposure in space. The findings are described in a paper in the journal Nature Microgravity, by Samantha McBride PhD ’20 and Kripa Varanasi of MIT, Pamela Flores and Luis Zea at the University of Colorado, and Jonathan Galakza at NASA Ames Research Center.

Clogs in water recovery system hoses aboard the ISS have been so severe at times, the hoses had to be sent back to Earth for cleaning and refurbishing. And while it isn’t known whether biofilms have directly contributed to astronaut illnesses, on Earth, biofilms are associated with 65 percent of microbial infections, and 80 percent of chronic infections, the researchers say.

One approach to preventing biofilms is to use surfaces coated with certain metals or oxides that kill microbes, but this approach can fail when a layer of dead microbes builds up on the surface and allows biofilm to form above it. But this was not the case with the liquid-infused surface that performed well in the ISS experiments: Rather than killing the microbes, it prevented them from adhering to the surface in the first place.

The specific surface used was made of silicon that was etched to produce a nanoscale forest of pillars. This spiky surface is then infused with a silicon oil, which is drawn into the texture and held in place by capillary action, leaving a smooth and highly slippery surface that significantly reduces the adhesion of microbes and prevents them from forming a biofilm.

Identical experiments were conducted on Earth as well as on the space station to determine the differences produced by the microgravity environment in orbit. To the researchers' surprise, the liquid-infused surface performed even better in space than it did on Earth at preventing microbial adhesion.

On previous and current space stations, including the USSR’s Mir station, Salyut 6, and Salyut 7,  as well as the International Space Station, “they’ve seen these biofilms, and they jeopardize a variety of instruments or equipment, including space suits, recycling units, radiators, and water treatment facilities, so it’s a very important problem that needed to be understood,” says Varanasi, a professor of mechanical engineering and founder of a company called LiquiGlide, which makes liquid-impregnated surfaces for containers to help their contents slide out.

Previous tests on Earth had shown that these treated surfaces could significantly reduce biofilm adhesion. When the samples from the space station were retrieved and tested, “we found that these surfaces are extremely good at preventing biofilm formation in the space station as well,” Varanasi says. This is important because past work has found that microgravity can have a significant influence on biofilm morphologies, attachment behavior, and gene expression, according to McBride. Thus, strategies that work well on Earth for biofilm mitigation may not necessarily be applicable to microgravity situations.

Preventing biofilms will be especially important for future long-duration missions, such as to the moon or Mars, where the option of quickly returning fouled equipment or sick astronauts to Earth will not be available, the team says. If further testing confirms its long-term stability and successful biofilm prevention, coatings based on the liquid-treated surface concept could be applied to a variety of critical components that are known to be susceptible to biofilm fouling, such as water treatment hoses and filters, or to parts that come in close contact with astronauts, such as gloves or food preparation surfaces.

In the terrestrial samples, biofilm formation was reduced by about 74 percent, while the space station samples showed a reduction of about 86 percent, says Flores, who did much of the testing of the ISS-exposed samples. “The results we got were surprising,” she says, because earlier tests carried out by others had shown biofilm formation was actually greater in space than on Earth. “We actually found the opposite on these samples,” she says.

While the tests used a specific and well-studied gram-negative kind of bacteria, she says, the results should apply to any kind of gram-negative bacteria, and likely to gram-positive bacteria as well. They found that the areas of the surface where no bacterial growth took place were covered by a thin layer of nucleic acids, which have a slight negative electric charge that may have helped to prevent microbes from adhering. Both gram-positive and gram-negative bacteria have a slight negative charge, which could repel them from that negatively charged surface, Flores says.

Other types of anti-fouling surfaces, Varanasi says, “work mostly on a biocidal property, which usually only works for a first layer of cells because after those cells die they can form a deposit, and microbes can grow on top of them. So, usually it’s been a very hard problem.” But with the liquid-impregnated surface, where what is exposed is mostly just the liquid itself, there are very few defects or points where the bacteria can find a footing, he says.

Although the test material was on the space station for more than a year, the actual tests were only performed over a three-day period because they required active participation by the astronauts whose schedules are always very busy. But one recommendation the team has made, based on these initial results, is that longer-duration tests should be carried out on a future mission. In these first tests, Flores says, the results after the third day looked the same as after the first and second days. “We don’t know for how long it will be able to keep up this performance, so we definitely recommend a longer time of incubation, and also, if possible, a continuous analysis, and not just end points.”

Zea, who initiated the project with NASA, says that this was the first time the agency has conducted tests that involved joint participation by two of its science programs, biology and physical sciences. “I think it stresses the importance of multidisciplinarity because we need to be able to combine these different disciplines to find solutions to real world problems.”

Biofilms are also a significant medical issue on Earth, especially on medical devices or implants including catheters, where they can lead to significant disease problems. The same kind of liquid-impregnated surfaces may have a role to play in helping to address these issues, Varanasi says.

The project was supported by NASA and used facilities provided by several other companies and organizations.

After exposure in space aboard the International Space Station, a new kind of surface treatment significantly reduced the growth of biofilms, scientists report. Biofilms are mats of microbial or fungal growth that can clog hoses or filters in water processing systems, or potentially cause illness in people.

In the experiment, researchers investigated a variety of surfaces treated in different ways and exposed to a bacteria called Pseudomonas aeruginosa, which is an opportunistic pathogen than can cause infections in humans, especially in hospitals. The surfaces were incubated for three days aboard the space station, starting in 2019. The results show that textured surfaces impregnated with a lubricant were highly successful at preventing biofilm growth during their long exposure in space. The findings are described in a paper in the journal Nature Microgravity, by Samantha McBride PhD ’20 and Kripa Varanasi of MIT, Pamela Flores and Luis Zea at the University of Colorado, and Jonathan Galakza at NASA Ames Research Center.

Clogs in water recovery system hoses aboard the ISS have been so severe at times, the hoses had to be sent back to Earth for cleaning and refurbishing. And while it isn’t known whether biofilms have directly contributed to astronaut illnesses, on Earth, biofilms are associated with 65 percent of microbial infections, and 80 percent of chronic infections, the researchers say.

One approach to preventing biofilms is to use surfaces coated with certain metals or oxides that kill microbes, but this approach can fail when a layer of dead microbes builds up on the surface and allows biofilm to form above it. But this was not the case with the liquid-infused surface that performed well in the ISS experiments: Rather than killing the microbes, it prevented them from adhering to the surface in the first place.

The specific surface used was made of silicon that was etched to produce a nanoscale forest of pillars. This spiky surface is then infused with a silicon oil, which is drawn into the texture and held in place by capillary action, leaving a smooth and highly slippery surface that significantly reduces the adhesion of microbes and prevents them from forming a biofilm.

Identical experiments were conducted on Earth as well as on the space station to determine the differences produced by the microgravity environment in orbit. To the researchers' surprise, the liquid-infused surface performed even better in space than it did on Earth at preventing microbial adhesion.

On previous and current space stations, including the USSR’s Mir station, Salyut 6, and Salyut 7,  as well as the International Space Station, “they’ve seen these biofilms, and they jeopardize a variety of instruments or equipment, including space suits, recycling units, radiators, and water treatment facilities, so it’s a very important problem that needed to be understood,” says Varanasi, a professor of mechanical engineering and founder of a company called LiquiGlide, which makes liquid-impregnated surfaces for containers to help their contents slide out.

Previous tests on Earth had shown that these treated surfaces could significantly reduce biofilm adhesion. When the samples from the space station were retrieved and tested, “we found that these surfaces are extremely good at preventing biofilm formation in the space station as well,” Varanasi says. This is important because past work has found that microgravity can have a significant influence on biofilm morphologies, attachment behavior, and gene expression, according to McBride. Thus, strategies that work well on Earth for biofilm mitigation may not necessarily be applicable to microgravity situations.

Preventing biofilms will be especially important for future long-duration missions, such as to the moon or Mars, where the option of quickly returning fouled equipment or sick astronauts to Earth will not be available, the team says. If further testing confirms its long-term stability and successful biofilm prevention, coatings based on the liquid-treated surface concept could be applied to a variety of critical components that are known to be susceptible to biofilm fouling, such as water treatment hoses and filters, or to parts that come in close contact with astronauts, such as gloves or food preparation surfaces.

In the terrestrial samples, biofilm formation was reduced by about 74 percent, while the space station samples showed a reduction of about 86 percent, says Flores, who did much of the testing of the ISS-exposed samples. “The results we got were surprising,” she says, because earlier tests carried out by others had shown biofilm formation was actually greater in space than on Earth. “We actually found the opposite on these samples,” she says.

While the tests used a specific and well-studied gram-negative kind of bacteria, she says, the results should apply to any kind of gram-negative bacteria, and likely to gram-positive bacteria as well. They found that the areas of the surface where no bacterial growth took place were covered by a thin layer of nucleic acids, which have a slight negative electric charge that may have helped to prevent microbes from adhering. Both gram-positive and gram-negative bacteria have a slight negative charge, which could repel them from that negatively charged surface, Flores says.

Other types of anti-fouling surfaces, Varanasi says, “work mostly on a biocidal property, which usually only works for a first layer of cells because after those cells die they can form a deposit, and microbes can grow on top of them. So, usually it’s been a very hard problem.” But with the liquid-impregnated surface, where what is exposed is mostly just the liquid itself, there are very few defects or points where the bacteria can find a footing, he says.

Although the test material was on the space station for more than a year, the actual tests were only performed over a three-day period because they required active participation by the astronauts whose schedules are always very busy. But one recommendation the team has made, based on these initial results, is that longer-duration tests should be carried out on a future mission. In these first tests, Flores says, the results after the third day looked the same as after the first and second days. “We don’t know for how long it will be able to keep up this performance, so we definitely recommend a longer time of incubation, and also, if possible, a continuous analysis, and not just end points.”

Zea, who initiated the project with NASA, says that this was the first time the agency has conducted tests that involved joint participation by two of its science programs, biology and physical sciences. “I think it stresses the importance of multidisciplinarity because we need to be able to combine these different disciplines to find solutions to real world problems.”

Biofilms are also a significant medical issue on Earth, especially on medical devices or implants including catheters, where they can lead to significant disease problems. The same kind of liquid-impregnated surfaces may have a role to play in helping to address these issues, Varanasi says.

The project was supported by NASA and used facilities provided by several other companies and organizations.

After exposure in space aboard the International Space Station, a new kind of surface treatment significantly reduced the growth of biofilms, scientists report. Biofilms are mats of microbial or fungal growth that can clog hoses or filters in water processing systems, or potentially cause illness in people.

In the experiment, researchers investigated a variety of surfaces treated in different ways and exposed to a bacteria called Pseudomonas aeruginosa, which is an opportunistic pathogen than can cause infections in humans, especially in hospitals. The surfaces were incubated for three days aboard the space station, starting in 2019. The results show that textured surfaces impregnated with a lubricant were highly successful at preventing biofilm growth during their long exposure in space. The findings are described in a paper in the journal Nature Microgravity, by Samantha McBride PhD ’20 and Kripa Varanasi of MIT, Pamela Flores and Luis Zea at the University of Colorado, and Jonathan Galakza at NASA Ames Research Center.

Clogs in water recovery system hoses aboard the ISS have been so severe at times, the hoses had to be sent back to Earth for cleaning and refurbishing. And while it isn’t known whether biofilms have directly contributed to astronaut illnesses, on Earth, biofilms are associated with 65 percent of microbial infections, and 80 percent of chronic infections, the researchers say.

One approach to preventing biofilms is to use surfaces coated with certain metals or oxides that kill microbes, but this approach can fail when a layer of dead microbes builds up on the surface and allows biofilm to form above it. But this was not the case with the liquid-infused surface that performed well in the ISS experiments: Rather than killing the microbes, it prevented them from adhering to the surface in the first place.

The specific surface used was made of silicon that was etched to produce a nanoscale forest of pillars. This spiky surface is then infused with a silicon oil, which is drawn into the texture and held in place by capillary action, leaving a smooth and highly slippery surface that significantly reduces the adhesion of microbes and prevents them from forming a biofilm.

Identical experiments were conducted on Earth as well as on the space station to determine the differences produced by the microgravity environment in orbit. To the researchers' surprise, the liquid-infused surface performed even better in space than it did on Earth at preventing microbial adhesion.

On previous and current space stations, including the USSR’s Mir station, Salyut 6, and Salyut 7,  as well as the International Space Station, “they’ve seen these biofilms, and they jeopardize a variety of instruments or equipment, including space suits, recycling units, radiators, and water treatment facilities, so it’s a very important problem that needed to be understood,” says Varanasi, a professor of mechanical engineering and founder of a company called LiquiGlide, which makes liquid-impregnated surfaces for containers to help their contents slide out.

Previous tests on Earth had shown that these treated surfaces could significantly reduce biofilm adhesion. When the samples from the space station were retrieved and tested, “we found that these surfaces are extremely good at preventing biofilm formation in the space station as well,” Varanasi says. This is important because past work has found that microgravity can have a significant influence on biofilm morphologies, attachment behavior, and gene expression, according to McBride. Thus, strategies that work well on Earth for biofilm mitigation may not necessarily be applicable to microgravity situations.

Preventing biofilms will be especially important for future long-duration missions, such as to the moon or Mars, where the option of quickly returning fouled equipment or sick astronauts to Earth will not be available, the team says. If further testing confirms its long-term stability and successful biofilm prevention, coatings based on the liquid-treated surface concept could be applied to a variety of critical components that are known to be susceptible to biofilm fouling, such as water treatment hoses and filters, or to parts that come in close contact with astronauts, such as gloves or food preparation surfaces.

In the terrestrial samples, biofilm formation was reduced by about 74 percent, while the space station samples showed a reduction of about 86 percent, says Flores, who did much of the testing of the ISS-exposed samples. “The results we got were surprising,” she says, because earlier tests carried out by others had shown biofilm formation was actually greater in space than on Earth. “We actually found the opposite on these samples,” she says.

While the tests used a specific and well-studied gram-negative kind of bacteria, she says, the results should apply to any kind of gram-negative bacteria, and likely to gram-positive bacteria as well. They found that the areas of the surface where no bacterial growth took place were covered by a thin layer of nucleic acids, which have a slight negative electric charge that may have helped to prevent microbes from adhering. Both gram-positive and gram-negative bacteria have a slight negative charge, which could repel them from that negatively charged surface, Flores says.

Other types of anti-fouling surfaces, Varanasi says, “work mostly on a biocidal property, which usually only works for a first layer of cells because after those cells die they can form a deposit, and microbes can grow on top of them. So, usually it’s been a very hard problem.” But with the liquid-impregnated surface, where what is exposed is mostly just the liquid itself, there are very few defects or points where the bacteria can find a footing, he says.

Although the test material was on the space station for more than a year, the actual tests were only performed over a three-day period because they required active participation by the astronauts whose schedules are always very busy. But one recommendation the team has made, based on these initial results, is that longer-duration tests should be carried out on a future mission. In these first tests, Flores says, the results after the third day looked the same as after the first and second days. “We don’t know for how long it will be able to keep up this performance, so we definitely recommend a longer time of incubation, and also, if possible, a continuous analysis, and not just end points.”

Zea, who initiated the project with NASA, says that this was the first time the agency has conducted tests that involved joint participation by two of its science programs, biology and physical sciences. “I think it stresses the importance of multidisciplinarity because we need to be able to combine these different disciplines to find solutions to real world problems.”

Biofilms are also a significant medical issue on Earth, especially on medical devices or implants including catheters, where they can lead to significant disease problems. The same kind of liquid-impregnated surfaces may have a role to play in helping to address these issues, Varanasi says.

The project was supported by NASA and used facilities provided by several other companies and organizations.

After exposure in space aboard the International Space Station, a new kind of surface treatment significantly reduced the growth of biofilms, scientists report. Biofilms are mats of microbial or fungal growth that can clog hoses or filters in water processing systems, or potentially cause illness in people.

In the experiment, researchers investigated a variety of surfaces treated in different ways and exposed to a bacteria called Pseudomonas aeruginosa, which is an opportunistic pathogen than can cause infections in humans, especially in hospitals. The surfaces were incubated for three days aboard the space station, starting in 2019. The results show that textured surfaces impregnated with a lubricant were highly successful at preventing biofilm growth during their long exposure in space. The findings are described in a paper in the journal Nature Microgravity, by Samantha McBride PhD ’20 and Kripa Varanasi of MIT, Pamela Flores and Luis Zea at the University of Colorado, and Jonathan Galakza at NASA Ames Research Center.

Clogs in water recovery system hoses aboard the ISS have been so severe at times, the hoses had to be sent back to Earth for cleaning and refurbishing. And while it isn’t known whether biofilms have directly contributed to astronaut illnesses, on Earth, biofilms are associated with 65 percent of microbial infections, and 80 percent of chronic infections, the researchers say.

One approach to preventing biofilms is to use surfaces coated with certain metals or oxides that kill microbes, but this approach can fail when a layer of dead microbes builds up on the surface and allows biofilm to form above it. But this was not the case with the liquid-infused surface that performed well in the ISS experiments: Rather than killing the microbes, it prevented them from adhering to the surface in the first place.

The specific surface used was made of silicon that was etched to produce a nanoscale forest of pillars. This spiky surface is then infused with a silicon oil, which is drawn into the texture and held in place by capillary action, leaving a smooth and highly slippery surface that significantly reduces the adhesion of microbes and prevents them from forming a biofilm.

Identical experiments were conducted on Earth as well as on the space station to determine the differences produced by the microgravity environment in orbit. To the researchers' surprise, the liquid-infused surface performed even better in space than it did on Earth at preventing microbial adhesion.

On previous and current space stations, including the USSR’s Mir station, Salyut 6, and Salyut 7,  as well as the International Space Station, “they’ve seen these biofilms, and they jeopardize a variety of instruments or equipment, including space suits, recycling units, radiators, and water treatment facilities, so it’s a very important problem that needed to be understood,” says Varanasi, a professor of mechanical engineering and founder of a company called LiquiGlide, which makes liquid-impregnated surfaces for containers to help their contents slide out.

Previous tests on Earth had shown that these treated surfaces could significantly reduce biofilm adhesion. When the samples from the space station were retrieved and tested, “we found that these surfaces are extremely good at preventing biofilm formation in the space station as well,” Varanasi says. This is important because past work has found that microgravity can have a significant influence on biofilm morphologies, attachment behavior, and gene expression, according to McBride. Thus, strategies that work well on Earth for biofilm mitigation may not necessarily be applicable to microgravity situations.

Preventing biofilms will be especially important for future long-duration missions, such as to the moon or Mars, where the option of quickly returning fouled equipment or sick astronauts to Earth will not be available, the team says. If further testing confirms its long-term stability and successful biofilm prevention, coatings based on the liquid-treated surface concept could be applied to a variety of critical components that are known to be susceptible to biofilm fouling, such as water treatment hoses and filters, or to parts that come in close contact with astronauts, such as gloves or food preparation surfaces.

In the terrestrial samples, biofilm formation was reduced by about 74 percent, while the space station samples showed a reduction of about 86 percent, says Flores, who did much of the testing of the ISS-exposed samples. “The results we got were surprising,” she says, because earlier tests carried out by others had shown biofilm formation was actually greater in space than on Earth. “We actually found the opposite on these samples,” she says.

While the tests used a specific and well-studied gram-negative kind of bacteria, she says, the results should apply to any kind of gram-negative bacteria, and likely to gram-positive bacteria as well. They found that the areas of the surface where no bacterial growth took place were covered by a thin layer of nucleic acids, which have a slight negative electric charge that may have helped to prevent microbes from adhering. Both gram-positive and gram-negative bacteria have a slight negative charge, which could repel them from that negatively charged surface, Flores says.

Other types of anti-fouling surfaces, Varanasi says, “work mostly on a biocidal property, which usually only works for a first layer of cells because after those cells die they can form a deposit, and microbes can grow on top of them. So, usually it’s been a very hard problem.” But with the liquid-impregnated surface, where what is exposed is mostly just the liquid itself, there are very few defects or points where the bacteria can find a footing, he says.

Although the test material was on the space station for more than a year, the actual tests were only performed over a three-day period because they required active participation by the astronauts whose schedules are always very busy. But one recommendation the team has made, based on these initial results, is that longer-duration tests should be carried out on a future mission. In these first tests, Flores says, the results after the third day looked the same as after the first and second days. “We don’t know for how long it will be able to keep up this performance, so we definitely recommend a longer time of incubation, and also, if possible, a continuous analysis, and not just end points.”

Zea, who initiated the project with NASA, says that this was the first time the agency has conducted tests that involved joint participation by two of its science programs, biology and physical sciences. “I think it stresses the importance of multidisciplinarity because we need to be able to combine these different disciplines to find solutions to real world problems.”

Biofilms are also a significant medical issue on Earth, especially on medical devices or implants including catheters, where they can lead to significant disease problems. The same kind of liquid-impregnated surfaces may have a role to play in helping to address these issues, Varanasi says.

The project was supported by NASA and used facilities provided by several other companies and organizations.