Category Archives: environment

Enhance sunscreen without harming the environment by using octopus and squid pigments

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These days it seems experts are encouraging people wear sunscreen all year round. Anyway, that’s my excuse for claiming that this is a timely announcement, from a July 22, 2024 news item on phys.org,

When Northeastern [Northeastern University; Boston, Massachusetts] graduate Camille Martin and associate professor Leila Deravi co-founded Seaspire, a skincare ingredients company inspired by pigment in octopus and squid, their goal was to create a product that is good for your skin and the environment.

New research shows that they are on the right track.

…

A July 19, 2024 Northeastern University news release by Cynthia McCormick Hibbert, which originated the news item, reveals more about the research, Note: Links have been removed,

A paper published in the International Journal of Cosmetic Science says that Xanthochrome, a synthesized version of a molecule found in cephalopods such as squid, octopus and cuttlefish, boosts levels of sunscreen protection in combination with zinc oxide while having no adverse effects on coral cuttings.

The marine safety findings are important because “there’s a lot of toxicities involved with (traditional) UV filters in sunscreens,” says Deravi, who is Seaspire’s scientific adviser and an associate professor of chemistry and chemical biology.

“Some of the chemical UV-filters in particular are known to create reactive oxygen species that are not only bad for the environment but can also seep into our skin and cause systemic toxicities,” she says.

The result is a pressing need for environmentally friendly ingredients, says Martin, who got her Ph.D. in chemistry from Northeastern in 2019 and has served as Seaspire’s CEO since its founding that year.

“The industry is really excited about new materials innovations,” she says. “Everything we do as a biotechnology company is centered around leveraging marine animals as a source of inspiration for the next generation of skin care ingredients.”

From lab to market

The goal of Seaspire, Martin says, is to make Xanthochrome available to skin care product manufacturers and distributors up and down the supply chain so that it ends up in a wide range of ski care and personal care products including sunscreens, anti-aging applications and functional color cosmetics.

“We are just wrapping up the research and development on it now and actively looking for partnerships to bring this to market,” Deravi says.

Produced as a brown, textured powder, Xanthochrome has potent antioxidant and skin restorative properties as well as having light scattering qualities that provide protection against photoaging, Martin and Deravi say.

Martin says Xanthochrome is the trade name for a chemically synthesized version of xanthommatin, which is found in the skin of cuttlefish, octopus and squid and in insects as well.

“The secret to the cephalopods’ unique coloration is derived from its multifunctional chemical compounds, which we identified in our lab at Northeastern,” Deravi says.

“Camille’s Ph.D. work was the first to show that these small molecules inside cephalopod skin that contribute to camouflage in the animal also have really interesting antioxidant properties,” Deravi says.

“They’re free radical scavengers, which are very important for skin health and skin barrier function,” she says.

“And then they also have pretty important optical properties protecting against exposure to sunlight, which is the main function of some UV filters and sunscreens,” Deravi says.

“We didn’t create a new molecule,” Martin says. “We were able to isolate and characterize the properties of the biomolecules found within cephalopods, engineer a bio-identical version of the naturally occurring material and position Xanthochrome as a new active ingredient that provides a wide range of skin care benefits.”

“It’s a really interesting space where you have a single molecule that can have so many functions,” she says.

Previous research showed Xanthochrome, unlike the parabens that often go into sunscreens, is not an endocrine disruptor.

The most recent study shows that it boosts the ultraviolet protection of zinc oxide, which the U.S. Food and Drug Administration considers a safe and effective ingredient in sunscreen, by 28% and the blocking potential of visible light by 45%.

It also showed Xanthochrome did not have an adverse effect on coral cuttings even at concentrations five times higher than what are used in typical formulations.

Martin and Deravi hope that skincare product manufacturers see Xanthochrome as a next-generation ingredient on the heels of retinoids and vitamin C and hyaluronic acid.

“We’re creating products that can really be applied and adopted across a wide range of users,” Martin says. “We are creating something that is not only safe for all people, but also the environment.”

“You have to prove the new raw materials are safe for humans and also for the ocean, where ultimately every product is going to get washed into,” Deravi says.

Here’s a link to and a citation for the paper,

Using cephalopod-inspired chemistry to extend long-wavelength ultraviolet and visible light protection of mineral sunscreens by Leila F. Deravi, Isabel Cui, Camille A. Martin. International Journal of Cosmetic Science (2024) DOI: https://doi.org/10.1111/ics.12993 First published: 19 July 2024

This paper is behind a paywall.

The Seaspire Skincare website does not have any information about where you might access products with Xanthochrome. I’ll be keeping watch hoping to see some products in the not too distant future.

Fashion, sustainability, and the protein threads that bind textiles and cosmetics

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I’m starting with a somewhat enthusiastic overview of the role synthetic biology is playing in the world of clothing and cosmetics in The Scientist and following it up with some stories about fish leather, no synthetic biology involved but all of these stories are about sustainability and fashion and, in one case, cosmetics.

Fashionable synthetic biology

Meenakshi Prabhune’s June 14, 2024 article in The Scientist, in addition to the overview, provides information that explains how some of the work on textiles and leather is being used in the production of cosmetics. She starts with a little history/mythology and then launches into the synthetic biology efforts to produce silk and leather suitable for consumer use, Note: Links have been removed,

Once upon a time, circa 2700 BC in China, empress Xi Ling Shi was enjoying her afternoon tea under a mulberry tree, when a silkworm cocoon fell from the tree into her tea. She noticed that on contact with the hot beverage, the cocoon unraveled into a long silky thread. This happy accident inspired her to acquire these threads in abundance and fashion them into an elegant fabric. 

So goes the legend, according to the writings of Confucius, about the discovery of silk and the development of sericulture in ancient China. Although archaeological evidence from Chinese ruins dates the presence of silk to 8500 years ago, hinting that the royal discovery story was spun just like the silk fabric, one part of the legend rings true.1 The Chinese royals played a pivotal role in popularizing silk as a symbol of status and wealth. By 130 BC, emperors in the Ancient Civilizations across the world desired to be clad in silken garments, paving the Silk Road that opened trade routes from China to the West. 

While silk maintained its high-society status over the next thousands of years, the demand for easy-to-use materials grew among mass consumers. In the early 20th century, textile developers applied their new-found technological prowess to make synthetic materials: petrochemical-based polymer blended textiles with improved durability, strength, and convenience. 

…

In their quest to make silk powerful again, not by status but rather by thread strength, scientists turned to an arachnoid. Dragline silk, the thread by which the spider hangs itself from the web, is one of the strongest fibers; its tensile strength—a measure of how much a polymer deforms when strained—is almost thrice that of silkworm silk.2 

Beyond durable fashion garments, tough silk fibers are coveted in parachutes, military protective gear, and automobile safety belts, among other applications, so scientists are keen to pull on these threads. While traditional silk production relies on sericulture, arachnophobes can relax: spider farms are not a thing.

“Spiders make very little silk and are quite territorial. So, the only way to do it is to make microbes that make the protein,” said David Breslauer, cofounder and chief technology officer at Bolt Threads, a bio apparel company. 

For decades, researchers have coaxed microbes into churning their metabolites in large fermentation tanks, which they have harvested to solve dire crises in many areas. For instance, when pharmaceuticals struggled to meet the growing demand for insulin through the traditional methods of extraction from animal pancreas, researchers at Genentech sought the aid of E. coli to generate recombinant insulin for mass production in 1978.3  [emphases mine]

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Prabhune’s June 14, 2024 article notes some difficulties with spider silk, Note: Links have been removed,

… researchers soon realized that producing spider silk in microbes was no easy feat. The spider silk protein, spidroin, is larger than 300 kDa in size—a huge jump from the small 6 kDa recombinant insulin. Bulky proteins impose a heavy metabolic load on the microbes and their production yield tanks. Also, spidroin consists of repeating regions of glycine and alanine amino acids that impart strength and elasticity to the material, but the host microbes struggle with protein folding and overexpression of the corresponding tRNA molecules.4  

…

… researchers had gotten close, but they hadn’t been able to synthesize the full spidroin protein. Since the molecular weight of the silk protein correlates with the strength of the silk thread, Zhang [Fuzhong Zhang, a synthetic biologist at Washington University in St. Louis] was determined to produce the entire protein to mimic the silk’s natural properties.5

To achieve this goal without pushing the metabolic limits of the bacteria, Zhang and his team literally broke down the problem. In 2018, they devised a recombinant spidroin by constructing two protein halves with split inteins—peptides known to catalyze ligation between proteins while splicing out their own residues—tagged at their ends. They synthesized the halves in separate E. coli cultures, mixed the two cultures, and ligated the proteins to yielded a recombinant spidroin of 556 kDa—a size that was previously considered unobtainable.6 The resulting silk fiber made from these recombinant spidroins matched the mechanical properties of natural spider silk fiber.

…

While synthesizing the high molecular weight protein validated their technical prowess and strategy, Zhang knew that the yield with this approach was going to be unavoidably low. “It was not even enough to make a simple shirt,” he said.

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Zhang and his team did solve the problem of getting a higher yield but that led to another problem, from Prabhune’s June 14, 2024 article,

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Breslauer echoed the importance of this step. He recalled how scaling up was the biggest challenge when he and his cofounder Dan Widmaier, chief executive officer at Bolt Threads, first set up shop in 2009. The duo met during their graduate studies. Breslauer, a material science student at the University of California, Berkeley, was fascinated by spider silk and sought help for synthesizing the protein in microbes. Luckily, he met Widmaier, a synthetic biology graduate student who was optimizing systems to study complex proteins.

When their collaboration to produce recombinant spider silk proteins in yeast yielded promising results, the duo decided to challenge the status quo in the textile industry by commercially producing bio-silk apparel, and Bolt Threads was born. The market transition, however, was not as smooth as the threads they produced. 

“There was so little innovation in the textile space, and brands were really eager to talk about innovation. It felt like there was demand there. Turns out, the desire for storytelling outweighed the desire for actual innovation with those brands,” Breslauer said. “We didn’t realize how adverse [sic] people were going to be to the idea because it was so unfamiliar.”

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Prabhune’s June 14, 2024 article also covers leather and cosmetics, Note: Links have been removed,

David Williamson, a chemist and the chief operations officer at Modern Meadow and his team wanted to separate themselves from the herd. In their quest for sustainable alternatives, they went back to the basic biology and chemistry of the material. As leather is made from animal skin, it is rich in collagen, a structural protein abundant in the extracellular matrix of connective tissues. If the team could produce this primary component protein at scale, they would be able to process it into leather downstream. 

In about 2017, Williamson and his team developed a fermentation-based approach to produce collagen from yeast. While they achieved scalable production, there was one small hiccup. The protein properties of collagen alone did not yield the mechanical properties they needed for their leather-like material. 

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The team went to the drawing board and analyzed the amino acid residues that contributed to collagen’s characteristics to look for a substitute protein. They found an alternative that had the desirable functional elements of collagen but was also sustainable and cost effective for industrial scale up: soy protein isolate. While tinkering with their recipes, they found the perfect combination for material strength by mixing in a bio-based polyurethane polymer with the protein to yield a refined bioalloy called Bio-VERA. 

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As natural textiles are derived from animal skin, hair, or proteins, it is no surprise that many synthetic biologists in the textile space have also found a niche in cosmetics. Even as the Modern Meadow team transitioned away from their protein fermentation strategies to innovate Bio-VERA, they realized that they could still apply their expertise in skincare. While leathery is not an adjective one desires to associate with skin, collagen is an integral component in both. “When our bodies make collagen and build our extracellular matrices, one of the first proteins that they deposit is type three collagen. So, you can think of type three collagen almost like the structure or scaffold of a building,” explained Williamson.

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To cater to the increasing demand for solutions to achieve younger looking skin, Williamson and his team engineered a recombinant collagen type three protein containing part of the protein sequence that is rich in binding domains for fibroblast interactions.9,10  “After you expose the extracellular matrix to this protein, it stimulates the fibroblasts to make more type three collagen. That type three collagen lays down type one collagen and elastin and fibronectin in a way that actually helps to turn back time, so to speak, to increase the ratio of type three collagen relative to type one collagen,” Williamson said. 

The Modern Meadow team are not the only ones to weave their textile strands into cosmetic applications. When Artur Cavaco-Paulo, a biological engineer at the University of Minho [Portugal], was studying wool fibers, he was struck by their structural similarities to human hair. “We decided that it would be a really good idea to transfer some of the knowledge that we had in wool textiles to human hair,” said Cavaco-Paulo. Particularly, he was interested in investigating solutions to fix hair strands damaged by highly alkaline chemical products. 

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Over the next few years, Cavaco-Paulo developed […] shortlisted peptides into the K18 peptide product, which is now part of a commercially available leave-in conditioner. Cavaco-Paulo serves as the chief scientific officer at the biotech company K18. 

Although he started his career with textile research, Cavaco-Paulo favors the cosmetics sector with regards to returns on research and technology investment. “The personal care market is much more accustomed to innovation and has a much better and more fluid pipeline on innovation,” seconded Breslauer. “Whereas, [in] apparel, you really have to twist arms to get people to work with your material.” Bolt Threads ventured into the personal care space when Breslauer and his team serendipitously stumbled upon an alternative use for one of their textile proteins. 

…

While it’s not mentioned in Prabhune’s June 14, 2024 article, sustainability is mentioned on two of the company websites,

Bolt Threads

Bolt Threads is a material solutions company. With nature as our inspiration, we invent cutting-edge materials for the fashion and beauty industries to put us on a path toward a more sustainable future.

Through innovative collaborations with world-class brands and supply chain partners, we are on a mission to create way better materials for a way better world. Join us.

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Modern Meadow

Modern Meadow is a climate-tech pioneer creating the future of materials through innovations in biology and material science.

​Our bio-materials technology platform with nature-inspired protein solutions delivers better performance, sustainability, scalability, and cost while reducing reliance on petrochemical and animal-based inputs.​

…

K18 has not adopted a ‘sustainability’ approach to marketing its hair care products.

Sustainability without synthetic biology: fish leather

In a January 3, 2022 posting I featured fish leather/skin in a story about the “Futures exhibition/festival” held at the Smithsonian Institute from November 20, 2021 to July 6, 2022.

Before getting to Futures, here’s a brief excerpt from a June 11, 2021 Smithsonian Magazine exhibition preview article by Gia Yetikyel about one of the contributors, Elisa Palomino-Perez (Note: A link has been removed),

Elisa Palomino-Perez sheepishly admits to believing she was a mermaid as a child. Growing up in Cuenca, Spain in the 1970s and ‘80s, she practiced synchronized swimming and was deeply fascinated with fish. Now, the designer’s love for shiny fish scales and majestic oceans has evolved into an empowering mission, to challenge today’s fashion industry to be more sustainable, by using fish skin as a material.

Luxury fashion is no stranger to the artist, who has worked with designers like Christian Dior, John Galliano and Moschino in her 30-year career. For five seasons in the early 2000s, Palomino-Perez had her own fashion brand, inspired by Asian culture and full of color and embroidery. It was while heading a studio for Galliano in 2002 that she first encountered fish leather: a material made when the skin of tuna, cod, carp, catfish, salmon, sturgeon, tilapia or pirarucu gets stretched, dried and tanned.

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The history of using fish leather in fashion is a bit murky. The material does not preserve well in the archeological record, and it’s been often overlooked as a “poor person’s” material due to the abundance of fish as a resource. But Indigenous groups living on coasts and rivers from Alaska to Scandinavia to Asia have used fish leather for centuries. Icelandic fishing traditions can even be traced back to the ninth century. While assimilation policies, like banning native fishing rights, forced Indigenous groups to change their lifestyle, the use of fish skin is seeing a resurgence. Its rise in popularity in the world of sustainable fashion has led to an overdue reclamation of tradition for Indigenous peoples.

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Brendan Jones provides an update of sorts in his Alaska-forward take in his February 22, 2024 article “Fish Leather Is Incredibly Strong and Beautiful. Can Makers ‘Scale Up’? Meet artisans in Alaska and BC who are sustaining, and advancing, an ancient art.” for The Tyee,

Fish leather artist June Pardue began her journey into the craft not knowing where to start. Which was a problem, considering that she had been given the job of demonstrating for tourists how to tan fish skin at the Alaska Native Heritage Center in Anchorage. “I couldn’t find anyone to teach me,” Pardue said with a laugh.

“One day a guy from Mississippi noticed me fumbling around. He kindly waited until everyone had left. Then he said, ‘Do you want me to share my grandpappy’s recipe for tanning snake skins?’”

His cocktail of alcohol and glycerin allowed her to soften the skins — as tourists looked on — for future use in clothing and bags. This worked fine until she began to grow uncomfortable dumping toxins down the drain. Now she uses plant-based tannins like those found in willow branches after the season’s first snowmelt. She harvests the branches gingerly, allowing the trees to survive for the next generation of fish tanners.

Pardue, who teaches at the University of Alaska, was born on Kodiak Island, off the southern coast of the state, in Old Harbor village. Alutiiq and Iñupiaq, she was raised in Akhiok, population about 50, and Old Harbor.

Following her bumpy start at the heritage center, Pardue has since gone on to become one of Alaska’s and Canada’s most celebrated instructors and practitioners in the field of fish leather, lighting the way for others in Alaska and Canada.

Among the people Pardue has advised is CEO and founder of 7 Leagues tannery Tasha Nathanson, who is based in Vancouver. She met with Pardue to share her idea of creating a business built on making fish leather into boots and other items for a large customer base.

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Before making her move to open a business, Nathanson spent a year running the numbers, she said. In 2022, the global fish leather market was valued at US$36.22 million. As fish tanneries open their doors and fashion houses take notice, the number is expected to grow 16 per cent annually, topping $100 million by 2030.

“Salmon certainly don’t come to mind when you think of tanning, but people are catching on,” said Judith Lehmann, a Sitka-based expert in fish leather, who took Pardue’s class. (The Tyee reached Lehmann in Panama, where she was experimenting with skins of bonito and mahi mahi.)

Growing numbers of buyers are willing to pay for not only the beauty but also the remarkable durability fish leather can offer. California-based eco-fashion designer Hailey Harmon’s company Aitch Aitch sells the Amelia, a teal backpack made of panelled salmon leather, for $795.

One company in France has started to collect fish skins from restaurants — material that would otherwise end up in trash cans — to make luxury watch bands and accessories. Designers like Prada, Louis Vuitton and Christian Dior have incorporated fish leather into their lines. Even Nike introduced running shoes made of perch skin.

Whether they know it or not, today’s trendsetters are rooted in ancient history. “People have been working with fish skins for thousands of years,” Pardue said. “Ireland, Iceland, Norway, China, Japan — it’s an age-old practice.”

…

“On a molecular level, fibres in fish leather are cross-hatched, as opposed to cow leather, which is just parallel,” Nathanson explained. “So, pound for pound, this leather is stronger, which is great for shoes. And it’s more available, and eco-conscious. It’s a win across the board.”

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Jones’s February 22, 2024 article has some wonderful embedded pictures and Beth Timmins’s May 1, 2019 article for the BBC (British Broadcasting Corporation), while a little dated, offers more information about the international scene.

Synthetic biology is a scientific practice that I find disconcerting at times. That said, I’m glad to see more work on sustainable products however they are derived. On that note I have a couple of recent stories:

  • “Three century long development of a scientific idea: body armor made from silk” is the title of my July 11, 2024 posting
  • “Grown from bacteria: plastic-free vegan leather that dyes itself” is the title of my June 26, 2024 posting

Enjoy!

Nano-treatment could help save mangroves from deadly disease

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Seems to be my week for coastal erosion. First, there was my August 23, 2024 posting “Electricity (electrodeposition) could help fight coastal (beach) erosion” and today, August 30, 2024, I’m featuring news I got about a month ago (late July 2024) regarding a special formula to help save mangroves on the Florida coast and other coasts where they are found.

A July 26, 2024 news item on ScienceDaily features news from the University of Central Florida, Note: Links have been removed,

Mangroves and palm trees are hallmarks of the Sunshine State not just for their beauty but for their immense importance to Florida’s coastlines.

Mangroves are crucial because they naturally protect coastal shores from storm damage and serve as vital wildlife habitats around the world.

Scientists at the University of Central Florida are working to preserve mangroves in Florida and across the world from an increasingly prevalent disease-causing variety of fungi that lies dormant but becomes active when the tree is exposed to stressors such as temperature fluctuation, pests or other diseases.

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A July 26, 2024 University of Central Florida (UCF) news release by Eddy Duryea (also on EurekAlert), which originated the news item, describes the disease (which hasn’t yet been formally named) and gives some details about the proposed treatment, Note: Links have been removed,

The disease does not yet have an official name, but it is being referred to by scientists as “Mangrove CNP.” It is caused by a group of fungal pathogens, including Curvularia, Neopestalotiopsis, and Pestalotiopsis, that causes yellowing and spots, and gradually weaken the mangrove until it ultimately dies.

Melissa Deinys, a UCF undergraduate researcher, and Jorge Pereira, a UCF graduate research assistant, are working to help turn the tide by developing and testing a promising nutritional cocktail comprised of nanoparticles to strengthen mangroves and counter the pathogens. The work is through UCF professor Swadeshmukul Santra’s Materials Innovation for Sustainable Agriculture (MISA) center at UCF, which is a U.S. Department of Agriculture-National Institute of Food and Agricultural recognized Center of Excellence.

Mangrove CNP in Florida was first identified as causing mangrove die-offs by Deinys in 2019 in Miami through her work with Fairchild Tropical Botanic Garden. Later, the Marine Resources Council, a non-profit organization dedicated to the protection and restoration of Florida’s Indian River Lagoon, verified and cited her efforts.

Deinys and collaborators with the MRC and Fairchild Tropical Botanic Garden have determined that about 80% of the mangroves they had sampled have tested positive for at least one of the fungal pathogen species. She says they have sampled over 130 mangroves between the Indian River Lagoon and Miami mangrove populations.

The researchers are treating the mangroves by soaking them in a nutrient solution called “Mag Sun” (MgSuN), which is comprised of magnesium and sulfur nanoparticles. The mixture is a refinement of a previous graduate student’s formula that destroyed bacteria on tomatoes, Pereira says.

“The reason why we choose magnesium is because it is more environmentally friendly, and plants need a lot of magnesium,” he says. “I combined our magnesium formulation with a sodium polysulfide. Sulfur is one of those elements that is ubiquitous in the environment, and the idea is that you can combine both to actually enhance the anti-microbial capacity for both bacteria and fungi and you also supply key nutrients to the plants so that they can grow greener and leafier.”

During lab tests, the researchers say they observed growth inhibition of up to 95% when treated with MgSuN at varying concentrations compared to the untreated control.

The formula acts as a sort of antibiotic and multivitamin, and it has shown great potential in bolstering the health of infected mangroves at nurseries across Florida, Pereira says.

“We’ve done some experiments, and we have tested both in vitro and in plants,” he says. “We’re working with the nurseries, and we’ve seen it does kill the pathogens with no detrimental effects to the mangroves while kickstarting their health. They look great after treatment.”

Deinys is continuing her work with the Fairchild Tropical Botanic Garden, MRC and nurseries across Florida while staying the course on her path to graduation and furthering her research at UCF.

She began studying the fungal pathogens in 2018 in Miami prior to being enrolled at UCF and has seen the mangroves become increasingly affected by the pathogens’ opportunistic nature.

“Back at the botanical gardens where I started, I would see the plants have these pathogens but not to a detrimental effect where we now see these organisms collapsing,” she says. “A mangrove nursery [The Marine Resources Council] had reached out to us, and they told us they had an insect infestation and then the whole population got wiped out by the pathogen. We’re also getting reports from places like Tampa that say areas that have more runoff are having more pathogen-related deterioration compared to 10 years ago.”

The fungi have been well-documented for some time, but volatile temperature changes, frequent storms and other increasing stressors open the door to the fungi taking a hold of the mangroves, Deinys says.

“They’re called opportunistic, and they’re called that for a reason,” she says. “They see a change in the plant and that’s when they start to take effect.”

How the pathogens are acquired is something that remains unclear, Deinys says. Researchers hypothesize it may be introduced through water, wind or insects, but further studies are needed to determine how it is acquired since it poses threat to mangrove health.

“You have to study all possibilities to determine what is the vector,” Deinys says. “We’ve seen papers and literature in other countries that have shown these pathogens for a long time. It’s been difficult because there is a disconnect in mangrove communities because we’re worlds apart and with different languages.”

The MgSuN nutrient solution is a treatment, but not a cure, Deinys says. There still are ample stressors that should be managed and mitigated, such as human-caused habitat destruction, in addition to treating the pathogens.

“I think there’s a big restoration effort to repopulate mangroves,” she says. “But first we need to look at the health of these mangroves and the health of the ecosystem before we determine what more we should do. We’re working with mangrove nurseries to see if we can together develop solutions.”

Maintaining and restoring mangroves is an essential component of ecological stewardship, and it’s a passion that Deinys hopes to continue throughout her career.

“I started this project my freshman year,” she says. “I didn’t want to leave what I was doing, and I came here with a mission. I met with Dr. Santra, our PI, and he wanted to help. He gave me a lot of freedom, and I’m really grateful.”

Deinys says that her research at UCF has been incredibly gratifying.

“There is a sense of community here that I found,” she says. “I joined the lab, and it felt like I found my family and that’s one of the best things to have come out of this experience. This has been one of my life’s passions, and I hope I’ll always stay with this project even after.”

Santra is encouraged by the research conducted by Pereira and Deinys, and he is hopeful it continues to bolster mangrove ecosystems.

“The UCF MISA center is dedicated to solving global problems that threaten agricultural sustainability,” he says. “We are excited to have another crop protection tool in our toolbox for protecting mangroves. I see the future of MagSun as a broad-spectrum fungicide, where GRAS (Generally Recognized As Safe) materials are empowered through nanotechnology.”

Further studies are needed to pinpoint which stressors are affecting the mangroves the most so that scientists can better preserve them, Pereira says.

“It’s very important to understand the stressors, and we need to really address if it’s a change in temperature, if it’s runoff or if it’s an additional pathogen,” he says. “In the meantime, we need to do something to prevent this damage from occurring.”

Researchers’ Credentials

Deinys graduated from BioTECH @ Richmond Heights High School, a conservation biology magnet school, where she began her research journey at Fairchild Tropical Botanic Garden and specialized in botany. In Fall 2022, Deinys joined UCF and became a member of the Santra Lab the following spring. She is an undergraduate research assistant working towards her bachelor’s degree in biotechnology.

Pereira graduated from Universidad Nacional Autónoma de Honduras with a degree in industrial chemistry. He joined Santra’s lab in 2020 and is currently a graduate research assistant and working toward his doctoral degree in chemistry.

Santra holds a doctorate in chemistry from the Indian Institute of Technology Kanpur. After graduating, he worked at the University of Florida (UF) as a postdoctoral researcher and later as a research assistant professor at the UF Department of Neurological Surgery and Particle Engineering Research Center. In 2005, Santra joined UCF as an assistant professor at the NanoScience Technology Center, the Department of Chemistry and the Burnett School of Biomedical Sciences. He is the director of the UCF Materials Innovation for Sustainable Agriculture center, a USDA-NIFA-recognized Center of Excellence.

They don’t seem to have published a paper about their work but there is this video,

After sugar-free meals, soil bacteria respire more CO2

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Scientists have found out more about how carbon cycles through the environment in a June 11, 2024 news item on ScienceDaily,

When soil microbes eat plant matter, the digested food follows one of two pathways. Either the microbe uses the food to build its own body, or it respires its meal as carbon dioxide (CO2) into the atmosphere.

Now, a Northwestern University [Illinois, US]-led research team has, for the first time, tracked the pathways of a mixture of plant waste as it moves through bacteria’s metabolism to contribute to atmospheric CO2. The researchers discovered that microbes respire three times as much CO2 from lignin carbons (non-sugar aromatic units) compared to cellulose carbons (glucose sugar units), which both add structure and support to plants’ cellular walls.

These findings help disentangle the role of microbes in soil carbon cycling — information that could help improve predictions of how carbon in soil will affect climate change.

…

Caption: Image of soil with a close-up of a bacterium and the cellular pathways involved in carbon dioxide productions. Available substrates from soil organic matter are processed through specific pathways with different amount of carbon dioxide output flux.. Credit: Aristilde Lab/Northwestern University

A June 11, 2024 Northwestern University news release (also received via email and on EurekAlert), which originated the news item, explains what this research means, Note: Links have been removed,

“The carbon pool that’s stored in soil is about 10 times the amount that’s in the atmosphere,” said Northwestern University’s Ludmilla Aristilde, who led the study. “What happens to this reservoir will have an enormous impact on the planet. Because microbes can unlock this carbon and turn it into atmospheric CO2, there is a huge interest in understanding how they metabolize plant waste. As temperatures rise, more organic matter of different types will become available in soil. That will affect the amount of CO2 that is emitted from microbial activities.”

An expert in the dynamics of organics in environmental processes, Aristilde is an associate professor of civil and environmental engineering at Northwestern’s McCormick School of Engineering and is a member of the Center for Synthetic Biology and of the Paula M. Trienens Institute for Sustainability and Energy. Caroll Mendonca, a former Ph.D. candidate in Aristilde’s laboratory, is the paper’s first author. The study includes collaborators from the University of Chicago.

‘Not all pathways are created equally’

The new study builds upon ongoing work in Aristilde’s laboratory to understand how soil stores — or releases — carbon. Although previous researchers typically tracked how broken-down compounds from plant matter move individually through bacteria, Aristilde’s team instead used a mixture of these compounds to represent what bacteria are exposed to in the natural environment. Then, to track how different plant derivatives moved through a bacterium’s metabolism, the researchers tagged individual carbon atoms with isotope labels.

“Isotope labeling allowed us to track carbon atoms specific to each compound type inside the cell,” Aristilde said. “By tracking the carbon routes, we were able to capture their paths in the metabolism. That is important because not all pathways are created equally in terms of producing carbon dioxide.”

Sugar carbons in cellulose, for example, traveled through glycolytic and pentose-phosphate pathways. These pathways lead to metabolic reactions that convert digested matter into carbons to make DNA and proteins, which build the microbe’s own biomass. But aromatic, non-sugar carbons from lignin traveled a different route — through the tricarboxylic acid cycle.

“The tricarboxylic acid cycle exists in all forms of life,” Aristilde said. “It exists in plants, microbes, animals and humans. While this cycle also produces precursors for proteins, it contains several reactions that produce CO2. Most of the CO2 that gets respired from metabolism comes from this pathway.”

Expanding the findings

After tracking the routes of metabolism, Aristilde and her team performed quantitative analysis to determine the amount of CO2 produced from different types of plant matter. After consuming a mixture of plant matter, microbes respired three times as much CO2 from carbons derived from lignin compared to carbons derived from cellulose.

“Even though microbes consume these carbons at the same time, the amount of CO2 generated from each carbon type is disproportionate,” Aristilde said. “That’s because the carbon is processed via two different metabolic pathways.”

In the initial experiments, Aristilde and her team used Pseudomonas putida, a common soil bacterium with a versatile metabolism. Curious to see if their findings applied to other bacteria, the researchers studied data from previous experiments in scientific literature. They found the same relationship they discovered among plant matter, metabolism and CO2 manifested in other soil bacteria.

“We propose a new metabolism-guided perspective for thinking about how different carbon structures accessible to soil microbes are processed,” Aristilde said. “That will be key in helping us predict what will happen with the soil carbon cycle with a changing climate.”

The study, “Disproportionate carbon dioxide efflux in bacterial metabolic pathways for different organic substrates leads to variable contribution to carbon use efficiency,” was supported by the National Science Foundation (grant numbers CBET-1653092 and CBET-2022854).

Here’s a link to and a citation for the paper,

Disproportionate Carbon Dioxide Efflux in Bacterial Metabolic Pathways for Different Organic Substrates Leads to Variable Contribution to Carbon-Use Efficiency by Caroll M. Mendonca, Lichun Zhang, Jacob R. Waldbauer, and Ludmilla Aristilde. Environ. Sci. Technol. 2024, 58, 25, 11041–11052 DOI: https://doi.org/10.1021/acs.est.4c01328 Publication Date:June 11, 2024 Copyright © 2024 The Authors. Published by American Chemical Society.

This paper is open access and has a Creative Commons licence: CC-BY-NC-ND 4.0..

Electricity (electrodeposition) could help fight coastal (beach) erosion

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I live in a coastal region and a few months ago our local municipal voted down an initiative that included some mitigation for beach erosion. So, this research caught my eye.

Caption: An artistic impression of how electricity could be used to strengthen coastlines. Credit: Northwestern University

An August 22, 2024 news item on phys.org announces an unexpected approach to dealing with coastal erosion,

New research from Northwestern University has systematically proven that a mild zap of electricity can strengthen a marine coastline for generations—greatly reducing the threat of erosion in the face of climate change and rising sea levels.

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An August 22, 2024 Northwestern University news release (received via email and also found on EurekAlert) by Amanda Morris, which originated the news item, delves further into the topic, Note: Links have been removed,

In the new study, researchers took inspiration from clams, mussels and other shell-dwelling sea life, which use dissolved minerals in seawater to build their shells.

Similarly, the researchers leveraged the same naturally occurring, dissolved minerals to form a natural cement between sea-soaked grains of sand. But, instead of using metabolic energy like mollusks do, the researchers used electrical energy to spur the chemical reaction.

In laboratory experiments, a mild electrical current instantaneously changed the structure of marine sand, transforming it into a rock-like, immoveable solid. The researchers are hopeful this strategy could offer a lasting, inexpensive and sustainable solution for strengthening global coastlines.

The study will be published on Thursday (Aug. 22 [2024]) in the journal Communications Earth and the Environment, a journal published by Nature Portfolio.

“Over 40% of the world’s population lives in coastal areas,” said Northwestern’s Alessandro Rotta Loria, who led the study. “Because of climate change and sea-level rise, erosion is an enormous threat to these communities. Through the disintegration of infrastructure and loss of land, erosion causes billions of dollars in damage per year worldwide. Current approaches to mitigate erosion involve building protection structures or injecting external binders into the subsurface.

“My aim was to develop an approach capable of changing the status quo in coastal protection — one that didn’t require the construction of protection structures and could cement marine substrates without using actual cement. By applying a mild electric stimulation to marine soils, we systematically and mechanistically proved that it is possible to cement them by turning naturally dissolved minerals in seawater into solid mineral binders — a natural cement.”

Rotta Loria is the Louis Berger Assistant Professor of Civil and Environmental Engineering at Northwestern’s McCormick School of Engineering. Andony Landivar Macias, a former Ph.D. candidate in Rotta Loria’s laboratory, is the paper’s first author. Steven Jacobsen, a mineralogist and professor of Earth and planetary sciences in Northwestern’s Weinberg College of Arts and Sciences, also co-authored the study.

Sea walls, too, erode

From intensifying rainstorms to rising sea levels, climate change has created conditions that are gradually eroding coastlines. According to a 2020 study by the European commission’s Joint Research Centre, nearly 26% of the Earth’s beaches will be washed away by the end of this century.

To mitigate this issue, communities have implemented two main approaches: building protection structures and barriers, such as sea walls, or injecting cement into the ground to strengthen marine substrates, widely consisting of sand. But multiple problems accompany these strategies. Not only are these conventional methods extremely expensive, they also do not last.

“Sea walls, too, suffer from erosion,” Rotta Loria said. “So, over time, the sand beneath these walls erodes, and the walls can eventually collapse. Oftentimes, protection structures are made of big stones, which cost millions of dollars per mile. However, the sand beneath them can essentially liquify because of a number of environmental stressors, and these big rocks are swallowed by the ground beneath them.

“Injecting cement and other binders into the ground has a number of irreversible environmental drawbacks. It also typically requires high pressures and significant interconnected amounts of energy.”

Turning ions into glue

To bypass these issues, Rotta Loria and his team developed a simpler technique, inspired by coral and mollusks. Seawater naturally contains a myriad of ions and dissolved minerals. When a mild electrical current (2 to 3 volts) is applied to the water, it triggers chemical reactions. This converts some of these constituents into solid calcium carbonate — the same mineral mollusks use to build their shells. Likewise, with a slightly higher voltage (4 volts), these constituents can be predominantly converted into magnesium hydroxide and hydromagnesite, a ubiquitous mineral found in various stones.

When these minerals coalesce in the presence of sand, they act like a glue, binding the sand particles together. In the laboratory, the process also worked with all types of sands — from common silica and calcareous sands to iron sands, which are often found near volcanoes.

“After being treated, the sand looks like a rock,” Rotta Loria said. “It is still and solid, instead of granular and incohesive. The minerals themselves are much stronger than concrete, so the resulting sand could become as strong and solid as a sea wall.”

While the minerals form instantaneously after the current is applied, longer electric stimulations garner more substantial results. “We have noticed remarkable outcomes from just a few days of stimulations,” Rotta Loria said. “Then, the treated sand should stay in place, without needing further interventions.”

Ecofriendly and reversible

Rotta Loria predicts the treated sand should keep its durability, protecting coastlines and property for decades.

Rotta Loria also says there is no need to worry negative effects on sea life. The voltages used in the process are too mild to feel. Other researchers have used similar processes to strengthen undersea structures or even restore coral reefs. In those scenarios, no sea critters were harmed.

And, if communities decide they no longer want the solidified sand, Rotta Loria has a solution for that, too, as the process is completely reversible. When the battery’s anode and cathode electrodes are switched, the electricity dissolves the minerals — effectively undoing the process.

“The minerals form because we are locally raising the pH of the seawater around cathodic interfaces,” Rotta Loria said. “If you switch the anode with the cathode, then localized reductions in pH are involved, which dissolve the previously precipitated minerals.”

Competitive cost, countless applications

The process offers an inexpensive alternative to conventional methods. After crunching the numbers, Rotta Loria’s team estimates that his process costs just $3 to $6 per cubic meter of electrically cemented ground. More established, comparable methods, which use binders to adhere and strengthen sand, cost up to $70 for the same unit volume.

Research in Rotta Loria’s lab shows this approach also can heal cracked structures made of reinforced concrete. Much of the existing shoreside infrastructure is made of reinforced concrete, which disintegrates due to complex effects caused by sea-level rise, erosion and extreme weather. And if these structures crack, the new approach bypasses the need to fully rebuild the infrastructure. Instead, one pulse of electricity can heal potentially destructive cracks.

“The applications of this approach are countless,” Rotta Loria said. “We can use it to strengthen the seabed beneath sea walls or stabilize sand dunes and retain unstable soil slopes. We could also use it to strengthen protection structures, marine foundations and so many other things. There are many ways to apply this to protect coastal areas.”

Next, Rotta Loria’s team plans to test the technique outside of the laboratory and on the beach.

The study, “Electrodeposition of calcareous cement from seawater in marine silica sands,” was supported by the Army Research Office (grant number W911NF2210291) and Northwestern’s Center for Engineering Sustainability and Resilience.

Here’s a link to and a citation for the paper,

Electrodeposition of calcareous cement from seawater in marine silica sands by Andony Landivar Macias, Steven D. Jacobsen & Alessandro F. Rotta Loria. Communications Earth & Environment volume 5, Article number: 442 (2024) DOI: https://doi.org/10.1038/s43247-024-01604-3 Published: 22 August 2024

This paper is open access.

Using copper to mitigate climate change?

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A July 4, 2024 news item on phys.org announces research into copper that mitigates climate change,

Carbon in the atmosphere is a major driver of climate change. Now researchers from McGill University have designed a new catalyst for converting carbon dioxide (CO2) into methane—a cleaner source of energy—using tiny bits of copper called nanoclusters. While the traditional method of producing methane from fossil fuels introduces more CO2 into the atmosphere, the new process, electrocatalysis, does not.

…

A July 4, 2024 Canadian Light Source (CLS) news release (also received via email) by Rowan Hollinger, which originated the news item, delves further into the research, Note: A link has been removed,

“On sunny days you can use solar power, or when it’s a windy day you can use that wind to produce renewable electricity, but as soon as you produce that electricity you need to use it,” says Mahdi Salehi, Ph.D. candidate at the Electrocatalysis Lab at McGill University. “But in our case, we can use that renewable but intermittent electricity to store the energy in chemicals like methane.”

By using copper nanoclusters, says Salehi, carbon dioxide from the atmosphere can be transformed into methane and once the methane is used, any carbon dioxide released can be captured and “recycled” back into methane. This would create a closed “carbon loop” that does not emit new carbon dioxide into the atmosphere. The research, published recently in the journal Applied Catalysis B: Environment and Energy, was enabled by the Canadian Light Source (CLS) at the University of Saskatchewan (USask).

“In our simulations, we used copper catalysts with different sizes, from small ones with only 19 atoms to larger ones with 1000 atoms,” says Salehi. “We then tested them in the lab, focusing on how the sizes of the clusters influenced the reaction mechanism.”

“Our top finding was that extremely small copper nanoclusters are very effective at producing methane,” continues Salehi. “This was a significant discovery, indicating that the size and structure of the copper nanoclusters play a crucial role in the reaction’s outcome.”

The team plans to continue refining their catalyst to make it more efficient and investigate its large-scale, industrial applications. Their hope is that their findings will open new avenues for producing clean, sustainable energy.

…

Researcher Mahdi Salehi describes his work in a video provided by the Canadian Light Source (CLS),

Here’s a link to and a citation for the paper,

Copper nanoclusters: Selective CO2 to methane conversion beyond 1 A/cm² by Mahdi Salehi, Hasan Al-Mahayni, Amirhossein Farzi, Morgan McKee, Sepideh Kaviani, Elmira Pajootan, Roger Lin, Nikolay Kornienko, Ali Seifitokaldani. Applied Catalysis B: Environment and Energy Volume 353, 15 September 2024, 124061 DOI: https://doi.org/10.1016/j.apcatb.2024.124061 Available online 9 April 2024, Version of Record 12 April 2024.

This paper is open access. Under a Creative Commons license

It’s all about the cellulose and the graphite: using fallen leaves as the basis for medical and laboratory sensors

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Caption: Sensor printed on leaf by CO2 laser. Credit: Bruno Janegitz

A May 9, 2024 news item on phys.org announces work which makes use of fallen leaves, Note: A link has been removed,

Fabrication of sensors by 3D printing combines speed, freedom of design, and the possibility of using waste as a substrate. Various results have been obtained in a circular economy mode, whereby residues usually thrown away are instead used as low-cost resources.

A highly creative solution involving the printing of electrochemical sensors on fallen tree leaves has now been presented by a team of researchers in Brazil led by Bruno Janegitz, a professor at the Federal University of São Carlos (UFSCar) and head of its Laboratory for Sensors, Nanomedicines, and Nanostructured Materials (LSNANO), and Thiago Paixão, a professor at the University of São Paulo (USP) and head of its Electronic Tongues and Chemical Sensors Lab (L2ESQ).

…

A May 8, 2024 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) press release (also on EurekAlert but published May 9, 2024) by José Tadeu Arantes, Note: Links have been removed,

…

The initiative was supported by FAPESP and highlighted in an article published in the journal ACS Sustainable Chemistry & Engineering.

“We used a CO2 [carbon dioxide] laser to print the design of interest on a leaf by means of pyrolysis and carbonization. We thereby obtained an electrochemical sensor for use in determining levels of dopamine and paracetamol. It’s very easy to operate. A drop of the solution containing one of these compounds is placed on the sensor, and the potentiostat to which it’s coupled displays the concentration,” Janegitz said.

Simply put, the laser beam burns the leaf in a pyrolytic process that converts its cellulose into graphite [emphasis mine], and the graphite body is printed on the leaf in a shape suited to functioning as a sensor. During the fabrication process, the parameters of the CO2 laser, including laser power, pyrolysis scan rate and scan gap, are systematically adjusted to achieve optimal outcomes.

“The sensors were characterized by morphological and physicochemical methods, permitting exhaustive exploration of the novel carbonized surface generated on the leaves,” Janegitz said.

“Furthermore, the applicability of the sensors was confirmed by tests involving the detection of dopamine and paracetamol in biological and pharmaceutical samples. For dopamine, the system proved efficient in a linear range of 10–1,200 micromoles per liter, with a detection limit of 1.1 micromole per liter. For paracetamol, the system worked well in a linear range of 5-100 micromoles per liter, with a detection limit of 0.76.”

In the tests involving dopamine and paracetamol, conducted as proof of concept, the electrochemical sensors derived from fallen tree leaves attained a satisfactory analytical performance and noteworthy reproducibility, highlighting their potential as an alternative to conventional substrates.

Substituting fallen tree leaves for conventional materials yields significant gains in terms of cost-cutting and above all environmental sustainability. “The leaves would have been incinerated, or at best composted. Instead, they were used as a substrate for high value-added devices in a major advancement for the fabrication of next-generation electrochemical sensors,” Janegitz said. 

…

There’s also this, “The Agency FAPESP licenses news via Creative Commons (CC-BY-NC-ND) so that they can be republished free of charge and in a simple way by other digital or printed vehicles.”

Here’s a link to and a citation for the paper,

Green Fabrication and Analytical Application of Disposable Carbon Electrodes Made from Fallen Tree Leaves Using a CO2Laser by Rodrigo Vieira Blasques, Jéssica Rocha Camargo, William Barros Veloso, Gabriel Negrão Meloni, Fernando Amaral Fernandes, Beatriz Fernandes Germinare, Luiz Ricardo Guterres e Silva, Abner de Siervo, Thiago Regis Longo Cesar Paixão, and Bruno Campos Janegitz. ACS Sustainable Chem. Eng. 2024, 12, 8, 3061–3072 DOI: https://doi.org/10.1021/acssuschemeng.3c06526 Publication Date: February 13, 2024 Copyright © 2024 American Chemical Society

This paper is behind a paywall.

Cotton gin waste and self-embedding silver nanoparticles

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This work may lead to new uses for cotton waste products according to an April 10, 2024 news item on phys.org,

Cotton gin waste, also known as cotton gin trash, is a byproduct of the cotton ginning process and occurs when the cotton fibers are separated from the seed boll. For cotton gin waste, the treasure is its hidden potential to transform silver ions into silver nanoparticles and create a new hybrid material that could be used to add antimicrobial properties to consumer products, like aerogels, packaging, or composites.

…

An April 9, 2024 US Dept. of Agriculture (USDA) Agricultural Research Service (ARS) news release, which originated the news item, provides more detail, Note: Links have been removed,

Silver nanoparticles are highly sought-after products in the nanotechnology industry because of their antibacterial, antifungal, antiviral, electrical, and optical properties. These nanoparticles have an estimated global production of 500 tons per year and are widely applied to consumer goods such as textiles, coatings, paints, pigments, electronics, optics, and packaging.

In a study published in ACS Omega, researchers from the United States Department of Agriculture (USDA)’s Agricultural Research Service (ARS) revealed the ability of cotton gin waste to synthesize and generate silver nanoparticles in the presence of silver ions.

“Our method not only lets cotton gin waste act as chemical agents for producing silver nanoparticles, which makes it cost-effective and environmentally friendly but also enables embedding the nanoparticles within the cotton gin waste matrix,” said Sunghyun Nam, research engineer at ARS’s Cotton Chemistry and Utilization Research Unit in New Orleans. “By embedding them in the cotton gin waste, these materials acquire antimicrobial properties.”

Nam said the researchers used a simple heat treatment of cotton gin waste materials in water containing silver ions that produced silver nanoparticles without the need for additional chemical agents.

This finding is significant since making silver nanoparticles usually requires chemical agents which can be costly and pose environmental concerns. Embedding nanoparticles into a material can also be challenging.

Developing nanoparticle embedding technology is not new for Nam and her team. They previously developed washable antimicrobial wipes by using raw cotton fiber that produced silver nanoparticles inside the fiber. The embedded silver nanoparticles can continue to kill harmful bacteria wash after wash.

Large quantities of cotton gin waste are generated annually, and the cotton ginning industry is always seeking new sustainable processes that upcycle crop residue.

“Our research paves the way for new material applications of cotton gin waste that can protect against microbial contamination,” said Nam.

A provisional patent application on the self-embedding silver nanoparticle biomass waste compositions has recently been filed.

The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.

Despite the date of the news release, this is a relatively old paper; here’s a link to and a citation,

Unveiling the Hidden Value of Cotton Gin Waste: Natural Synthesis and Hosting of Silver Nanoparticles by Sunghyun Nam*, Michael Easson, Jacobs H. Jordan, Zhongqi He, Hailin Zhang, Michael Santiago Cintrón, and SeChin Chang. ACS Omega 2023, 8, 34, 31281–31292 DOI: https://doi.org/10.1021/acsomega.3c03653 Publication Date: August 9, 2023 © 2023 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY-NC-ND 4.0.

As you can see from the Creative Commons licence, this paper is open access.

Reusable ‘sponge’ for soaking up marine oil spills—even in northern waters

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A May 28, 2024 news item on phys.org announces some new research into sponges, a topic of some interest where oil spill cleanups are concerned,

Oil spills, if not cleaned up quickly and effectively, can cause lasting damage to marine and coastal environments. That’s why a team of North American researchers are developing a new sponge-like material that is not only effective at grabbing and holding oil on its surface (adsorption), but can be reused again and again—even in icy Canadian waters….

…

A May 27, 2024 Canadian Light Source (CLS) news release (also received via email) by Rowan Hollinger provides some details, Note: CNF can be cellulose nanofibers, cellulose nanofibrils, or, it’s sometimes called, nanofibrillated cellulose (NFC) (see Nanocellulose Wikipedia entry),,

The special material – called CNF-SP aerogel — combines a biodegradable cellulose-based material with a substance called spiropyran, a light-sensitive material. Spiropyran has a unique ‘switchable’ property that allows the aerogel to go between being oil-sorbent and oil-repellent, just like a kitchen sponge that can be used to soak up and squeeze out water.

“Once spiropyran has been added to the aerogel, after each usage we just switch the light condition,” explains Dr. Baiyu Helen Zhang, professor and Canada Research Chair at Memorial University, Newfoundland. “We used the aerogel as an oil sorbent under visible light. After oil adsorption, we switched the light condition to UV light. This switch helped the sponge to release the oil.”

And the material continues soaking up and releasing oil, even when the water temperature drops, according to Dr. Xiujuan Chen, an assistant professor at University of Texas – Arlington.

“We found that when we tested the oil sorbent’s performance under different kinds of environmental conditions, it had a very good performance in a cold environment. This is quite useful for cold winter seasons, particularly for Canada.”

The researchers used the CLS’s Mid-IR beamline to examine the characteristics of the aerogel before and after exposing it to visible and UV light. From here, the researchers are looking to scale up their research with large pilot studies and even testing the material in the field.

“The CLS has very unique infrastructure that supports students and researchers like us to conduct many kinds of very exciting research and to contribute to scientific knowledge and engineering applications,” says Zhang.

Here’s a link to and a citation for the paper,

Development of a spiropyran-assisted cellulose aerogel with switchable wettability as oil sorbent for oil spill cleanup by Hongjie Wang, Xiujuan Chen, Bing Chen, Yuming Zhao, Baiyu Zhang. Science of The Total Environment Volume 923, 1 May 2024, 171451 DOI: https://doi.org/10.1016/j.scitotenv.2024.171451 Available online: 2 March 2024 Version of Record: 8 March 2024

This paper is behind a paywall.

The CLS has made this video of the researchers available,

For the curious, I have many posts about sponges and, in particular, sponges for use in environmental cleanups.

Aerogels that are 3D printed from nanocellulose

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The one on the far right looks a bit like a frog (to me),

Caption: Complexity and lightness: Empa researchers have developed a 3D printing process for biodegradable cellulose aerogel. Credit: Empa

An April 4, 2024 Swiss Federal Laboratories for Materials Science and Technology (EMPA) press release (also on EurekAlert) describes some interesting possibilities for nanocellulose,

At first glance, biodegradable materials, inks for 3D printing and aerogels don’t seem to have much in common. All three have great potential for the future, however: “green” materials do not pollute the environment, 3D printing can produce complex structures without waste, and ultra-light aerogels are excellent heat insulators. Empa researchers have now succeeded in combining all these advantages in a single material. And their cellulose-based, 3D-printable aerogel can do even more.

The miracle material was created under the leadership of Deeptanshu Sivaraman, Wim Malfait and Shanyu Zhao from Empa’s Building Energy Materials and Components laboratory, in collaboration with the Cellulose & Wood Materials and Advanced Analytical Technologies laboratories as well as the Center for X-ray Analytics. Together with other researchers, Zhao and Malfait had already developed a process for printing silica aerogels in 2020. No trivial task: Silica aerogels are foam-like materials, highly open porous and brittle. Before the Empa development, shaping them into complex forms had been pretty much impossible. “It was the logical next step to apply our printing technology to mechanically more robust bio-based aerogels,” says Zhao.

The researchers chose the most common biopolymer on Earth as their starting material: cellulose. Various nanoparticles can be obtained from this plant-based material using simple processing steps. Doctoral student Deeptanshu Sivaraman used two types of such nanoparticles – cellulose nanocrystals and cellulose nanofibers – to produce the “ink” for printing the bio-aerogel.

Over 80 percent water

The flow characteristics of the ink are crucial in 3D printing: Tt must be viscous enough in order to hold a three-dimensional shape before solidification. At the same time, however, it should liquefy under pressure so that it can flow through the nozzle. With the combination of nanocrystals and nanofibers, Sivaraman succeeded in doing just that: The long nanofibers give the ink a high viscosity, while the rather short crystals ensure that it has shear thinning effect so that it flows more easily during extrusion.

In total, the ink contains around twelve percent cellulose – and 88 percent water. “We were able to achieve the required properties with cellulose alone, without any additives or fillers,” says Sivaraman. This is not only good news for the biodegradability of the final aerogel products, but also for its heat-insulating properties. To turn the ink into an aerogel after printing, the researchers replace the pore solvent water first with ethanol and then with air, all while maintaining shape fidelity. “The less solid matter the ink contains, the more porous the resulting aerogel,” explains Zhao.

This high porosity and the small size of the pores make all aerogels extremely effective heat insulators. However, the researchers have identified a unique property in the printed cellulose aerogel: It is anisotropic. This means its strength and thermal conductivity are direction-dependent. “The anisotropy is partly due to the orientation of the nanocellulose fibers and partly due to the printing process itself,” says Malfait. This allows the researchers to control in which axis the printed aerogel piece should be particularly stable or particularly insulating. Such precisely crafted insulating components could be used in microelectronics, where heat should only be conducted in a certain direction.

A lot of potential applications in medicine

Although the original research project, which was funded by the Swiss National Science Foundation (SNSF), was primarily interested in thermal insulation, the researchers quickly saw another area of application for their printable bio-aerogel: medicine. As it consists of pure cellulose, the new aerogel is biocompatible with living tissues and cells. Its porous structure is able to absorb drugs and then release them into the body over a long period of time. And 3D printing offers the possibility of producing precise shapes that could, for instance, serve as scaffolds for cell growth or as implants.

A particular advantage is that the printed aerogel can be rehydrated and re-dried several times after the initial drying process without losing its shape or porous structure. In practical applications, this would make the material easier to handle: It could be stored and transported in dry form and only be soaked in water shortly before use. When dry, it is not only light and convenient to handle, but also less susceptible to bacteria – and does not have to be elaborately protected from drying out. “If you want to add active ingredients to the aerogel, this can be done in the final rehydration step immediately before use,” says Sivaraman. “Then you don’t run the risk of the medication losing its effectiveness over time or if it is stored incorrectly.”

The researchers are also working on drug delivery from aerogels in a follow-up project – with less focus on 3D printing for now. Shanyu Zhao is collaborating with researchers from Germany and Spain on aerogels made from other biopolymers, such as alginate and chitosan, derived from algae and chitin respectively. Meanwhile, Wim Malfait wants to further improve the thermal insulation of cellulose aerogels. And Deeptanshu Sivaraman has completed his doctorate and has since joined the Empa spin-off Siloxene AG, which creates new hybrid molecules based on silicon.

Fascinating work and here’s a link to and a citation for the paper,

Additive Manufacturing of Nanocellulose Aerogels with Structure-Oriented Thermal, Mechanical, and Biological Properties by Deeptanshu Sivaraman, Yannick Nagel, Gilberto Siqueira, Parth Chansoria, Jonathan Avaro, Antonia Neels, Gustav Nyström, Zhaoxia Sun, Jing Wang, Zhengyuan Pan, Ana Iglesias-Mejuto, Inés Ardao, Carlos A. García-González, Mengmeng Li, Tingting Wu, Marco Lattuada, Wim J. Malfait, Shanyu Zhao. Advanced Science DOI: https://doi.org/10.1002/advs.202307921 First published: 13 March 2024

This paper is open access.

You can find Siloxene AG here.