Monthly Archives: August 2024

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,

Using a new computer program to ‘paint’ the structure of molecules in the style of a famous Dutch artist

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Figure 2: a) “Neoplastic” diagram of the porphyrin core of the classic nonplanar 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraphenylporphyrin (CCDC: RONROB), alongside two representations of this same molecule—b) the crystal structure thermal ellipsoid plot and (c) skeletal model.28 This porphyrin shape is primarily saddled and a little ruffled, resulting in S4 symmetry … [downloaded from https://onlinelibrary.wiley.com/doi/10.1002/ange.202403754]

A July 12, 2024 news item on ScienceDaily describes a fascinating computer program developed by scientists at Trinity College Dublin,

Scientists from Trinity College Dublin have created a computer program that “paints” the structure of molecules in the style of famous Dutch artist, Piet Mondrian, whose beautiful artworks will be instantly recognizable to many.

Mondrian’s style, whereby he used blocks of primary colors separated by lines of various widths on a white background, has been extensively copied or used as an inspiration in modern culture. But his deceptively simple artworks have also fascinated scientists for decades, finding niche applications in mathematics and statistics.

And now, researchers from the School of Chemistry are opening eyes and minds to the beauty of molecular structure, as well as posing new questions about the form and function of the molecules themselves.

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A July 15, 2024 Trinity College Dublin press release (also on EurekAlert but published July 12, 2024), which originated the news item, provides more details about the work,

Their computer program, which can be accessed at http://www.sengegroup.eu/nsd, produces a Mondrianesque plot of any molecule. It does so by following an artistic algorithm that marries the laws of chemistry that describe the 3D structure of a molecule based on its components with the 2D style of one of the most influential painters of the Modern era.

For the scientist, it helps to rapidly assess and demonstrate molecular symmetry, allowing for deeper insights than would emerge from traditional representations. And for the artist, it provides a visually pleasing image of contrasting interpretations of symmetry, hopefully providing inspiration for the incorporation of scientific ideas into work. 

Mathias O Senge, Professor of Organic Chemistry in Trinity and Hans Fischer Senior Fellow at the Institute for Advanced Study of TU Munich [Technische Universität München or Technical University of Munich] is the senior author of a just-published article in the leading international journal, Angewandte Chemie, in which this creation is shared with the world. He said:

“For some years we have been working on this project, initially for fun, to output the structure of a molecule in an artistically pleasing manner as a painting in the style of Mondrian. The ‘paintings’ obtained are unique for each molecule and juxtapose what Mondrian and others aimed to do with the De Stijl artistic movement.

“Symmetry and shape are essential aspects of molecular structure and how we interpret molecules and their properties, but very often relationships between chemical structure and derived values are obscured. Taking our inspiration from Mondrian’s Compositions, we have depicted the symmetry information encoded within 3D data as blocks of colour, to show clearly how chemical arguments may contribute to symmetry.” 

Christopher Kingsbury, postdoctoral researcher in TBSI, who conceived the project, is first author of the journal article. He said: “In chemistry, it is useful to have a universal way of displaying molecular structure, so as to help ‘blueprint’ how a molecule is likely to behave in different environments and how it may react and change shape when in the presence of other molecules. But a certain amount of nuance is inevitably lost.

“This concept of increasing abstraction by removing minor details and trying to present a general form is mimicked by the early work of Mondrian and in some senses this is what scientists intuitively do when reducing complex phenomena to a ‘simpler truth’. Thanks to our new approach very complex science is fed through an artistic lens, which might make it more accessible to a wider range of people.”  

In recent years Professor Senge and his team have greatly enhanced our understanding of porphyrins, a unique class of intensely coloured pigments – also known as the “colours of life”. In one piece of work they created a suite of new biological sensors by chemically re-engineering these pigments to act like tiny Venus flytraps and grab specific molecules, such as pollutants. And now the new direction, in which science and art collide, may further develop our understanding of how porphyrins work.

“Great art gives us a new perspective on the world,” added Prof. Senge. “As a pastiche, this art may allow us to look at familiar molecules, such as porphyrins, in a new light, and help us to better understand how their shape and properties are intertwined. More generally, we believe that contemporary initiatives in ‘Art and Science’ require a transformative break of discipline boundaries and merger to ‘ArtScience’. There is a subtle interplay between science and art and mixing of both aspects in our respective fields of endeavour and this should be a focus for future developments in both areas.”

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

Molecular Symmetry and Art: Visualizing the Near-Symmetry of Molecules in Piet Mondrian’s De Stijl by Dr. Christopher J. Kingsbury, Prof. Dr. Mathias O. Senge. Angewandte Chemie DOI: https://doi.org/10.1002/ange.202403754 Volume 136, Issue 25 June 17, 2024 e202403754 First published: 15 April 2024

This paper is open access.

Spontaneous assembly of nanocubes in water lock like tiny floating checkerboards

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This is what the tiny checkerboards look like,

SEM image of a checkerboard pattern created by self-assembly of the nanocubes. Scale bar = 500 nm, inset = 100 nm. Image by Wang et al., Nature Communications [downloaded from https://today.ucsd.edu/story/nanosized-blocks-spontaneously-assemble-in-water-to-create-tiny-floating-checkerboards]

A June 13, 2024 news item on ScienceDaily announces the research that resulted in the checkerboards,

Researchers have engineered nanosized cubes that spontaneously form a two-dimensional checkerboard pattern when dropped on the surface of water. The work, published in Nature Communications, presents a simple approach to create complex nanostructures through a technique called self-assembly.

“It’s a cool way to get materials to build themselves,” said study co-senior author Andrea Tao, a professor in the Aiiso Yufeng Li Family Department of Chemical and Nano Engineering at the University of California San Diego. “You don’t have to go into a nanofabrication lab and do all these complex and precise manipulations.”

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A June 13, 2024 University of California – San Diego news release (also on EurekAlert) by Liezel Labios, which originated the news item, provides more detail about the work, Note: A link has been removed,

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Each nanocube is composed of a silver crystal with a mixture of hydrophobic (oily) and hydrophilic (water-loving) molecules attached to the surface. When a suspension of these nanocubes is introduced to a water surface, they arrange themselves such that they touch at their corner edges. This arrangement creates an alternating pattern of solid cubes and empty spaces, resulting in a checkerboard pattern.

The self-assembly process is driven by the surface chemistry of the nanocubes. A high density of hydrophobic molecules on the surface brings the cubes together to minimize their interaction with water. Meanwhile, the long chains of hydrophilic molecules cause enough repulsion to create voids between the cubes, creating the checkerboard pattern.

To fabricate the structure, researchers applied drops of the nanocube suspension onto a petri dish containing water. The resulting checkerboard can be easily transferred to a substrate by dipping the substrate into the water and slowly withdrawing it, allowing the nanostructure to coat it.

This study stems from a collaborative effort between multiple research groups that are part of the UC San Diego Materials Research Science and Engineering Center (MRSEC). The work featured a synergistic combination of computational and experimental techniques. “We’ve built a continuous feedback loop between our computations and experiments,” said Tao. “We used computer simulations to help us design the materials at the nanoscale and predict how they will behave. We also used our experimental results in the lab to validate the simulations, fine tune them and build a better model.”

In designing the material, researchers chose silver crystal nanocubes due to the Tao lab’s expertise in their synthesis. Determining the optimal surface chemistry required extensive computational experimentation, which was led by Gaurav Arya, a professor in the Department of Mechanical Engineering and Materials Science at Duke University and co-senior author of the study. The simulations identified the best molecules to attach to the nanocubes and predicted how the cubes would interact and assemble on the water surface. The simulations were iteratively refined using experimental data obtained by Tao’s lab. Electron microscopy performed by the lab of study co-author Alex Frañó, a professor in the Department of Physics at UC San Diego, confirmed the formation of the desired checkerboard structures.

Tao envisions applications for the nanocube checkerboard in optical sensing. “Such a nanostructure can manipulate light in interesting ways,” she explained. “The spaces between the cubes, particularly near the corner edges where the cubes connect, can act as tiny hotspots that focus or trap light. That could be useful for making new types of optical elements like nanoscale filters or waveguides.”

The researchers plan to explore the optical properties of the checkerboard in future studies.

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

Self-assembly of nanocrystal checkerboard patterns via non-specific interactions by Yufei Wang, Yilong Zhou, Quanpeng Yang, Rourav Basak, Yu Xie, Dong Le, Alexander D. Fuqua, Wade Shipley, Zachary Yam, Alex Frano, Gaurav Arya & Andrea R. Tao. Nature Communications volume 15, Article number: 3913 (2024) DOI: https://doi.org/10.1038/s41467-024-47572-2 Published0: 9 May 2024

This paper is open access.

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.

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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..

New approach to cartilage regeneration

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Not long after announcing their new work on cartilage and ‘dancing molecules’, Samuel I. Stupp and his team at Northwestern University (Chicago, Illinois) have announced work with a new material that does not have dancing molecules in a study using animal models. It’s here in an August 5, 02024 Northwestern University news release (also on EurekAlert and on SciTechDaily and received by email) by Amanda Morris, Note: Links have been removed,

Northwestern University scientists have developed a new bioactive material that successfully regenerated high-quality cartilage in the knee joints of a large-animal model.

Although it looks like a rubbery goo, the material is actually a complex network of molecular components, which work together to mimic cartilage’s natural environment in the body. 

In the new study, the researchers applied the material to damaged cartilage in the animals’ knee joints. Within just six months, the researchers observed evidence of enhanced repair, including the growth of new cartilage containing the natural biopolymers (collagen II and proteoglycans), which enable pain-free mechanical resilience in joints.

With more work, the researchers say the new material someday could potentially be used to prevent full knee replacement surgeries, treat degenerative diseases like osteoarthritis and repair sports-related injuries like ACL [anterior cruciate ligament] tears.

The study will be published during the week of August 5 [2024] in the Proceedings of the National Academy of Sciences.

“Cartilage is a critical component in our joints,” said Northwestern’s Samuel I. Stupp, who led the study. “When cartilage becomes damaged or breaks down over time, it can have a great impact on people’s overall health and mobility. The problem is that, in adult humans, cartilage does not have an inherent ability to heal. Our new therapy can induce repair in a tissue that does not naturally regenerate. We think our treatment could help address a serious, unmet clinical need.”

A pioneer of regenerative nanomedicine, Stupp is Board of Trustees Professor of Materials Science and Engineering, Chemistry, Medicine and Biomedical Engineering at Northwestern, where he is founding director of the Simpson Querrey Institute for BioNanotechnology and its affiliated center, the Center for Regenerative Nanomedicine. Stupp has appointments in the McCormick School of Engineering, Weinberg College of Arts and Sciences and Feinberg School of Medicine. Jacob Lewis, a former Ph.D. student in Stupp’s laboratory, is the paper’s first author.

What’s in the material?

The new study follows recently published work from the Stupp laboratory, in which the team used “dancing molecules” to activate human cartilage cells to boost the production of proteins that build the tissue matrix. Instead of using dancing molecules, the new study evaluates a hybrid biomaterial also developed in Stupp’s lab. The new biomaterial comprises two components: a bioactive peptide that binds to transforming growth factor beta-1 (TGFb-1) — an essential protein for cartilage growth and maintenance — and modified hyaluronic acid, a natural polysaccharide present in cartilage and the lubricating synovial fluid in joints. 

“Many people are familiar with hyaluronic acid because it’s a popular ingredient in skincare products,” Stupp said. “It’s also naturally found in many tissues throughout the human body, including the joints and brain. We chose it because it resembles the natural polymers found in cartilage.”

Stupp’s team integrated the bioactive peptide and chemically modified hyaluronic acid particles to drive the self-organization of nanoscale fibers into bundles that mimic the natural architecture of cartilage. The goal was to create an attractive scaffold for the body’s own cells to regenerate cartilage tissue. Using bioactive signals in the nanoscale fibers, the material encourages cartilage repair by the cells, which populate the scaffold.

Clinically relevant to humans

To evaluate the material’s effectiveness in promoting cartilage growth, the researchers tested it in sheep with cartilage defects in the stifle joint, a complex joint in the hind limbs similar to the human knee. This work was carried out in the laboratory of Mark Markel in the School of Veterinary Medicine at the University of Wisconsin–Madison. 

According to Stupp, testing in a sheep model was vital. Much like humans, sheep cartilage is stubborn and incredibly difficult to regenerate. Sheep stifles and human knees also have similarities in weight bearing, size and mechanical loads.

“A study on a sheep model is more predictive of how the treatment will work in humans,” Stupp said. “In other smaller animals, cartilage regeneration occurs much more readily.”

In the study, researchers injected the thick, paste-like material into cartilage defects, where it transformed into a rubbery matrix. Not only did new cartilage grow to fill the defect as the scaffold degraded, but the repaired tissue was consistently higher quality compared to the control.

A lasting solution

In the future, Stupp imagines the new material could be applied to joints during open-joint or arthroscopic surgeries. The current standard of care is microfracture surgery, during which surgeons create tiny fractures in the underlying bone to induce new cartilage growth.

“The main issue with the microfracture approach is that it often results in the formation of fibrocartilage — the same cartilage in our ears — as opposed to hyaline cartilage, which is the one we need to have functional joints,” Stupp said. “By regenerating hyaline cartilage, our approach should be more resistant to wear and tear, fixing the problem of poor mobility and joint pain for the long term while also avoiding the need for joint reconstruction with large pieces of hardware.”

The study, “A bioactive supramolecular and covalent polymer scaffold for cartilage repair in a sheep model,” was supported by the Mike and Mary Sue Shannon Family Fund for Bio-Inspired and Bioactive Materials Systems for Musculoskeletal Regeneration.

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

A bioactive supramolecular and covalent polymer scaffold for cartilage repair in a sheep model by Jacob A. Lewis, Brett Nemke, Yan Lu, Nicholas A. Sather, Mark T. McClendon, Michael Mullen, Shelby C. Yuan, Sudheer K. Ravuri, Jason A. Bleedorn, Marc J. Philippon, Johnny Huard, Mark D. Markel, and Samuel I. Stupp. Proceedings ot the National Academy of Sciences (PNAS) 121 (33) e2405454121 DOI: https://doi.org/10.1073/pnas.2405454121 August 6, 2024

This paper is behind a paywall.

Healing cartilage damage with ‘dancing molecules’

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A July 26, 2024 Northwestern University (Chicago, Illinois) news release (also on EurekAlert) by Amanda Morris describes a new application for ‘dancing molecules’, Note 1: Links have been removed; Note 2: These are ‘in vitro’ (petri dish) experiments ,

In November 2021, Northwestern University researchers introduced an injectable new therapy, which harnessed fast-moving “dancing molecules,” to repair tissues and reverse paralysis after severe spinal cord injuries.

Now, the same research group has applied the therapeutic strategy to damaged human cartilage cells. In the new study, the treatment activated the gene expression necessary to regenerate cartilage within just four hours. And, after only three days, the human cells produced protein components needed for cartilage regeneration.

The researchers also found that, as the molecular motion increased, the treatment’s effectiveness also increased. In other words, the molecules’ “dancing” motions were crucial for triggering the cartilage growth process.

…

“When we first observed therapeutic effects of dancing molecules, we did not see any reason why it should only apply to the spinal cord,” said Northwestern’s Samuel I. Stupp, who led the study. “Now, we observe the effects in two cell types that are completely disconnected from one another — cartilage cells in our joints and neurons in our brain and spinal cord. This makes me more confident that we might have discovered a universal phenomenon. It could apply to many other tissues.”

An expert in regenerative nanomedicine, Stupp is Board of Trustees Professor of Materials Science and Engineering, Chemistry, Medicine and Biomedical Engineering at Northwestern, where he is founding director of the Simpson Querrey Institute for BioNanotechnology and its affiliated center, the Center for Regenerative Nanomedicine. Stupp has appointments in the McCormick School of Engineering, Weinberg College of Arts and Sciences and Feinberg School of Medicine. Shelby Yuan, a graduate student in the Stupp laboratory, was primary author of the study.

Big problem, few solutions

As of 2019, nearly 530 million people around the globe were living with osteoarthritis, according to the World Health Organization. A degenerative disease in which tissues in joints break down over time, osteoarthritis is a common health problem and leading cause of disability.

In patients with severe osteoarthritis, cartilage can wear so thin that joints essentially transform into bone on bone — without a cushion between. Not only is this incredibly painful, patients’ joints also can no longer properly function. At that point, the only effective treatment is a joint replacement surgery, which is expensive and invasive.

“Current treatments aim to slow disease progression or postpone inevitable joint replacement,” Stupp said. “There are no regenerative options because humans do not have an inherent capacity to regenerate cartilage in adulthood.”

What are ‘dancing molecules’?

Stupp and his team posited that “dancing molecules” might encourage the stubborn tissue to regenerate. Previously invented in Stupp’s laboratory, dancing molecules are assemblies that form synthetic nanofibers comprising tens to hundreds of thousands of molecules with potent signals for cells. By tuning their collective motions through their chemical structure, Stupp discovered the moving molecules could rapidly find and properly engage with cellular receptors, which also are in constant motion and extremely crowded on cell membranes.

“We are beginning to see the tremendous breadth of conditions that this fundamental discovery on ‘dancing molecules’ could apply to.” — Samuel I. Stupp, materials scientist

Once inside the body, the nanofibers mimic the extracellular matrix of the surrounding tissue. By matching the matrix’s structure, mimicking the motion of biological molecules and incorporating bioactive signals for the receptors, the synthetic materials are able to communicate with cells.

“Cellular receptors constantly move around,” Stupp said. “By making our molecules move, ‘dance’ or even leap temporarily out of these structures, known as supramolecular polymers, they are able to connect more effectively with receptors.”

Motion matters

In the new study, Stupp and his team looked to the receptors for a specific protein critical for cartilage formation and maintenance. To target this receptor, the team developed a new circular peptide that mimics the bioactive signal of the protein, which is called transforming growth factor beta-1 (TGFb-1).

Then, the researchers incorporated this peptide into two different molecules that interact to form supramolecular polymers in water, each with the same ability to mimic TGFb-1. The researchers designed one supramolecular polymer with a special structure that enabled its molecules to move more freely within the large assemblies. The other supramolecular polymer, however, restricted molecular movement.

“We wanted to modify the structure in order to compare two systems that differ in the extent of their motion,” Stupp said. “The intensity of supramolecular motion in one is much greater than the motion in the other one.”

Although both polymers mimicked the signal to activate the TGFb-1 receptor, the polymer with rapidly moving molecules was much more effective. In some ways, they were even more effective than the protein that activates the TGFb-1 receptor in nature.

“After three days, the human cells exposed to the long assemblies of more mobile molecules produced greater amounts of the protein components necessary for cartilage regeneration,” Stupp said. “For the production of one of the components in cartilage matrix, known as collagen II, the dancing molecules containing the cyclic peptide that activates the TGF-beta1 receptor were even more effective than the natural protein that has this function in biological systems.”

What’s next?

Stupp’s team is currently testing these systems in animal studies and adding additional signals to create highly bioactive therapies.

“With the success of the study in human cartilage cells, we predict that cartilage regeneration will be greatly enhanced when used in highly translational pre-clinical models,” Stupp said. “It should develop into a novel bioactive material for regeneration of cartilage tissue in joints.”

Stupp’s lab is also testing the ability of dancing molecules to regenerate bone — and already has promising early results, which likely will be published later this year. Simultaneously, he is testing the molecules in human organoids to accelerate the process of discovering and optimizing therapeutic materials.  

Stupp’s team also continues to build its case to the Food and Drug Administration, aiming to gain approval for clinical trials to test the therapy for spinal cord repair.

“We are beginning to see the tremendous breadth of conditions that this fundamental discovery on ‘dancing molecules’ could apply to,” Stupp said. “Controlling supramolecular motion through chemical design appears to be a powerful tool to increase efficacy for a range of regenerative therapies.”

The study, “Supramolecular motion enables chondrogenic bioactivity of a cyclic peptide mimetic of transforming growth factor-β1,” was supported by a gift from Mike and Mary Sue Shannon to Northwestern University for research on musculoskeletal regeneration at the Center for Regenerative Nanomedicine of the Simpson Querrey Institute for BioNanotechnology.

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

Supramolecular Motion Enables Chondrogenic Bioactivity of a Cyclic Peptide Mimetic of Transforming Growth Factor-β1 by Shelby C. Yuan, Zaida Álvarez, Sieun Ruth Lee, Radoslav Z. Pavlović, Chunhua Yuan, Ethan Singer, Steven J. Weigand, Liam C. Palmer, Samuel I. Stupp. Journal of the American Chemical Society Vol 146/Issue 31 (or J. Am. Chem. Soc. 2024, 146, 31, 21555–21567) DOI: https://doi.org/10.1021/jacs.4c05170 Published July 25, 2024 Copyright © 2024 American Chemical Society

This paper is behind a paywall.

Regenerate damaged skin, cartilage, and bone with help from silkworms?

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A July 24, 2024 news item on phys.org highlights research into regenerating bone and skin, Note: A link has been removed,

Researchers are exploring new nature-based solutions to stimulate skin and bone repair.

In the cities of Trento and Rovereto in northern Italy and Bangkok in Thailand, scientists are busy rearing silkworms in nurseries. They’re hoping that the caterpillars’ silk can regenerate human tissue. For such a delicate medical procedure, only thoroughbreds will do.

“By changing the silkworm, you can change the chemistry,” said Professor Antonella Motta, a researcher in bioengineering at the University of Trento in Italy. That could, in turn, affect clinical outcomes. “This means the quality control should be very strict.”

Silk has been used in surgical sutures for hundreds of years and is now emerging as a promising nature-based option for triggering human tissue to self-regenerate. Researchers are also studying crab, shrimp and mussel shells and squid skin and bone for methods of restoring skin, bone and cartilage. This is particularly relevant as populations age.

…

A July 23, 2024 article by Gareth Willmer for Horizon Magazine, the EU (European Union) research & innovation magazine, which originated the news item, provides more details,

‘Tissue engineering is a new strategy to solve problems caused by pathologies or trauma to the organs, as an alternative to transplants or artificial device implantations,’ said Motta, noting that these interventions can often fail or expire. ‘The idea is to use the natural ability of our bodies to rebuild the tissue.’

The research forms part of the five-year EU-funded SHIFT [Shaping Innovative Designs for Sustainable Tissue Engineering Products] project that Motta coordinates, which includes universities in Europe, as well as partners in Asia and Australia. Running until 2026, the research team aim to scale up methods for regenerating skin, bone and cartilage using bio-based polymers and to get them ready for clinical trials. The goal is to make them capable of repairing larger wounds and tissue damage.

The research builds on work carried out under the earlier REMIX [Regenerative Medicine Innovation Crossing – Research and Innovation Staff Exchange in Regenerative Medicine] project, also funded by the EU, which made important advances in understanding the different ways in which these biomaterials could be used. 

Building a scaffold

Silk, for instance, can be used to form a “scaffold” in damaged tissue that then activates cells to form new tissue and blood vessels. The process could be used to treat conditions such as diabetic ulcers and lower back pain caused by spinal disc degeneration. The SHIFT team have been exploring minimally invasive procedures for treatment, such as hydrogels that can be applied directly to the skin, or injected into bone or cartilage.

The approaches using both silkworms and some of the marine organisms have great potential, said Motta. 

‘We have three or four systems with different materials that are really promising,’ she said. By the end of SHIFT, the goal is to have two or three prototypes that can be developed together with start-up and spin-off companies created in collaboration with the project. 

One of the principles of the SHIFT team has been been exploring how best to harness the concept of a circular economy. For example, they are looking into how waste products from the textile and food industries can be reused in these treatments.

Yet with complicated interactions at a microscale, and the need to prevent the body from rejecting foreign materials, such tissue engineering is a big challenge. 

‘The complexity is high because the nature of biology is not easy,’ said Motta. ‘We cannot change the language of the cells, but instead have to learn to speak the same language as them.’

But she firmly believes the nature-based rather than synthetic approach is the way to go and thinks treatments harnessing SHIFT’s methods could become available in the early 2030s. 

‘I believe in this approach,’ said Motta. ‘Bone designed by nature is the best bone we can have.’

Skin care

Another EU-funded project known as SkinTERM [Skin Tissue Engineering and Regenerative Medicine: From skin repair to regeneration], which runs for almost five years until mid-2025, is also looking at novel ways to get tissue to self-regenerate, focusing on skin. To treat burns and other surface wounds today, a thin layer of skin is sometimes grafted from another part of the body. This can cause the appearance of disfiguring scars and the patient’s mobility may be impacted when the tissue contracts as it heals. Current skin-grafting methods can also be painful.

The SkinTERM team are therefore investigating how inducing the healing process in the networks of cells surrounding a wound might enable skin to repair itself. 

‘We could do much better if we move towards regeneration,’ said Dr Willeke Daamen, who coordinates SkinTERM as a researcher in soft tissue regeneration at Radboud University in Nijmegen, the Netherlands. ‘The ultimate goal would be to get the same situation before and after being wounded.’

Researchers are studying a particular mammal – the spiny mouse – which has a remarkable ability to heal without scarring. It is able to self-repair damage to other tissues like the heart and spinal cord too. This is also true of early foetal skin.

The team are examining these systems to learn more about how they work and the processes occurring in the area around cells, known as the extracellular matrix. They hope to identify factors that might have a role in the regenerative process, and test how it might be induced in humans. 

Kick-start

‘We’ve been trying to learn from those systems on how to kick-start such processes,’ said Daamen. ‘We’ve made progress in what kinds of compounds seem at least in part to be responsible for a regenerative response.’

Many lines of research are being carried out among a new generation of multidisciplinary scientists being trained in this area, and a lot has already been achieved, said Daamen.

They have managed to create scaffolds using different components related to skin regeneration, such as the proteins collagen and elastin. They have also collected a vast amount of data on genes and proteins with potential roles in regeneration. Their role will be further tested by using them on scar-prone cells cultured on collagen scaffolds.

‘The mechanisms are complex,’ said Dr Bouke Boekema, a senior researcher at the Association of Dutch Burn Centres in Beverwijk, the Netherlands, and vice-coordinator of SkinTERM. 

‘If you find a mechanism, the idea is that maybe you can tune it so that you can stimulate it. But there’s not necessarily one magic bullet.’

By the end of the project next year, Boekema hopes the research could result in some medical biomaterial options to test for clinical use. ‘It would be nice if several prototypes were available for testing to see if they improve outcomes in patients.’

Research in this article was funded by the Marie Skłodowska-Curie Actions (MSCA). The views of the interviewees don’t necessarily reflect those of the European Commission. If you liked this article, please consider sharing it on social media.

Interesting. Over these last few months, I’ve been stumbling across more than my usual number of regenerative medicine stories.

Grow better organ-like tissues by using silkworms

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A June 6, 2024 news item on ScienceDaily describes a technique, which could lead to better organ-on-a-chip (OOC) systems,

Biomedical engineers at Duke University [North Carolina, US] have developed a silk-based, ultrathin membrane that can be used in organ-on-a-chip models to better mimic the natural environment of cells and tissues within the body. When used in a kidney organ-on-a-chip platform, the membrane helped tissues grow to recreate the functionality of both healthy and diseased kidneys.

By allowing the cells to grow closer together, this new membrane helps researchers to better control the growth and function of the key cells and tissues of any organ, enabling them to more accurately model a wide range of diseases and test therapeutics.

…

A June 6, 2024 Duke University news release (also on EurekAlert), which originated the news item, describes the OOC system and the problem these researchers are seeking to solve,

Often no larger than a USB flash drive, organ-on-a-chip (OOC) systems have revolutionized how researchers study the underlying biology of the human body, whether it’s creating dynamic models of tissue structures, studying organ functions or modeling diseases. These platforms are designed to stimulate cell growth and differentiation in a way that best mimics the organ of interest. Researchers can even populate these tools with human stem cells to generate patient-specific organ models for pre-clinical studies.

But as the technology has evolved, problems in the chip’s design have also emerged –– most notably with the materials used to create the membranes that form the support structure for the specialized cells to grow on. These membranes are typically composed of polymers that don’t degrade, creating a permanent barrier between cells and tissues. While the extracellular membranes in human organs are often less than one micron thick, these polymer membranes are anywhere from 30 to 50 microns, hindering communication between cells and limiting cell growth.

“We want to handle the tissues in these chips just like a pathologist would handle biopsy samples or even living tissues from a patient, but this wasn’t possible with the standard polymer membranes because the extra thickness prevented the cells from forming structures that more closely resemble tissues in the human body,” said Samira Musah, an assistant professor of biomedical engineering and medicine at Duke. “We thought, ‘Wouldn’t it be nice if we could get a protein-based material that mimics the structure of these natural membranes and is thin enough for us to slice and study?’”

This question led Musah and George (Xingrui) Mou, a PhD student in Musah’s lab and first author on the paper, to silk fibroin, a protein created by silkworms that can be electronically spun into a membrane. When examined under a microscope, silk fibroin looks like spaghetti or a Jackson Pollock painting. Made out of long, intertwining fibers, the porous material better mimics the structure of the extracellular matrix found in human organs, and it has previously been used to create scaffolds for purposes like wound healing.

“The silk fibroin allowed us to bring the membrane thickness down from 50 microns to five or fewer, which gets us an order of magnitude closer to what you’d see in a living organism,” explained Mao.

To test this new membrane, Musah and Mao applied the material to their kidney chip models. Made out of a clear plastic and roughly the size of a quarter, this OOC platform is meant to resemble a cross section of a human kidney––specifically the glomerular capillary wall, a key structure in the organ made from clusters of blood vessels that is responsible for filtering blood.

Once the membrane was in place, the team added human induced pluripotent stem cell derivatives into the chip. They observed that these cells were able to send signals across the ultrathin membrane, which helped the cells differentiate into glomerular cells, podocytes and vascular endothelial cells. The platform also triggered the development of endothelial fenestrations in the growing tissue, which are holes that allow for the passage of fluid between the cellular layers.

By the end of the test, these different kidney cell types had assembled into a glomerular capillary wall and could efficiently filter molecules by size.

“The new microfluidic chip system’s ability to simulate in vivo-like tissue-tissue interfaces and induce the formation of specialized cells, such as fenestrated endothelium and mature glomerular podocytes from stem cells, holds significant potential for advancing our understanding of human organ development, disease progression, and therapeutic development,” said Musah.

As they continue to optimize their model, Musah and colleagues are hoping to use this technology to better understand the mechanisms behind kidney disease. Despite affecting more than 15 percent of American adults, researchers lack effective models for the disease. Patients are also often not diagnosed until the kidneys have been substantially damaged, and they are often required to undergo dialysis or receive a kidney transplant.

“Using this platform to develop kidney disease models could help us discover new biomarkers of the disease,” said Mao. “This could also be used to help us screen for drug candidates for several kidney disease models. The possibilities are very exciting.”

“This technology has implications for all organ-on-a-chip models,” said Musah. “Our tissues are made up of membranes and interfaces, so you can imagine using this membrane to improve models of other organs, like the brain, liver, and lungs, or other disease states. That’s where the power of our platform really lies.”

This work was supported by a Whitehead Scholarship in Biomedical Research, Chair’s Research Award from the Department of Medicine at Duke University, MEDx Pilot Grant on Biomechanics in Injury or Injury Repair, Burroughs Wellcome Fund PDEP Career Transition Ad Hoc Award, Duke Incubation Fund from the Duke Innovation & Entrepreneurship Initiative, Genetech Research Award, a George M. O’Brien Kidney Center Pilot Grant (P30 DK081943), an NIH [National Institutes of Health] Director’s New Innovator Grant (DP2DK138544).

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

An Ultrathin Membrane Mediates Tissue-Specific Morphogenesis and Barrier Function in a Human Kidney Chip by Xingrui Mou, Jessica Shah, Yasmin Roye, Carolyn Du, Samira Musah. Science Advances. June 4, 2024 Vol 10, Issue 23 DOI: https://doi.org/10.1126/sciadv.adn2689

This paper is open access.

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.

…

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.