Category: 7. Science

In a breakthrough for regenerative medicine, a new study from IMDEA Materials Institute researchers has demonstrated the potential of 3D printed carbon microlattices as structurally tunable scaffolds for bone tissue engineering. Specifically, the scaffolds were fabricated using 3D printed polyethylene glycol diacrylate (PEGDA) structures that are transformed into pyrolytic carbon (PyC) through high-temperature treatment.

Their findings, published in Small Structures, open up promising avenues for the use of carbon-based materials in bone tissue engineering, a field long in search of biomaterials that combine mechanical robustness, biocompatibility, and tailored design with geometrical precision.

“This study presents the first comprehensive in vitro evaluation of 3D printed PyC scaffolds for bone regeneration. Our goal was to move beyond conventional scaffold materials and explore carbon as a fully architected, tunable platform for tissue engineering. While other forms of carbon like graphene or carbon nanotubes have shown promise in bone regeneration, they typically require embedding in polymers, which often mask their true potential,” said Dr. Monsur Islam from IMDEA Materials. “We were excited by the idea of using pure carbon, shaped entirely through 3D printing and pyrolysis, to create scaffolds with programmable mechanical and chemical properties. What’s truly remarkable is that these structures can guide cell behavior, promoting either proliferation or osteogenesis, without any surface coatings or bioactive additives. That’s what makes this work feel like a turning point for carbon in regenerative medicine.”

The team behind the publication, led by Dr. Islam, also includes IMDEA Materials researchers Wei Tang, Dr. Miguel Monclús, Dr. Mónica Echeverry Rendón, Prof. De-Yi Wang, and former IMDEA Materials researcher Dr. Jesús Ordoño.

Pyrolysis is a process in which organic materials are decomposed at high temperatures in the absence of oxygen.

In the study, carried out as part of the European Marie Skłodowska Curie Actions project 3D-CARBON, PEGDA, an organic photo-sensitive resin, was first used for UV-light-based resin 3D printing, where intricate 3D PEGDA structures were fabricated in a layer-by-layer photopolymerization process.

These structures were later subject to a high-temperature pyrolysis process, resulting in the formation of a carbon-based framework exhibiting enhanced mechanical, electrical, or thermal properties depending on the processing conditions.

Importantly, the original structures experienced a significant geometrical shrinkage (up to ~80%), while retaining the original geometry. This shrinkage enabled a higher printing resolution compared to the UV 3D printing process, leading to the fabrication of pore geometries similar to native bone.

Researchers also demonstrated how varying the pyrolysis temperature from 500 to 900 °C effectively tuned both the physical and biological properties of the resulting carbon microlattices.

At higher temperatures, the carbon becomes more conductive and mechanically robust, with elasticity and hardness values approaching those of natural bone, making them particularly promising for clinical applications in bone repair.

Interestingly, the study shows that PyC scaffolds created at lower pyrolysis temperatures retain more oxygen-containing surface groups, leading to greater metabolic activity and enhanced cell proliferation. This suggests that adjusting the pyrolysis parameters offers a powerful tool to direct cellular behavior.

Unlike many existing scaffold materials, such as polymers that lack strength or ceramics that are extremely challenging to process to the geometrical scale of native bone, these PyC microlattices offer a rare combination of processability, biocompatibility, mechanical resilience, and surface tunability.

In addition, their potential compatibility with MRI-based monitoring presents a notable advantage over metal-based implants.

Miguel Claro is a professional photographer, author and science communicator based in Lisbon, Portugal, who creates spectacular images of the night sky. As a European Southern Observatory Photo Ambassador and member of The World At Night and the official astrophotographer of the Dark Sky Alqueva Reserve, he specializes in astronomical “Skyscapes” that connect both Earth and the night sky.

Last year, at the end of summer, we had a vibrant comet visiting the northern skies, so I took this opportunity to capture a few images over the course of several nights.

Cells called astrocytes are about as abundant in the brain as neurons, but scientists have spent much less time figuring out how they contribute to brain functions. A novel study by MIT researchers at The Picower Institute for Learning and Memory shows that one function appears to be maintaining the chemical conditions necessary for groups of neurons to team up to encode information.

Specifically, the neuroscientists showed that when they knocked out the ability of astrocytes in the visual cortex of mice to produce a protein called “GABA transporter 3 (Gat3),” neurons there became less able as a group to represent information about the movies lab mice were seeing. GABA is a common inhibitory neurotransmitter that sharpens neural activity and astrocytes uniquely use Gat3 to regulate the ambient level of GABA in their area. In the study in eLife, knocking out Gat3 in the visual cortex left neurons stewing in a soup of excess GABA that only produced subtle effects on individual neurons, but nevertheless added up to a significant impairment on their efforts as an ensemble responsible for visual function.

Even if the changes at the level of a single neuron representing a visual stimulus do not change significantly, if a hundred neurons have some small changes, that could add up at the population level to a measurable, significant change.”

Mriganka Sur, Senior Author, Paul and Lilah Newton Professor in The Picower Institute and MIT’s Department of Brain and Cognitive Sciences (BCS)

Notably, the authors wrote in eLife, this is the first study in live mice of Gat3 at scales spanning individual cells and functional ensembles of hundreds of them.

To make the discovery, BCS graduate student Jiho Park used a novel implementation of CRISPR/Cas9 gene editing to knock out Gat3 combined with statistical and computational analyses of neural activity at the population level, Sur said.

Gat out

As neuroscientists have studied the brain’s visual system over many decades, neurons have claimed most of their attention because they are electrically active and more easily targeted genetically, Sur said. Technology for tracking astrocyte activity and for manipulating their function hasn’t developed as quickly. But in 2019, the National Institutes of Health gave Sur a grant to develop better tools for studying astrocytes. That funding helped the lab create the variant of CRISPR/Cas9 they call MRCUTS that enabled the new study. The tool allowed them to use just one viral vector to target the gene that encodes Gat3 for multiple cuts. That multiplexed attack decisively and precisely knocked it out in visual cortex astrocytes.

Once Park knocked out Gat3, she could see the effects of its absence by visually tracking the calcium activity of neurons, a proxy for their electrical activity. The consequences were more subtle than the team expected. Awash in GABA, neurons fired less robustly and less reliably. When the mice were watching only a gray screen, instead of movies, the neurons would spontaneously activate less often, too.

But to the researchers’ surprise, when Gat3 was gone the neurons individually still did their jobs. Cells that in the presence of Gat3 were responsive to different features of the images the mice were seeing, such as the orientation of lines, remained responsive even after Gat3 was knocked out. Though ambient levels of GABA were higher, pairs of neurons still shared GABA through their direct connections, or “synapses,” as before, meaning their direct dialogue with each other didn’t change.

“We were expecting to see changes in orientation tuning among other things, but we didn’t see that,” Park said. “That’s why we looked into deeper levels of analysis to see if there’s any difference.”

Disrupted teamwork

That deeper analysis occurred at the level of broader neural ensembles, where Park used several statistical and computational methods to analyze how the collective information encoding by hundreds of neurons changed when Gat3 was knocked out.

Using a statistical method called a “Generalized Linear Model” to analyze patterns of activity across the ensemble, Park discovered that when Gat3 was knocked out, the activity of neurons became less predictive of the activity of others in the group compared to when Gat3 was present. This indicated that while individual neurons might still be doing what they were supposed to, their coordination was impaired. Meanwhile using a “Support Vector Machine”-based decoder to discern the information that ensembles were representing, she found that when Gat3 was present the decoder could improve its assessment as more neurons were added to its sample. But when Gat3 was knocked out, the decoder could no longer ascertain the represented information even as its sample size increased.

“The decoding deficits following Gat3 ablation provide evidence that astrocytic regulation of ambient GABA is essential for organizing the coordinated neuronal activity patterns necessary for efficient information encoding in visual cortical networks,” the authors wrote in eLife.

Clinical cases

The finding that a lack of Gat3 disrupts neural coordination at the population level might help explain clinical observations that Gat3 reduction in the thalamus increases seizure risk, Gat3 increase in the striatum contribute to repetitive behaviors, and Gat3 reduction in the globus pallidus impairs motor coordination, Park said.

“Because our study is the first to look at Gat3 effects on a population level, it might help tie that back to some of the behavioral phenotypes people have been seeing,” Park said. But more research is needed, Sur noted, because there are other Gat proteins, such as Gat1, that the brain might use to compensate.

In addition to Park and Sur, the paper’s other authors are Grayson Sipe, Xin Tang, Prachi Ojha, Giselle Fernandes, Yi Ning Leow, Caroline Zhang, Yuma Osako, Arundhati Natesan, Gabrielle Drummond and Rudolf Jaenisch.

The National Institutes of Health, a MURI Grant, The Simons Foundation Autism Research Initiative, the Freedom Together Foundation and The Picower Institute for Learning and Memory provided funding for the study.

Each year, more money is spent in the U.S. on musculoskeletal pain than on heart disease and diabetes combined. Exercise physiologist Keith Baar, a professor of Neurobiology, Physiology and Behavior and Physiology and Membrane Biology, is working to change that.

“My lab is concerned with helping people move well throughout their lives,” said Baar. “We’re using an understanding of basic science principles to change a lot of how physical therapy is done. If we can help people move better, we can decrease diseases like diabetes and heart disease. In fact, if you rupture your ACL, you’re 50% more likely to have a heart attack than somebody who hasn’t.”

From basic research to the clinic, gym, and track

Baar’s lab uses a combination of methods to understand how muscles, tendons, and ligaments respond to exercise and nutrition, including molecular and genetic studies, rat models, and human studies.

Baar, who joined UC Davis in 2009, first began studying exercise physiology to understand his own limitations as an athlete.

“I was a very good athlete, and I wanted to know why I wasn’t a great athlete,” said Baar. “A lot of people enter my field to try and figure out what’s holding them back from performing at the world-class level.”

And though he often works with elite athletes — including professional rock climbers, the Denver Broncos, USA Track and Field, and the Chelsea football club — Baar’s work applies to everyone.

“In the last 10 years, my lab has been shifting towards studying tendons and ligaments, because more than 70% of us will suffer a significant tendon injury during our life that will limit our ability to do the things we love,” said Baar.

Exercising smarter, not harder

Baar’s lab has shown that static, controlled forms of exercise, such as planks or wall sits, can be just as powerful as high impact exercises like running. Specifically, they’ve shown that holding static positions for 10 to 30 seconds at a time — which is known as isometric exercise — can help people recover completely from tendon and ligament injuries, which was previously thought to be impossible. During these longer holds, your tendons begin to relax, which means your muscles have to work harder to hold you in place. At the molecular level, this type of exercise stimulates muscle, tendon, and ligament production and alters how genes are switched on or off within the tissues.

“Isometric exercises can fix tendons and ligaments, even though people thought for years that you couldn’t fix these tissues,” said Baar. “We’ve shown that two 15-minute isometric exercise sessions – one in the morning and one in the evening – can actually yield greater benefits than a single 30-minute standard PT session,” said Baar.

These exercises are also a good entry point for people who are older, new to exercise, or who have an underlying metabolic condition. “If grandma wants to maintain the daily routine she’s always had, these are the things that she can do to get stronger and keep her activity level the same,” said Baar.

Lab-grown ligaments

To better understand these tissues, Baar and his team developed a way to grow them from the remnants of human ACL reconstructive surgeries performed at the UC Davis Medical Center.

“From that little piece of ACL, we can make about a thousand engineered ligaments,” said Baar. “And from there, we can exercise them, we can give them different nutrition, we can give them drugs, we can look at their gene expression and which proteins they make — we basically have total control over these little engineered ligaments.”

Using these lab-grown ligaments, Baar’s team showed that tendons and ligaments stop responding to exercise after only about ten minutes.

“Your bones, tendons, ligaments, and cartilage stop getting the signal to get stronger after about five or ten minutes of exercise,” said Baar. “After that, they accumulate more wear and tear, but get no further signal to get better. We’ve used this knowledge to inform our recommendations for elite athletes who’ve experienced injury. Instead of removing training, we add a small amount of training that’s optimized for the connective tissues, and that keeps them healthy and allows them to train harder for longer.”

Baar’s work has been funded by the National Institutes of Health as well as donations from the Clara Wu and Joe Tsai Foundation and Human Performance Alliance. His research has utilized several UC Davis research core facilities, including UC Davis Genome Center and the Bioinformatics Core Facility. 

In a scientific first, researchers from Vanderbilt University and the University of California, San Diego, have generated a high-resolution metabolic “map” of how cells orchestrate glucose processing, revealing a hidden world where organelles and molecular complexes collaborate when responding to a rush of nutrients. This new study, published in Nature Communications, has redefined how glucose metabolism is visualized at the single-cell level. The pioneering work provides both a new method and insights into an organizational and molecular framework that can be used to study how metabolic processes are disrupted in diseases like diabetes, obesity, and cancer, as well as in aging and neurodegeneration.

“This is a new field-we are at the forefront by integrating multiple microscopy modes into sophisticated pipelines to measure the fate of glucose atoms, from whole animals to organelles, and to show the underlying subcellular architecture associated with these processes in cells,” Rafael Arrojo e Drigo said. Arrojo e Drigo is an assistant professor of molecular physiology and biophysics and the corresponding author of the study. “We expect that this advance will propel a new program that exploits these advanced investigational strategies to study and better understand how nutrient metabolism is organized within the highly structured domains of cells and tissues, which allows for the precise regulation of organ function in the context of whole-animal physiology.”

To date, what scientists know about how cells process nutrients like glucose has been derived from bulk metabolomics. Using metabolomics, researchers can analyze an entire set of small molecules within a biological sample, such as a tissue, but it’s done without consideration of the specific spatial or subcellular contexts in which they occur.

These bulk strategies do not reveal the spatial characteristics of cell metabolism at the single-cell level or how these aspects relate to the location of cells and organelles within the complexity of the tissue they reside within.”

Rafael Arrojo e Drigo, assistant professor of molecular physiology and biophysics and corresponding author of the study

This gap in the field’s understanding drove a multidisciplinary team from Vanderbilt, the Vanderbilt University Medical Center, and UCSD to combine stable isotope tracing, multi-scale microscopy, and AI-powered image analysis to map glucose metabolites at animal, tissue, cellular, and organellar scales. The Vanderbilt team was led by co-first authors Christopher Acree and Aliyah Habashy from the Arrojo e Drigo lab and included scientists from the Vanderbilt Mouse Metabolic Phenotyping Center, the Mass Spectrometry Research Center, the Department of Cell and Developmental Biology, and the VUMC Department of Surgery. Researchers from Mark Ellisman’s group at the National Center for Microscopy and Imaging Research at UCSD rounded out the collaboration.

Together, they determined the spatial organization of glucose metabolites, from inside whole animals to within liver cells and even in individual mitochondria. Using isotopically labeled glucose infusions in live mice, the researchers mapped how glucose-derived carbons were incorporated into glycogen, lipid droplets, and other cellular components over time.

Among the major discoveries of this study, the team uncovered a previously unrecognized structural and functional interaction between lipid droplets and glycogen synthesis. In addition, the researchers mapped how contacts between mitochondria and the endoplasmic reticulum-two key organelles involved in energy production and nutrient sensing-shift dynamically in response to changes in blood glucose levels. These mitochondria-ER contacts form part of a broader organelle network that coordinates metabolic responses within the cell. By charting the timeline of these interactions, the study offers new insights into how organelles reorganize to adapt to different metabolic states, shedding light on fundamental mechanisms of glucose metabolism and cellular energy balance.

This breakthrough was made possible by Vanderbilt’s characteristic interdisciplinary environment and the multi-scale, multi-modal imaging thrust of the NCMIR, an alliance that brought together experts in stable isotope tracing, in vivo animal metabolism, mass spectrometry imaging, AI, and computational modeling, Arrojo e Drigo said. Looking ahead, the team hopes to understand how the spatial organization of nutrients inside cells contributes to metabolic health and disease.

In living organisms today, complex molecules like RNA and DNA are constructed with the help of enzymes. So how did these molecules form before life (and enzymes) existed? Why did some molecules end up as the building blocks of life and not others? A new study by Scripps Research scientists helps answer these longstanding questions.

The results, published in the chemistry journal Angewandte Chemie on June 27, 2025, show how ribose may have become the sugar of choice for RNA development. They found that ribose binds to phosphate-another molecular component of RNA-more quickly and effectively than other sugar molecules. This feature could have helped select ribose for inclusion in the molecules of life.

This gives credence to the idea that this type of prebiotic chemistry could have produced the building blocks of RNA, which then could have led to entities which exhibit lifelike properties.”

Ramanarayanan Krishnamurthy, corresponding author, professor of chemistry at Scripps Research

Nucleotides, the building blocks of RNA and DNA, consist of a five-carbon sugar molecule (ribose or deoxyribose) that is bound to a phosphate group and a nitrogen-based base (the part of the molecule that encodes information, e.g., A, C, G or U). Krishnamurthy’s research aims to understand how these complex molecules could have arisen on primordial Earth. Specifically, this study focused on phosphorylation, the step within nucleotide-building where ribose connects to the phosphate group.

“Phosphorylation is one of the basic chemistries of life; it’s essential for structure, function and metabolism,” says Krishnamurthy. “We wanted to know, could phosphorylation also play a fundamental role in the primordial process that got all of these things started?”

From previous work, the team knew that ribose could become phosphorylated when combined with a phosphate-donating molecule called diamidophosphate (DAP). In this study, they wanted to know whether other, similar sugars could also undergo this reaction, or whether there is something special about ribose.

To test this, the researchers used controlled chemical reactions to investigate how quickly and effectively ribose is phosphorylated by DAP compared to three other sugar molecules with the same chemical makeup but a different shape (arabinose, lyxose and xylose). Then, they used an analytical technique called nuclear magnetic resonance (NMR) spectroscopy to characterize the molecules produced by each reaction.

They showed that although DAP was able to phosphorylate all four sugars, it phosphorylated ribose at a much faster rate. Additionally, the reaction with ribose resulted exclusively in ring-shaped structures with five corners (e.g., 5-member rings), whereas the other sugars formed a combination of 5- and 6-member rings.

“This really showed us that there is a difference between ribose and the three other sugars,” says Krishnamurthy. “Ribose not only reacts faster than the other sugars, it’s also more selective for the five-member ring form, which happens to be the form that we see in RNA and DNA today.”

When they added DAP to a solution containing equal amounts of the four different sugars, it preferentially phosphorylated ribose. And whereas the other three sugars got “stuck” at an intermediate point in the reaction, a large proportion of the ribose molecules were converted into a form that could likely react with a nuclear base to form a nucleotide.

“What we got was a 2-in-1: We showed that ribose is selectively phosphorylated from a mixture of sugars, and we also showed that this selective process produces a molecule with a form that is conducive for making RNA,” says Krishnamurthy. “That was a bonus. We did not anticipate that the reaction would pause at the stage advantageous for producing nucleotides.”

The researchers caution that, even if these reactions can all occur abiotically, it doesn’t mean that they are the reactions that necessarily resulted in life.

“Studying these types of chemistries helps us understand what sort of processes might have led to the molecules that constitute life today, but we are not making the claim that this selection is what led to RNA and DNA, because that’s quite a leap,” says Krishnamurthy. “There are a lot of other things that need to happen before you get to RNA, but this is a good start.”

In future research, the team plans to test whether this chemical reaction can occur inside primitive cellular structures called “protocells.”

“The next question is, can ribose be selectively enriched within a protocell, and can it further react to make nucleotides within a protocell?” says Krishnamurthy. “If we can make that happen, it might produce enough tension to force the protocell to grow and divide – which is exactly what underpins how we grow.”

In addition to Krishnamurthy, the study “Selection of Ribofuranose-Isomer Among Pentoses by Phosphorylation with Diamidophosphate” was co-authored by Harold A. Cruz of Scripps Research.

The work was supported by the NASA Astrobiology Exobiology grant (80NSSC22K0509).

Space changes people in surprising ways. One of the most puzzling shifts that astronauts have experience on long missions is blurry vision.

Many found themselves needing stronger reading glasses the longer they stayed aboard the International Space Station. Researchers began to investigate and found a pattern. The astronauts’ eyes were changing shape.

Optic discs – where the optic nerve connects to the eye – were swelling. Eventually, these symptoms were grouped under one name: Space-Associated Neuro-Ocular Syndrome, or SANS.

Microgravity messes with astronaut vision

Scientists began digging deeper into what causes these eye problems. The key issue appears to be the effect of microgravity.

In space, fluids in the body shift upward toward the head. Blood and cerebrospinal fluid don’t settle as they do on Earth. This headward fluid shift is now thought to be one of the main reasons behind SANS.

To test how this works, researchers launched the Thigh Cuff investigation. The study explores whether wearing snug cuffs around the upper thighs can redirect fluid away from the head.

If effective, these cuffs could offer a simple, noninvasive way to prevent vision problems in space. And not just in orbit – this approach could also help patients on Earth who experience fluid buildup due to illness or extended bed rest.

Eye data from 300 astronauts

From 2015 through 2020, a project called Fluid Shifts documented how blood drains from the brain differently in space.

Around the same time, the Vision Impairment and Intracranial Pressure (VIIP) study tested whether increased brain fluid pressure played a role in SANS.

To get answers, scientists used clinical eye exams – both with and without dilation – as well as imaging of the retina, optic nerve, and surrounding blood vessels.

Noninvasive scans helped measure the thickness of different eye structures. They also collected MRI data and surveyed nearly 300 astronauts about how their vision changed during missions.

Understanding astronaut vision issues

In a paper published from this research, scientists noted that these tools have improved the understanding of SANS. They also discussed a new idea: a head-mounted virtual reality device that could someday assess SANS in real time using multiple types of data.

Another research group looked into the optic nerve sheath. They discovered that measuring its diameter might be a reliable way to track vision changes during space travel.

The team also urged fellow scientists to standardize how these tests are done to make future studies easier to compare and repeat.

One astronaut’s unusual vision case

One study focused on a single astronaut who experienced more severe symptoms than most after a six-month mission.

In this case, the symptoms began to improve mid-mission – possibly due to two factors: vitamin B supplements and a drop in cabin carbon dioxide levels after some crew members left the station.

“While a single case does not allow researchers to determine cause and effect, the magnitude of the improvements suggest this individual may be more affected by environmental conditions,” said the researchers.

They noted that this may have been the first attempt to mitigate SANS with inflight B vitamin supplementation.

Is eye tissue softer in space?

Another study, SANSORI, which was led by the Canadian Space Agency, used Optical Coherence Tomography to explore whether softer eye tissue might be part of the problem. On Earth, a loss of tissue stiffness is linked to aging and diseases like glaucoma or myopia.

Scientists found that long stays in space affected the stiffness of tissues around the eyeball. That change might help explain why eyes start to lose their shape during spaceflight.

The results could also help doctors better understand vision problems in older adults here on Earth.

Genes, mice, and artificial gravity

Meanwhile, researchers in Japan ran the MHU-8 experiment. They looked at how space travel affects gene expression in mice.

After the mice returned to Earth, the team found changes in their optic nerves and retinas.

Interestingly, the experts also tested whether artificial gravity might reduce these changes – and it did. This raises the possibility of using rotating habitats or other tools to simulate gravity during future missions.

Protecting vision in space

SANS is still being studied, but every experiment brings scientists closer to understanding how space affects the human body – and how to protect it.

The hope is that one day, astronauts headed to the Moon or Mars won’t have to worry about vision loss. And the same discoveries may help people on Earth too.

Information for this article was obtained from a NASA press release.

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Researchers in Japan have developed a lactate-based bioplastic that can biodegrade in deep-ocean environments, losing over 80% of its mass after 13 months underwater.

Their research, published in Polymer Degradation and Stability, highlights the potential of poly(D-lactate-co-3-hydroxybutyrate) (LAHB) as an alternative to conventional plastics such as polylactide (PLA), which remain intact under deep sea conditions.

Marine plastic waste continues to accumulate in aquatic ecosystems. The Organisation for Economic Co-operation and Development (OECD) reports that around 353 million metric tons of plastic waste were produced globally in 2019, with nearly 1.7 million metric tons flowing directly into aquatic ecosystems. Some of this debris is trapped in large circulating ocean currents, or gyres, forming persistent floating waste patches.

Investigating degradation on the sea floor

To tackle the issue of plastics in marine environments, research teams around the globe are looking to develop bioplastic alternatives to PLA and other conventional plastics which will breakdown more readily to prevent the build-up of plastic debris.

To test the biodegradability of LAHB in real-world conditions, the researchers submerged plastic samples near Hatsushima Island, Japan, at a depth of 855 meters. The site features low temperatures (3.6 °C), high salinity, limited oxygen and minimal nutrients, all of which slow microbial activity.

The team deployed two types of LAHB films with different lactic acid content – one containing 6% lactic acid (P6LAHB) and another containing 13% (P13LAHB) – alongside a PLA film to act as a control. After 13 months, the P13LAHB sample had degraded by more than 82%, with the P6LAHB showing a similar decline. In contrast, the PLA film exhibited no measurable change in mass or surface characteristics.

“Our study demonstrates for the first time that LAHB, a microbial lactate-based polyester, undergoes active biodegradation and complete mineralization even on the deep-sea floor, where conventional PLA remains completely non-degradable,” commented study author Seiichi Taguchi, a professor at the Institute for Aqua Regeneration, Shinshu University, Japan.

Scanning electron microscopy revealed cracks on the LAHB film surfaces and the presence of microbial biofilms composed of oval- and rod-shaped cells. In contrast, the PLA film remained smooth and biofilm-free.

Enzymes drive stepwise plastic breakdown

To learn more about how the bioplastic breaks down, further analysis focused on the plastisphere – a term given to the microbial ecosystem that forms on plastic surfaces, especially in aquatic environments.

Dominant organisms included genera from the Gammaproteobacteria class, such as Colwellia, Pseudoteredinibacter, Agarilytica, and UBA7957. These microbes secrete extracellular enzymes – specifically poly(3-hydroxybutyrate) depolymerases – that initiate plastic degradation by cleaving long polymer chains into shorter trimers and dimers.

Certain species, such as UBA7959, also produce oligomer hydrolases (like PhaZ2) that further break down dimers and trimers into their monomeric forms.

Additional bacterial groups, including Alphaproteobacteria and Desulfobacterota, continue the breakdown process, metabolizing the resulting monomers. Ultimately, these bacteria convert LAHB into carbon dioxide, water and other environmentally benign compounds.

A potential step toward marine-safe plastics

The study is the first to confirm that LAHB can degrade under high-pressure, low-temperature marine conditions where conventional biodegradable plastics typically fail. The findings provide a data-driven basis for exploring LAHB as a safer material in efforts to reduce marine plastic waste.

“This research addresses one of the most critical limitations of current bioplastics—their lack of biodegradability in marine environments. By showing that LAHB can decompose and mineralize even in deep-sea conditions, the study provides a pathway for safer alternatives to conventional plastics and supports the transition to a circular bioeconomy,” said Taguchi.

Reference: Ishii S, Koh S, Suzuki M, Kasuya K, Taguchi S. Unveiling deep-sea biodegradation of microbially produced lactate-based polyester (LAHB) via plastisphere metagenomics and metatranscriptomics. Polym Degrad Stab. 2025;240:111527. doi: 10.1016/j.polymdegradstab.2025.111527

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Newswise — A team led by the Trottier Institute for Research on Exoplanets (IREx) at the Université de Montréal has achieved the most precise study to date of the L 98-59 planetary system, and confirmed the existence of a fifth planet in the star’s habitable zone, where conditions could allow liquid water to exist.

Volcanic planets, a sub-Earth, and a water world

L 98-59, a small red dwarf located just 35 light-years from Earth, hosts three small transiting exoplanets discovered in 2019, thanks to NASA’s TESS space telescope, and a fourth planet revealed through radial velocity measurements with the European Southern Observatory’s ESPRESSO spectrograph. All four planets orbit their parent star in a compact orbital configuration, all at distances five times closer than Mercury is to the Sun.

By carefully reanalyzing a rich set of observations from ground-based and space-based telescopes, a team led by Université de Montréal and Trottier Institute for Research on Exoplanets (IREx) researcher Charles Cadieux has determined the planets’ sizes and masses with unprecedented precision.

“These new results paint the most complete picture we’ve ever had of the fascinating L 98-59 system,” said Cadieux. “It’s a powerful demonstration of what we can achieve by combining data from space telescopes and high-precision instruments on Earth, and it gives us key targets for future atmospheric studies with the James Webb Space Telescope [JWST].”

All planets in the system have masses and sizes compatible with the terrestrial regime. The innermost planet, L 98-59 b, is only 84% of Earth’s size and about half its mass, making it one of the rare sub-Earths known with well-measured parameters.

The two inner planets may experience extreme volcanic activity due to tidal heating, similar to Jupiter’s volcanic Moon, Io, in the Solar System. Meanwhile, the third, unusually low in density, may be a “water world,” a planet enriched in water unlike anything in our Solar System.

The refined measurements reveal nearly perfectly circular orbits for the inner planets, a favourable configuration for future atmospheric detections.

“With its diversity of rocky worlds and range of planetary compositions, L 98-59 offers a unique laboratory to address some of the field’s most pressing questions: What are super-Earths and sub-Neptunes made of? Do planets form differently around small stars? Can rocky planets around red dwarfs retain atmospheres over time?” adds René Doyon, co-author of the study, who is a professor at UdeM and the Director of IREx.

A fifth planet in the habitable zone

One of the key breakthroughs of this study is the confirmation of a fifth planet in the L 98-59 system. This planet, designated L 98-59 f, does not transit its host star — meaning it doesn’t pass directly between us and the star — but its presence was revealed through subtle variations in the star’s motion, detected using radial velocity measurements from HARPS (High Accuracy Radial velocity Planet Searcher) and ESPRESSO data.

L 98-59 f receives about the same amount of stellar energy as Earth does from the Sun, placing it firmly within the temperate, or habitable zone, a region where water could remain in liquid form.

“Finding a temperate planet in such a compact system makes this discovery particularly exciting,” said Cadieux. “It highlights the remarkable diversity of exoplanetary systems and strengthens the case for studying potentially habitable worlds around low-mass stars.”

Unlocking new insights with existing observations

Rather than requesting new telescope time, the team made these discoveries by relying on a rich archive of data from NASA’s TESS space telescope, ESO’s HARPS and ESPRESSO spectrographs in Chile, and the JWST.

They employed the novel line-by-line radial velocity analysis technique introduced by IREx researchers in 2022 to improve the precision of the data significantly. By combining it with a new differential temperature indicator also developed by the team, they were able to precisely identify and remove the stellar activity signal from the data, revealing the planetary signal in unprecedented detail.

By combining these enhanced measurements with analysis of transits seen by JWST, the team doubled the precision of mass and radius estimates for the known planets.

“We developed these techniques to unlock this kind of hidden potential in archival data,” adds Étienne Artigau, co-author of the study and researcher at UdeM. “It also highlights how improving analysis tools allow us to improve upon previous discoveries with data that is just waiting to be revisited.”

Next stop: Webb

These results confirm L 98-59 as one of the most compelling nearby systems for exploring the diversity of rocky planets, and, eventually, searching for signs of life.

Its proximity, the small size of its star, and the range of planetary compositions and orbits make it an ideal candidate for atmospheric follow-up with the JWST, which the IREx team has already started.

“With these new results, L 98-59 joins the select group of nearby, compact planetary systems that we hope to understand in greater detail over the coming years,” says Alexandrine L’Heureux, co-author of the study and Ph.D. student at UdeM. “It’s exciting to see it stand alongside systems like TRAPPIST-1 in our quest to unlock the nature and formation of small planets orbiting red dwarf stars.”