. Scientific Frontline

Thursday, April 4, 2024

Airy cellulose from a 3D printer

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

Ultra-light, thermally insulating and biodegradable: Cellulose-based aerogels are versatile. Empa researchers have succeeded in 3D printing the natural material into complex shapes that could one day serve as precision insulation in microelectronics or as personalized medical implants.

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

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

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

Cystic fibrosis: why infections persist despite therapy

The anchor points present on the surface of the airways in cystic fibrosis (left image, in red) decrease when the balance between the two cell signaling pathways is restored (right image).
Image Credit: Marc Chanson et al, 2024

Cystic fibrosis is a genetic disease that causes serious and sometimes fatal respiratory and digestive disorders. A new treatment, available since 2020, improves lung function and quality of life. However, it does not always eradicate the bacteria responsible for respiratory infections. By studying 3D models of human lung cells, scientists at the University of Geneva (UNIGE) discovered that this drug does not prevent the development on the surface of the respiratory tract of ''docking stations'' to which bacteria attach themselves to infect the body. These docking stations result from a disruption in the signals involved in cell development in the respiratory system. By combining the current treatment with other molecules, it may be possible to restore cell balance and thus better prevent bacterial infections. These results are published in the American Journal of Respiratory Cell and Molecular Biology.

Cystic fibrosis is the most common genetic disease. Each year, it affects one in every 3,300 newborns in Switzerland. Mutations in the gene responsible for the CFTR protein cause the secretion of excessively thick mucus, which obstructs the airways. Although a triple therapy, available in Switzerland since 2020, has improved the quality of life of people with cystic fibrosis, it is not suitable for all those affected and does not always prove effective.

New sunflower family tree reveals multiple origins of flower symmetry

A new sunflower family tree reveals that flower symmetry evolved multiple times independently. Chrysanthemum lavandulifolium, on the upper left, and Artemisia annua, upper right, are closely related species from the same tribe; the former has bilaterally symmetric flowers — the rays — and the latter does not. Rudbeckia hirta, lower left, from the sunflower tribe has bilaterally symmetric flowers, and Eupatorium chinense, lower right, from the Eupatorieae tribe does not; these two tribes are closely related groups. A sunflower, center, shows flowers with bilateral symmetry — the large petal-like flowers in the outer row — and without bilateral symmetry — the small flowers in the inner rows.
Photo Credits: Guojin Zhang, Ma laboratory / Pennsylvania State University
(CC BY-NC-ND 4.0 DEED)

The sunflower family tree revealed that flower symmetry evolved multiple times independently, a process called convergent evolution, among the members of this large plant family, according to a new analysis. The research team, led by a Penn State biologist, resolved more of the finer branches of the family tree, providing insight into how the sunflower family — which includes asters, daisies and food crops like lettuce and artichoke — evolved.

A paper describing the analysis and findings, which researchers said may help identify useful traits to selectively breed plants with more desirable characteristics is available online and will be published in an upcoming print edition of the journal Plant Communications.

“Convergent evolution describes the independent evolution of what appears to be the same trait in different species, like wings in birds and bats,” said Hong Ma, Huck Chair in Plant Reproductive Development and Evolution, professor of biology in the Eberly College of Science at Penn State and the leader of the research team. “This can make it difficult to determine how closely related two species are by comparing their traits, so having a detailed family tree based on DNA sequence is crucial to understanding how and when these traits evolved.”

Scientists discover potential treatment approaches for polycystic kidney disease

cientists would like to know how cysts form in polycystic kidney disease (PKD). Here, they compared two 3-D mini-kidney models. On the left, a model shows a mini kidney with a gene mutation that causes cysts to form. On the right, researchers used gene editing to correct a gene mutation, preventing the development of cysts.
Image Credit: Vishy, et al., Cell Stem Cell 2024

Researchers have shown that dangerous cysts, which form over time in polycystic kidney disease (PKD), can be prevented by a single normal copy of a defective gene. This means the potential exists that scientists could one day tailor a gene therapy to treat the disease. They also discovered that a type of drug, known as a glycoside, can sidestep the effects of the defective gene in PKD. The discoveries could set the stage for new therapeutic approaches to treating PKD, which affects millions worldwide. The study, partially funded by the National Institutes of Health (NIH), is published in Cell Stem Cell.

Scientists used gene editing and 3-D human cell models known as organoids to study the genetics of PKD, which is a life-threatening, inherited kidney disorder in which a gene defect causes microscopic tubes in the kidneys to expand like water balloons, forming cysts over decades. The cysts can crowd out healthy tissue, leading to kidney function problems and kidney failure. Most people with PKD are born with one healthy gene copy and one defective gene copy in their cells.

“Human PKD has been so difficult to study because cysts take years and decades to form,” said senior study author Benjamin Freedman, Ph.D., at the University of Washington, Seattle. “This new platform finally gives us a model to study the genetics of the disease and hopefully start to provide answers to the millions affected by this disease.”

The Rotisserie-Inspired Device That Could Revolutionize Cancer Surgery

The Zavaleta Lab’S Raman Rotisserie Device Creates a Map of the Surface of a Resected Tumor to Aid Surgeons in the Operating Room.
Photo Credit: Alex Czaja

Like many Texans, Cristina Zavaleta grew up enjoying the culinary delights of the state’s famous smokehouse BBQs. She couldn’t have imagined that those humble rotisseries of her childhood would one day inspire a game-changing device for the operating room that could help surgeons prevent tumor recurrence.

On a team excursion to Disneyland, the WiSE Gabilan Assistant Professor of Biomedical Engineering and her students were reminded of rotisseries when they encountered a food vendor at the Star Wars-themed land, Galaxy’s Edge. It was a lightbulb moment. The rotisserie configuration was a perfect way of intricately scanning excised tumors, with the help of the Zaveleta Lab’s unique nanoparticles, to light up where the cancerous tissue may not have been entirely removed from the patient. Surgeons could then be guided to precisely remove the remaining tumor, all while the patient is still under anesthesia. The result would reduce the need for traumatic repeat surgeries and potential cancer recurrence and metastasis.

Zavaleta and her team built the device, which they dubbed the Raman Rotisserie. It physically rotates a tumor specimen and works in conjunction with an imaging technique known as Raman spectroscopy, which scans the surface of the excised tumor. Their research, which aims to improve the success rate of breast cancer lumpectomies, has now been published in NPJ Imaging.

Feeding the lonely brain

Study finds that lonely women experienced increased activation in regions of the brain associated with food cravings
Photo Credit: Ryanwar Hanif

A new UCLA Health study has found that women who perceive themselves to be lonely exhibited activity in regions of the brain associated with cravings and motivation towards eating especially when shown pictures of high calorie foods such as sugary foods. The same group of women also had unhealthy eating behaviors and poor mental health.

Arpana Gupta, Ph.D., a researcher and co-director of the UCLA Goodman-Luskin Microbiome Center, wanted to research the negative impacts of loneliness, especially as people continue to be working remotely after the COVID-19 pandemic, and how the brain interplays with social isolation, eating habits, and mental health. While it is established that obesity is linked to depression and anxiety, and that binge eating is understood to be a coping mechanism against loneliness, Gupta wanted to observe the brain pathways associated with these feelings and behaviors.

“Researching how the brain processes loneliness and how this is related to obesity and health outcomes hasn't been done,” said Gupta, senior author of the paper, which is published in JAMA Network Open

The researchers surveyed 93 women about their support system and their feelings of loneliness and isolation, then separated them into two groups: those who scored high on the perceived social isolation scale, and those who scored low. The researchers found that women who had higher levels of social isolation tended to have higher fat mass, lower diet quality, greater cravings, reward-based eating, and uncontrolled eating, and increased levels of anxiety and depression.

Vaping additives harm a vital membrane in the lungs, according to new Concordia research

Panagiota Taktikakis (left) and Christine DeWolf: “Understanding the impact of vaping additives on lung surfactant is vital, particularly for younger generations who are more influenced by vaping trends.”
Photo Credit: Courtesy of Concordia University

The health risks associated with consumption of tobacco and cannabis products are well-established by now. Much less understood are the risks associated with vaping, particularly flavored products popular with young adults.

It is an increasingly pressing issue: Statistics Canada says one in 10 Canadians aged 20 to 24 and one in 15 aged 15 to 19 reported to have vaped every day in 2022.

Writing in the journal Langmuir, Concordia researchers show how the e-cigarette additive tocopherol — an organic compound better known as vitamin E — and tocopherol acetate can damage the lungs. The study adds to the growing body of literature on what has become known as electronic cigarette or vaping product use–associated lung injury (EVALI).

When heated and inhaled, the compound embeds in the pulmonary surfactant, a nanoscopically thin lipid protein membrane coating the surface of the alveoli that regulates the oxygen-carbon dioxide gas exchange and stabilizes the lungs’ surface tension during breathing.

Scientists identify rare gene variants which confer up to 6-fold increase in risk of obesity

Photo Credit: Mart Production

The discovery of rare variants in the genes BSN and APBA1 are some of the first obesity-related genes identified for which the increased risk of obesity is not observed until adulthood.

The study, published in Nature Genetics, was led by researchers at the Medical Research Council (MRC) Epidemiology Unit and the MRC Metabolic Diseases Unit at the Institute of Metabolic Science, both based at the University of Cambridge.

The researchers used UK Biobank and other data to perform whole exome sequencing of body mass index (BMI) in over 500,000 individuals.

They found that genetic variants in the gene BSN, also known as Bassoon, can raise the risk of obesity as much as six times and was also associated with an increased risk of non-alcoholic fatty liver disease and of type 2 diabetes.

The Bassoon gene variants were found to affect 1 in 6,500 adults, so could affect about 10,000 people in the UK.

“It’s ultimately about predicting everything” – theory could be a map to hunted quantum materials

Photo Credit: Vendi Jukic Buca

A breakthrough in theoretical physics is an important step towards predicting the behavior of the fundamental matter of which our world is built. It can be used to calculate systems of enormous quantities of quantum particles, a feat thought impossible before. The University of Copenhagen research may prove of great importance for the design of quantum computers and could even be a map to superconductors that function at room-temperature.

On the fringes of theoretical physics, Berislav Buca investigates the nearly impossible by way of "exotic" mathematics. His latest theory is no exception. By making it possible to calculate the dynamics, i.e., movements and interactions, of systems with enormous quantities of quantum particles, it has delivered something that had been written off in physics. An impossibility made possible.

The unexpected presence of a white cat adorns the illustrations of Buca's research. Pulci the cat is his eye-catching muse. Arrows through the cat's body illustrate the quantum mechanical origin of the playful cat's movements – and this is precisely the relationship that Buca is trying to understand by making it possible to calculate the dynamics of the very smallest particles.

The breakthrough has reinvigorated an old and fundamental scientific question: Theoretically, if all behavior in the universe can be calculated by way of the laws of physics, can we then predict everything by calculating its smallest particles? 

Heat flows the secret to order in prebiotic molecular kitchen

Schematic visualization of heat flows in rock cracks.
Illustration Credit: Christof Mast

Life is complicated. What is true for our everyday existence also holds for the many complex processes that take place inside cells. Proteins constantly have to be synthesized, cell walls built, and DNA replicated. This can only work when reaction partners converge at the right time in sufficiently high concentrations while suffering little disruption from other substances. Over the course of billions of years, evolution has perfected these mechanisms and ensured that such vital processes occur with high efficiency at the correct place.

Circumstances were probably a lot more chaotic four billion years ago, when prebiotic reactions created the conditions for the emergence of the first lifeforms. For these reactions, too, it was necessary for the ‘right’ substances to be brought together at the ‘right’ time in one place, so that more complex biomolecules like RNA and amino acid chains could form. While such reactions are possible to recreate in the laboratory thanks to manual intermediate steps, it is highly challenging for them to come about in a simple ‘primordial soup’ – that is to say, a very dilute mixture of prebiotic building blocks. So how could nature create suitable conditions for the origin of life?

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