Insight into brain’s waste clearing system may shed light on brain diseases

The image shows a microscopic image revealing the enhanced glymphatic transport of an intranasally delivered tracer (red), achieved using ultrasound combined with microbubbles.
Image Credit: Chen lab

Like the lymphatic system in the body, the glymphatic system in the brain clears metabolic waste and distributes nutrients and other important compounds. Impairments in this system may contribute to brain diseases, such as neurodegenerative diseases and stroke.

A team of researchers in the McKelvey School of Engineering at Washington University in St. Louis has found a noninvasive and nonpharmaceutical method to influence glymphatic transport using focused ultrasound, opening the opportunity to use the method to further study brain diseases and brain function. Results of the work are published in Proceedings of the National Academy of Sciences May 15, 2023.

Hong Chen, associate professor of biomedical engineering in McKelvey Engineering and of neurological surgery in the School of Medicine, and her team, including Dezhuang (Summer) Ye, a postdoctoral research associate, and Si (Stacie) Chen, a former postdoctoral research associate, found the first direct evidence that focused ultrasound, combined with circulating microbubbles — a technique they call FUSMB — could mechanically enhance glymphatic transport in the mouse brain. 

Focused ultrasound can penetrate the scalp and skull to reach the brain and precisely target a defined region within the brain. In previous work, Chen’s team found that microbubbles injected into the bloodstream amplify the effects of the ultrasound waves on the blood vessels and generate a pumping effect, which helps with the accumulation of intranasally-delivered agents in the brain, such as drugs or gene therapy treatments.

New priming method improves battery life, efficiency

Quan Nguyen (left), Sibani Lisa Biswal and collaborators developed a prelithiation technique that helps improve the performance of lithium-ion batteries with silicon anodes.
Photo Credit: Jeff Fitlow/Rice University

Silicon anode batteries have the potential to revolutionize energy storage capabilities, which is key to meeting climate goals and unlocking the full potential of electric vehicles.

However, the irreversible depletion of lithium ions in silicon anodes puts a major constraint on the development of next-generation lithium-ion batteries.

Scientists at Rice University’s George R. Brown School of Engineering have developed a readily scalable method to optimize prelithiation, a process that helps mitigate lithium loss and improves battery life cycles by coating silicon anodes with stabilized lithium metal particles (SLMPs).

The Rice lab of chemical and biomolecular engineer Sibani Lisa Biswal found that spray-coating the anodes with a mixture of the particles and a surfactant improves battery life by 22% to 44%. Battery cells with a greater amount of the coating initially achieved a higher stability and cycle life. However, there was a drawback: When cycled at full capacity, a larger amount of the particle coating led to more lithium trapping, causing the battery to fade more rapidly in subsequent cycles.

Study reveals new ways for exotic quasiparticles to “relax”

By sandwiching bits of perovskite between two mirrors and stimulating them with laser beams, researchers were able to directly control the spin state of quasiparticles known as exciton-polariton pairs, which are hybrids of light and matter.
Illustration Credit: Courtesy of the researchers
(CC BY-NC-ND 3.0)

New findings from a team of researchers at MIT and elsewhere could help pave the way for new kinds of devices that efficiently bridge the gap between matter and light. These might include computer chips that eliminate inefficiencies inherent in today’s versions, and qubits, the basic building blocks for quantum computers, that could operate at room temperature instead of the ultracold conditions needed by most such devices.

The new work, based on sandwiching tiny flakes of a material called perovskite in between two precisely spaced reflective surfaces, is detailed in the journal Nature Communications, in a paper by MIT recent graduate Madeleine Laitz PhD ’22, postdoc Dane deQuilettes, MIT professors Vladimir Bulovic, Moungi Bawendi and Keith Nelson, and seven others.

By creating these perovskite sandwiches and stimulating them with laser beams, the researchers were able to directly control the momentum of certain “quasiparticles” within the system. Known as exciton-polariton pairs, these quasiparticles are hybrids of light and matter. Being able to control this property could ultimately make it possible to read and write data to devices based on this phenomenon.

NUS scientists develop a novel light-field sensor for 3D scene construction with unprecedented angular resolution

Prof Liu Xiaogang (right) and Dr Yi Luying from the NUS Department of Chemistry capturing a 3D image of a model using the light-field sensor.
Photo Credit: Courtesy of National University of Singapore

Color-encoding technique for light-field imaging has potential applications in fields such as autonomous driving, virtual reality and biological imaging

A research team from the National University of Singapore (NUS) Faculty of Science, led by Professor Liu Xiaogang from the Department of Chemistry, has developed a 3D imaging sensor that has an extremely high angular resolution, which is the capacity of an optical instrument to distinguish points of an object separated by a small angular distance, of 0.0018o. This innovative sensor operates on a unique angle-to-color conversion principle, allowing it to detect 3D light fields across the X-ray to visible light spectrum.  

A light field encompasses the combined intensity and direction of light rays, which the human eyes can process to precisely detect the spatial relationship between objects. Traditional light sensing technologies, however, are less effective. Most cameras, for instance, can only produce two-dimensional images, which is adequate for regular photography but insufficient for more advanced applications, including virtual reality, self-driving cars, and biological imaging. These applications require precise 3D scene construction of a particular space.

Jellybeans – a sweet solution for overcrowded circuitry in quantum computer chips

Engineers show that a jellybean-shaped quantum dot creates more breathing space in a microchip packed with qubits.

The silicon microchips of future quantum computers will be packed with millions, if not billions of qubits – the basic units of quantum information – to solve the greatest problems facing humanity. And with millions of qubits needing millions of wires in the microchip circuitry, it was always going to get cramped in there.

But now engineers at UNSW Sydney have made an important step towards solving a long-standing problem about giving their qubits more breathing space -- and it all revolves around jellybeans.

Not the kind we rely on for a sugar hit to get us past the 3pm slump. But jellybean quantum dots –elongated areas between qubit pairs that create more space for wiring without interrupting the way the paired qubits interact with each other.

As lead author Associate Professor Arne Laucht explains, the jellybean quantum dot is not a new concept in quantum computing, and has been discussed as a solution to some of the many pathways towards building the world’s first working quantum computer.

An unprecedented view of gene regulation

Caption:“Using this method, we generate the highest-resolution maps of the 3D genome that have ever been generated, and what we see are a lot of interactions between enhancers and promoters that haven't been seen previously,” says Anders Sejr Hansen, the Underwood-Prescott Career Development Assistant Professor of Biological Engineering at MIT. 

Video Credit: Melanie Gonick/MIT

Much of the human genome is made of regulatory regions that control which genes are expressed at a given time within a cell. Those regulatory elements can be located near a target gene or up to 2 million base pairs away from the target.

To enable those interactions, the genome loops itself in a 3D structure that brings distant regions close together. Using a new technique, MIT researchers have shown that they can map these interactions with 100 times higher resolution than has previously been possible.

“Using this method, we generate the highest-resolution maps of the 3D genome that have ever been generated, and what we see are a lot of interactions between enhancers and promoters that haven't been seen previously,” says Anders Sejr Hansen, the Underwood-Prescott Career Development Assistant Professor of Biological Engineering at MIT and the senior author of the study. “We are excited to be able to reveal a new layer of 3D structure with our high resolution.”

The researchers’ findings suggest that many genes interact with dozens of different regulatory elements, although further study is needed to determine which of those interactions are the most important to the regulation of a given gene.

The Trumpet biocomputing platform heralds a new path for medicine

A biocomputing chip made of bacteria.
Image Credit: College of Biological Sciences / University of Minnesota

From early detection and internal treatment of diseases to futuristic applications like augmenting human memory, biological computing, or biocomputing, it has the potential to revolutionize medicine and computers. Traditional computer hardware is limited in its ability to interface with living organs, which has constrained the development of medical devices. Computerized implants require a constant supply of electricity, they can cause scarring in soft tissue that makes them unusable and they cannot heal themselves the way organisms can. Through the use of biological molecules such as DNA or proteins, biocomputing has the potential to overcome these limitations.

Biocomputing is typically done either with live cells or with non-living, enzyme-free molecules. Live cells can feed themselves and can heal, but it can be difficult to redirect cells from their ordinary functions towards computation. Non-living molecules solve some of the problems of live cells, but have weak output signals and are difficult to fine-tune and regulate. 

Study unlocks potential breakthrough in Type 1 diabetes treatment

Omid Veiseh and Boram Kim. Kim is holding a medical-grade catheter similar to ones used in the study experiments.
Photo Credit: Gustavo Raskosky/Rice University

For the over 8 million people around the globe living with Type 1 diabetes, getting a host immune system to tolerate the presence of implanted insulin-secreting cells could be life-changing.

Rice University bioengineer Omid Veiseh and collaborators identified new biomaterial formulations that could help turn the page on Type 1 diabetes treatment, opening the door to a more sustainable, long-term, self-regulating way to handle the disease.

To do so, they developed a new screening technique that involves tagging each biomaterial formulation in a library of hundreds with a unique “barcode” before implanting them in live subjects.

According to the study in Nature Biomedical Engineering, using one of the alginate formulations to encapsulate human insulin-secreting islet cells provided long-term blood sugar level control in diabetic mice. Catheters coated with two other high-performing materials did not clog up.

“This work was motivated by a major unmet need,” said Veiseh, a Rice assistant professor of bioengineering and Cancer Prevention and Research Institute of Texas scholar. “In Type 1 diabetes patients, the body’s immune system attacks the insulin-producing cells of the pancreas. As those cells are killed off, the patient loses the ability to regulate their blood glucose.”

Chest E-Tattoo Boasts Major Improvements in Heart Monitoring

A new flexible, wearable medical device could provide a major boost in the fight against heart disease, the leading cause of death in the United States.
Photo Credit: University of Texas at Austin / Cockrell School of Engineering

A team led by researchers at The University of Texas at Austin has developed an ultrathin, lightweight electronic tattoo, or e-tattoo, that attaches to the chest for continuous, mobile heart monitoring outside of a clinical setting. It includes two sensors that together provide a clear picture of heart health, giving clinicians a better chance to catch red flags for heart disease early.

“Most heart conditions are not very obvious. The damage is being done in the background and we don’t even know it,” said Nanshu Lu, a professor in the Department of Aerospace and Engineering Mechanics and a lead author of the study. “If we can have continuous, mobile monitoring at home, then we can do early diagnosis and treatment, and if that can be done, 80% of heart disease can be prevented.”

The study is published in Advanced Electronic Materials.

A simple paper test could offer early cancer diagnosis

MIT engineers have designed a new nanoparticle sensor that can enable cancer diagnosis with a simple urine test. The nanoparticles (blue) carry DNA barcodes (zigzag lines) that can be cleaved by cancer-associated proteases in the body (pac-man shapes). Once cleaved, the DNA barcodes can be detected in a urine sample.
Illustration Credit: Courtesy of the researchers. Edited by MIT News

MIT engineers have designed a new nanoparticle sensor that could enable early diagnosis of cancer with a simple urine test. The sensors, which can detect many different cancerous proteins, could also be used to distinguish the type of a tumor or how it is responding to treatment.

The nanoparticles are designed so that when they encounter a tumor, they shed short sequences of DNA that are excreted in the urine. Analyzing these DNA “barcodes” can reveal distinguishing features of a particular patient’s tumor. The researchers designed their test so that it can be performed using a strip of paper, similar to an at-home Covid test, which they hope could make it affordable and accessible to as many patients as possible.

“We are trying to innovate in a context of making technology available to low- and middle-resource settings. Putting this diagnostic on paper is part of our goal of democratizing diagnostics and creating inexpensive technologies that can give you a fast answer at the point of care,” says Sangeeta Bhatia, the John and Dorothy Wilson Professor of Health Sciences and Technology and of Electrical Engineering and Computer Science at MIT and a member of MIT’s Koch Institute for Integrative Cancer Research and Institute for Medical Engineering and Science.

Condensed Matter Physics Inspires a New Model of Cellular Behavior

Model illustrating how cells exert pressure on one another, leading to extrusion.
Image Credit: Courtesy of S. Monfared

Cells are expert cooperators and collaborators. To maintain tissue health, cells talk to each other, exert pressure on each other, and kick out cells that are not contributing to the overall well-being of the collective. When it's time to get rid of a cell, the collective group initiates a process called cell extrusion. Cells can be extruded for a number of reasons—they could be cancerous, or old, or they simply could be overcrowding other cells. Extrusion is a necessary process for tissues to maintain health and integrity.

Biologists have long studied the biochemical cues and signals that underly cell extrusion, but the mechanical, physical forces involved are poorly understood.

Now, inspired by the mechanics of a phase of matter called liquid crystals, researchers have developed the first three-dimensional model of a layer of cells and the extrusion behavior that emerges from their physical interactions. From this new model, the team discovered that the more a cell is squeezed by its neighbors in a particular symmetric way, the more likely it is to get extruded from the group.

I’ll Have My Nano-Sized Donuts with Extra Swirls

Donut shaped skyrmions (left) show polarization swirls in one direction, while half-donut-shaped merons (right) are able to swirl in multiple directions.
Image Credit: Yu-Tsun Shao.

Swirling donuts. That’s what Yu-Tsun Shao thinks about when describing his atomic-scale materials research.

Shao, an assistant professor in the Mork Family Department of Chemical Engineering and Materials Science, aims to understand the atomic-scale behavior of donut-shaped particles that can enable low-power electronics. He has uncovered how strain and heat can shift the shape of the donut particle to give it powerful new energy-efficient and stabilizing properties. His latest work was recently published in Nature Communications.

Shao is working with skyrmions — nanometer-sized objects that resemble donut-like swirling vortexes. The skyrmions have electric polarization in the form of positive or negative charges (dipoles) that move in a continuous direction up and out from the center ‘donut hole” and down and in from the outer edge of the particle.

New blue light technique could enable advances in understanding nanoscale technologies

Photo Credit: Courtesy of Brown University

With a new microscopy technique that uses blue light to measure electrons in semiconductors and other nanoscale materials, a team of Brown University researchers is opening a new realm of possibilities in the study of these critical components, which can help power devices like mobile phones and laptops.

The findings are a first in nanoscale imaging and provide a workaround to a longstanding problem that has greatly limited the study of key phenomena in a wide variety of materials that could one day lead to more energy-efficient semiconductors and electronics. The work was published in Light: Science & Applications.

“There is a lot of interest these days in studying materials with nanoscale resolution using optics,” said Daniel Mittleman, a professor in Brown’s School of Engineering and author of the paper describing the work. “As the wavelength gets shorter, this becomes a lot harder to implement. As a result, nobody had ever done it with blue light until now.”

The wound dressing that can reveal infection

The wound dressing is made of tight mesh nanocellulose, preventing bacteria and other microbes from getting in. At the same time, the material lets gases and liquid through.
Photo Credit: Olof Planthaber

A nanocellulose wound dressing that can reveal early signs of infection without interfering with the healing process has been developed by researchers at Linköping University. Their study, published in Materials Today Bio, is one further step on the road to a new type of wound care.

The skin is the largest organ of the human body. A wound disrupts the normal function of the skin and can take a long time to heal, be very painful for the patient and may, in a worst-case scenario, lead to death if not treated correctly. Also, hard-to-heal wounds pose a great burden on society, representing about half of all costs in out-patient care.

In traditional wound care, dressings are changed regularly, about every two days. To check whether the wound is infected, care staff have to lift the dressing and make an assessment based on appearance and tests. This is a painful procedure that disturbs wound healing as the scab breaks repeatedly. The risk of infection also increases every time the wound is exposed.

Concordia researchers fight shallow lake algae blooms with floating filtration technique

Photo Credit: Liz Harrell

Climate change and human activity have been putting pressure on water bodies worldwide, and Canada’s vast network of lakes is no exception. Over the past decades, increasing nutrient levels have led to a process called eutrophication, in the shallow lakes dotting Quebec’s Laurentian region north of Montreal. These changes have led to a surge in algae blooms, rendering the lakes unusable and possibly disrupting the natural ecosystem.

Restoring these lakes to a healthier condition is a complicated and expensive undertaking, but a new method being investigated by Concordia researchers in the Department of Building, Civil and Environmental Engineering may cut down on both costs and labor in an environmentally friendly way.

Writing in the journal Water, the researchers describe a system of floating geotextile filters that efficiently remove suspended solids, algae and the nutrients from a shallow lake.  While the project is still in development, the researchers say they believe it has the potential to scale up. This technology could then benefit the health of larger bodies of water such as ponds, rivers, coastal areas and bays.

Breakthrough fix identified for earthquake-prone buildings

A cost-effective solution to strengthen Aotearoa New Zealand's riskiest buildings has been identified by researchers at Waipapa Taumata Rau, University of Auckland.

PhD candidate Victor Li, Dr Enrique del Rey Castillo and Dr Rick Henry from the Faculty of Engineering found that wrapping weak spots in concrete walls with carbon-fiber strips can strengthen high-rise buildings to resist earthquakes well beyond the demands of the building code.

The research was funded by Toka Tū Ake EQC to help find the most efficient and cost-effective ways to strengthen thin concrete walls.

The findings are likely to draw significant interest in the engineering sector as over 100 multi-story buildings in Wellington’s CBD alone are well below modern code.

Li says that thin concrete walls can deform out of plane due to their inherent instability, and just one percent of lateral displacement can cause catastrophic collapse.

Even as temperatures rise, this hydrogel material keeps absorbing moisture

MIT engineers have found that a common hydrogel has unique, super-soaking abilities. Even as temperatures climb, the transparent material continues to absorb moisture, and could serve to harvest water in desert regions, and passively regulate humidity in tropical climates.
Photo Credit: Felice Frankel

The vast majority of absorbent materials will lose their ability to retain water as temperatures rise. This is why our skin starts to sweat and why plants dry out in the heat. Even materials that are designed to soak up moisture, such as the silica gel packs in consumer packaging, will lose their sponge-like properties as their environment heats up.

But one material appears to uniquely resist heat’s drying effects. MIT engineers have now found that polyethylene glycol (PEG) — a hydrogel commonly used in cosmetic creams, industrial coatings, and pharmaceutical capsules — can absorb moisture from the atmosphere even as temperatures climb.

The material doubles its water absorption as temperatures climb from 25 to 50 degrees Celsius (77 to 122 degrees Fahrenheit), the team reports.

PEG’s resilience stems from a heat-triggering transformation. As its surroundings heat up, the hydrogel’s microstructure morphs from a crystal to a less organized “amorphous” phase, which enhances the material’s ability to capture water.

Researchers develop carbon-negative concrete

Graduate student Zhipeng Li and Professor Xianming Shi.
Photo Credit: Courtesy of Washington State University

A viable formula for a carbon-negative, environmentally friendly concrete that is nearly as strong as regular concrete has been developed at Washington State University.  

In a proof-of-concept work, the researchers infused regular cement with environmentally friendly biochar, a type of charcoal made from organic waste, that had been strengthened beforehand with concrete wastewater. The biochar was able to suck up to 23% of its weight in carbon dioxide from the air while still reaching a strength comparable to ordinary cement.   

The research could significantly reduce carbon emissions of the concrete industry, which is one of the most energy- and carbon-intensive of all manufacturing industries. The work, led by doctoral student Zhipeng Li, is reported in the journal Materials Letters.

“We’re very excited that this will contribute to the mission of zero-carbon built environment,” said Xianming Shi, professor in the WSU Department of Civil and Environmental Engineering and the corresponding author on the paper.

Graphene ‘tattoo’ treats cardiac arrhythmia with light

Graphene implant on tattoo paper
Photo Credit: Ning Liu/University of Texas at Austin

First graphene-based cardiac implant senses irregularities, then stimulates the heart

Researchers led by Northwestern University and the University of Texas at Austin (UT) have developed the first cardiac implant made from graphene, a two-dimensional super material with ultra-strong, lightweight and conductive properties.

Similar in appearance to a child’s temporary tattoo, the new graphene “tattoo” implant is thinner than a single strand of hair yet still functions like a classical pacemaker. But unlike current pacemakers and implanted defibrillators, which require hard, rigid materials that are mechanically incompatible with the body, the new device softly melds to the heart to simultaneously sense and treat irregular heartbeats. The implant is thin and flexible enough to conform to the heart’s delicate contours as well as stretchy and strong enough to withstand the dynamic motions of a beating heart.

After implanting the device into a rat model, the researchers demonstrated that the graphene tattoo could successfully sense irregular heart rhythms and then deliver electrical stimulation through a series of pulses without constraining or altering the heart’s natural motions. Even better: The technology also is optically transparent, allowing the researchers to use an external source of optical light to record and stimulate the heart through the device. 

Leaps in artificial blood research aim to improve product safety, efficacy

Artificial blood has been used in a variety of clinical trials, but no safe alternative has yet made it to market.
Image Credit: Narupon Promvichai

Researchers have made huge strides in ensuring that red blood cell substitutes – or artificial blood – are able to work safely and effectively when transfused into the bloodstream.  

The key is to make the artificial blood molecules big enough so they don’t leak from blood vessels into tissue and cause dangerous cardiovascular side effects, notes a new study led by researchers from The Ohio State University. 

Although blood loss is typically treated by transfusing units of donated blood, in cases where transfusions aren’t readily available or time is too limited to screen for patient blood type compatibility (such as in certain rural areas or on the battlefield), artificial blood products offer medical professionals more flexibility for treatment. In clinical trials, previous generations of these blood substitutes often resulted in several poor health outcomes, as individuals experienced symptoms ranging from narrowing of blood vessels and high blood pressure to tissue injury.   

In this study, researchers found that a certain sized fraction of red blood cell substitute can provide a range of health benefits, and can decrease the risk of cardiovascular side effects – if its components are the right size.