Focused ultrasound mediated liquid biopsy in a tauopathy mouse model

Hong Chen and her collaborators found that using focused-ultrasound-mediated liquid biopsy in a mouse model released more tau proteins and another biomarker for neurodegenerative disorders into the blood than without the intervention. This noninvasive method could facilitate diagnosis of neurodegenerative disorders.
Illustration Credit: Chen lab

Several progressive neurodegenerative disorders, including Alzheimer’s disease, are defined by having tau proteins in the brain. Researchers are seeking to identify the mechanisms behind these tau proteins to develop treatments, however, their efforts to detect biomarkers in blood has been hampered by the protective blood-brain barrier.

At Washington University in St. Louis, new research from the lab of Hong Chen, associate professor of biomedical engineering in the McKelvey School of Engineering and of radiation oncology in the School of Medicine, and collaborators found that using focused-ultrasound-mediated liquid biopsy in a mouse model released more tau proteins and another biomarker into the blood than without the intervention. This noninvasive method could facilitate diagnosis of neurodegenerative disorders, the researchers said.

The method, known as sonobiopsy, uses focused ultrasound to target a precise location in the brain. Once located, the researchers inject microbubbles into the blood that travel to the ultrasound-targeted tissue and pulsate, which safely opens the blood-brain barrier. The temporary openings allow biomarkers, such as tau proteins and neurofilament light chain protein (NfL), both indicative of neurodegenerative disorders, to pass through the blood-brain barrier and release into the blood.

Probe can measure both cell stiffness and traction, researchers report

Professor Ning Wang, front right, is joined by researchers, from left, Fazlur Rashid, Kshitij Amar and Parth Bhala.
Photo Credit: Fred Zwicky

Scientists have developed a tiny mechanical probe that can measure the inherent stiffness of cells and tissues as well as the internal forces the cells generate and exert on one another. Their new “magnetic microrobot” is the first such probe to be able to quantify both properties, the researchers report, and will aid in understanding cellular processes associated with development and disease.

They detail their findings in the journal Science Robotics.

“Living cells generate forces through protein interactions, and it’s very hard to measure these forces,” said Ning Wang, a professor of mechanical science and engineering at the University of Illinois Urbana-Champaign who led the research. “Most probes can either measure the forces actively generated by the tissues and cells themselves, a trait we call traction, or they can measure their stiffness – but not both.”

To measure cell stiffness, researchers need a relatively rigid probe that can compress, stretch or twist the tissues and quantify how robustly they resist. But to measure the cells’ own internally generated contractions or expansions, a probe must be relatively soft and supple.

Like other scientists, Wang and his colleagues had already developed probes to measure each of these qualities individually. But he said he wanted to develop a more universal probe that could tackle both at once. Such a probe would allow a better understanding of how these properties influence diseases like arteriosclerosis or cancer, or how an embryo develops, for example.

Fish sensory organ key to improving navigational skills of underwater robots

Yellow blaze African cichlid
Photo Credit: Sarah Page

Scientists, led by the University of Bristol, have been studying a fish sensory organ to understand cues for collective behavior which could be employed on underwater robots.

This work was centered around the lateral line sensing organ in African cichlid fish, but found in almost all fish species, that enables them to sense and interpret water pressures around them with enough acuity to detect external influences such as neighboring fish, changes in water flow, predators and obstacles.

The lateral line system as a whole is distributed over the head, trunk and tail of the fish. It is comprised of mechanoreceptors (neuromasts) that are either within subdermal channels or on the surface of the skin.

Lead author Elliott Scott of the University of Bristol’s Department of Engineering Mathematics explained: “We were attempting to find out if the different areas of the lateral line - the lateral line on the head versus the lateral line on the body, or the different types of lateral line sensory units such as those on the skin, versus those under it, play different roles in how the fish is able to sense its environment through environmental pressure readings.

Plasma thrusters used on satellites could be much more powerful

The chamber where prof. Benjamin Jorns’ team tests the new Hall plasma thruster at the PEPL lab on the University of Michigan’s North Campus.
Photo Credit: Marcin Szczepanski/Lead Multimedia Storyteller, University of Michigan College of Engineering

It was believed that running more propellant through a Hall thruster would wreck its efficiency, but new experiments suggest they might power a crewed mission to Mars

It was believed that Hall thrusters, an efficient kind of electric propulsion widely used in orbit, need to be large to produce a lot of thrust. Now, a new study from the University of Michigan suggests that smaller Hall thrusters can generate much more thrust—potentially making them candidates for interplanetary missions.

“People had previously thought that you could only push a certain amount of current through a thruster area, which in turn translates directly into how much force or thrust you can generate per unit area,” said Benjamin Jorns, U-M associate professor of aerospace engineering who led the new Hall thruster study to be presented at the AIAA SciTech Forum in National Harbor, Maryland, today.

Soft robots harness viscous fluids for complex motions

Soft Robot
Video Credit: Courtesy of Collective Embodied Intelligence Lab | Cornell University 

One of the virtues of untethered soft robots is their ability to mechanically adapt to their surroundings and tasks, making them ideal for a range of roles, from tightening bolts in a factory to conducting deep-sea exploration. Now they are poised to become even more agile and controlled.

A team of researchers led by Kirstin Petersen, assistant professor of electrical and computer engineering in the College of Engineering, designed a new – and surprisingly simple – system of fluid-driven actuators that enable soft robots to achieve more complex motions. The researchers accomplished this by taking advantage of the very thing – viscosity – that had previously stymied the movement of such robots.

The team’s paper, “Harnessing Nonuniform Pressure Distributions in Soft Robotic Actuators,” published Jan. 20 in Advanced Intelligent Systems. The paper’s lead author is postdoctoral researcher Yoav Matia.

New Tool Uses Ultrasound ‘Tornado’ to Break Down Blood Clots

Ultrasonic Tornado
Illustration Credit: Xiaoning Jiang / Courtesy of North Carolina State University

Researchers have developed a new tool and technique that uses “vortex ultrasound” – a sort of ultrasonic tornado – to break down blood clots in the brain. The new approach worked more quickly than existing techniques to eliminate clots formed in an in vitro model of cerebral venous sinus thrombosis (CVST).

“Our previous work looked at various techniques that use ultrasound to eliminate blood clots using what are essentially forward-facing waves,” says Xiaoning Jiang, co-corresponding author of a paper on the work. “Our new work uses vortex ultrasound, where the ultrasound waves have a helical wavefront.

“In other words, the ultrasound is swirling as it moves forward,” says Jiang, who is the Dean F. Duncan Professor of Mechanical and Aerospace Engineering at North Carolina State University. “Based on our in vitro testing, this approach eliminates blood clots more quickly than existing techniques, largely because of the shear stress induced by the vortex wave.”

“The fact that our new technique works quickly is important, because CVST clots increase pressure on blood vessels in the brain,” says Chengzhi Shi, co-corresponding author of the work and an assistant professor of mechanical engineering at Georgia Tech. “This increases the risk of a hemorrhage in the brain, which can be catastrophic for patients.

Stanford Medicine researchers measure thousands of molecules from a single drop of blood

A single drop of blood can yield measurements for thousands of proteins, fats and other biomarkers, researchers at Stanford Medicine found.
Photo Credit: PublicDomainPictures

Researchers at Stanford Medicine have shown they can measure thousands of molecules — some of which are signals of health — from a single drop of blood.

The new approach combines a microsampling device — a tool used to self-administer a finger prick — with “multi-omics” technologies, which simultaneously analyze a vast array of proteins, fats, by-products of metabolism and inflammatory markers.

“Even more importantly, we’ve shown you can collect the blood drop at home and mail it into the lab,” said Michael Snyder, PhD, director of the Center for Genomics and Personalized Medicine and senior author on the research, which was published in Nature Biomedical Engineering on Jan. 19.

Unlike finger-prick testing for diabetes, which measures a single type of molecule (glucose), multi-omics microsampling gives data about thousands of different molecules at once.

The research sounds similar to a well-known approach promoted in the past for testing a single drop of blood, but there are important differences: While the earlier approach was based on replicating existing diagnostic tests, multi-omic microsampling uses a different type of data analysis based on a technology called mass spectrometry, which sorts molecules based on their mass and electronic charge. In addition, the data analysis is performed in a lab, not in a portable box.

Removing water, stains, contaminants with hydrogel beads

Snapshots of the hydrogel bead impacting the droplet causing the droplet to lift off the surface.
Photo Credit: Courtesy of University of Hawaiʻi

There may be a more efficient future for water repellent materials and methods thanks to new research from the University of Hawaiʻi at Mānoa College of Engineering. Associate Professor John S. Allen III and an international team of researchers have discovered a method to remove liquid from non-stick surfaces using hydrogel beads, a material similar to gel cap medications.

“Ever want to remove a puddle completely without touching it? How about removing staining coffee off your clothes? Do you know that all the dangerous contaminants are off the surface? All these might be facilitated with low-cost hydrogel beads in the future,” Allen explained.

For a variety of everyday and industrial waterproof/water resistant objects, it is important to reduce the contact time of an impacting water or liquid drop with the surface. Many people are familiar with water repellent coating on buildings and on clothing. Repellants are also used to mitigate icing on a plane, as bouncing droplets are less likely to have time to freeze.

Getting under your skin for better health

UC College of Engineering and Applied Science professor Jason Heikenfeld in his Novel Devices Lab.
 Photo Credit: Andrew Higley/UC Marketing + Brand

The next frontier of continuous health monitoring could be skin deep.

Biomedical engineers at the University of Cincinnati say interstitial fluid, the watery fluid found between and around cells, tissues or organs in the body, could provide an excellent medium for early disease diagnosis or long-term health monitoring.

In a paper published in the journal Nature Biomedical Engineering, they outlined the potential advantages and technological challenges of using interstitial fluid.

“Why we see it as a valuable diagnostic fluid is continuous access. With blood, you can’t easily take continuous readings,” said UC doctoral graduate Mark Friedel, co-lead author of the study.

“Can you imagine going about your day with a needle stuck in your vein all day? So, we need other tools.”

Microelectronics give researchers a remote control for biological robots

Remotely controlled miniature biological robots have many potential applications in medicine, sensing and environmental monitoring.   
Photo Credit: Yongdeok Kim

First, they walked. Then, they saw the light. Now, miniature biological robots have gained a new trick: remote control.

The hybrid “eBiobots” are the first to combine soft materials, living muscle and microelectronics, said researchers at the University of Illinois Urbana-Champaign, Northwestern University and collaborating institutions. They described their centimeter-scale biological machines in the journal Science Robotics.

“Integrating microelectronics allows the merger of the biological world and the electronics world, both with many advantages of their own, to now produce these electronic biobots and machines that could be useful for many medical, sensing and environmental applications in the future,” said study co-leader Rashid Bashir, an Illinois professor of bioengineering and dean of the Grainger College of Engineering.

Cyborg Cells Could Be Tools for Health and Environment

UC Davis biomedical engineers have created semi-living “cyborg cells” that have many of the capabilities of living cells but are unable to divide and grow. The cells could have applications in medicine and environmental cleanup.
Illustration Credit: Cheemeng Tan, UC Davis.

Biomedical engineers at the University of California, Davis, have created semi-living “cyborg cells.” Retaining the capabilities of living cells, but unable to replicate, the cyborg cells could have a wide range of applications, from producing therapeutic drugs to cleaning up pollution. The work was published in Advanced Science.

Synthetic biology aims to engineer cells that can carry out novel functions. There are essentially two approaches in use, said Cheemeng Tan, associate professor of biomedical engineering at UC Davis and senior author on the paper. One is to take a living bacterial cell and remodel its DNA with new genes that give it new functions. The other is to create an artificial cell from scratch, with a synthetic membrane and biomolecules.

The first approach, an engineered living cell, has great flexibility but is also able to reproduce itself, which may not be desirable. A completely artificial cell cannot reproduce but is less complex and only capable of a limited range of tasks.

Wearable, Printable, Shapeable Sensors Detect Pathogens and Toxins in the Environment

“Using the sensor, we can pick up trace levels of airborne SARS-CoV-2, or we can imagine modifying it to adapt to whatever the next public health threat might be,” Omenetto said. Here, a sensor is embedded on a drone.
Photo Credit: Courtesy of Silklab

Researchers at Tufts School of Engineering have developed a way to detect bacteria, toxins, and dangerous chemicals in the environment using a biopolymer sensor that can be printed like ink on a wide range of materials, including wearable items such as gloves, masks, or everyday clothing.

Using an enzyme similar to that found in fireflies, the sensor glows when it detects these otherwise invisible threats. The new technology is described in the journal Advanced Materials.

The biopolymer sensor, which is based on computationally designed proteins and silk fibroin extracted from the cocoons of the silk moth Bombyx Mori, can also be embedded in films, sponges, and filters, or molded like plastic to sample and detect airborne and waterborne dangers, or used to signal infections or even cancer in our bodies.

The researchers demonstrated how the sensor emits light within minutes as it detects the SARS-CoV-2 virus that causes COVID, anti-hepatitis B virus antibodies, the food-borne toxin botulinum neurotoxin B, or human epidermal growth factor receptor 2 (HER2), an indicator of the presence of breast cancer.

Controlled, localized delivery of blood thinner may improve blood clot treatment

Co-authors Atip Lawanprasert (left), doctoral student in biomedical engineering, Sopida Pimcharoen (center), undergraduate student in biomedical engineering and Scott Medina (right), Penn State associate professor of biomedical engineering, analyze results related to their study of combining the anticoagulant heparin with peptide to slow down the medication's delivery at the site of a blood clot.
Photo Credit: Jeff Xu / Pennsylvania State University

Heparin has long been used as a blood thinner, or anticoagulant, for patients with blood clotting disorders or after surgery to prevent complications. But the medication remains difficult to dose correctly, potentially leading to overdosing or underdosing.

A team of Penn State researchers combined heparin with a protein fragment, peptide, to slow down the release of the drug and convey the medication directly to the site of a clot. They published their findings in the journal Small.

“We wanted to develop a material that can gradually deliver heparin over time rather than the current iteration that gets cleared from the body in a couple of hours,” said corresponding author Scott Medina, Penn State associate professor of biomedical engineering. “We also wanted to deliver the drug through the skin instead of through an IV.”

When mixed, positively charged peptides and negatively charged heparin bind to create a nanogranular paste that can be injected under the skin, forming a cache of material that is then diffused in the circulatory system and travels to blood clots when they appear. The turbulent flow of fluid near a blood clot triggers the two materials to separate, allowing heparin to begin its anticoagulating action.

UCR scientists develop method to turn plastic waste into potentially valuable soil additive

Recent rain storms washed plastic waste into a creek bed in Riverside's Fairmount Park.
Photo Credit: David Danelski/UCR

University of California, Riverside, scientists have moved a step closer to finding a use for the hundreds of millions of tons of plastic waste produced every year that often winds up clogging streams and rivers and polluting our oceans.

In a recent study, Kandis Leslie Abdul-Aziz, a UCR assistant professor of chemical and environmental engineering, and her colleagues detailed a method to convert plastic waste into a highly porous form of charcoal or char that has a whopping surface area of about 400 square meters per gram of mass.

Such charcoal captures carbon and could potentially be added to soil to improve soil water retention and aeration of farmlands. It could also fertilize the soil as it naturally breaks down. Abdul-Aziz, however, cautioned that more work needs to be done to substantiate the utility of such char in agriculture.

The plastic-to-char process was developed at UC Riverside’s Marlan and Rosemary Bourns College of Engineering. It involved mixing one of two common types of plastic with corn waste — the leftover stalks, leaves, husks, and cobs — collectively known as corn stover. The mix was then cooked with highly compressed hot water, a process known as hydrothermal carbonization.

Self-powered, printable smart sensors created from emerging semiconductors could mean cheaper, greener Internet of Things

Simon Fraser University professor Vincenzo Pecunia
Photo Credit: Courtesy of Simon Fraser University

Creating smart sensors to embed in our everyday objects and environments for the Internet of Things (IoT) would vastly improve daily life—but requires trillions of such small devices. Simon Fraser University professor Vincenzo Pecunia believes that emerging alternative semiconductors that are printable, low-cost and eco-friendly could lead the way to a cheaper and more sustainable IoT.

Leading a multinational team of top experts in various areas of printable electronics, Pecunia has identified key priorities and promising avenues for printable electronics to enable self-powered, eco-friendly smart sensors. His forward-looking insights are outlined in his paper published on Dec. 28 in Nature Electronics.

“Equipping everyday objects and environments with intelligence via smart sensors would allow us to make more informed decisions as we go about in our daily lives,” says Pecunia. “Conventional semiconductor technologies require complex, energy-intensity, and expensive processing, but printable semiconductors can deliver electronics with a much lower carbon footprint and cost, since they can be processed by printing or coating, which require much lower energy and materials consumption.”

Researchers Demonstrate New Strain Sensors in Health Monitoring, Machine Interface Tech

Image Credit: Shuang Wu.

Researchers at North Carolina State University have developed a stretchable strain sensor that has an unprecedented combination of sensitivity and range, allowing it to detect even minor changes in strain with greater range of motion than previous technologies. The researchers demonstrated the sensor’s utility by creating new health monitoring and human-machine interface devices.

Strain is a measurement of how much a material deforms from its original length. For example, if you stretched a rubber band to twice its original length, its strain would be 100%.

“And measuring strain is useful in many applications, such as devices that measure blood pressure and technologies that track physical movement,” says Yong Zhu, corresponding author of a paper on the work and the Andrew A. Adams Distinguished Professor of Mechanical and Aerospace Engineering at NC State.

“But to date there’s been a trade-off. Strain sensors that are sensitive – capable of detecting small deformations – cannot be stretched very far. On the other hand, sensors that can be stretched to greater lengths are typically not very sensitive. The new sensor we’ve developed is both sensitive and capable of withstanding significant deformation,” says Zhu. “An additional feature is that the sensor is highly robust even when over-strained, meaning it is unlikely to break when the applied strain accidently exceeds the sensing range.”

Daylong wastewater samples yield surprises

Rice University engineers compared wastewater “grabs” to daylong composite samples and found the grab samples were more likely to result in bias in testing for the presence of antibiotic-resistant genes.
 Illustration Credit: Stadler Research Group/Rice University

Testing the contents of a simple sample of wastewater can reveal a lot about what it carries, but fails to tell the whole story, according to Rice University engineers.

Their new study shows that composite samples taken over 24 hours at an urban wastewater plant give a much more accurate representation of the level of antibiotic-resistant genes (ARGs) in the water. According to the Centers for Disease Control and Prevention (CDC), antibiotic resistance is a global health threat responsible for millions of deaths worldwide.

In the process, the researchers discovered that while secondary wastewater treatment significantly reduces the amount of target ARG, chlorine disinfectants often used in later stages of treatment can, in some situations, have a negative impact on water released back into the environment.

The lab of Lauren Stadler at Rice’s George R. Brown School of Engineering reported seeing levels of antibiotic-resistant RNA concentrations 10 times higher in composite samples than what they see in “grabs,” snapshots collected when flow through a wastewater plant is at a minimum.

UCLA-developed soft brain probe could be a boon for depression research

 Illustration of the soft probe with aptamer biosensors implanted in the brain.
Illustration Credit: Zhao, et al., 2022

Anyone familiar with antidepressants like Prozac or Wellbutrin knows that these drugs boost levels of neurotransmitters in the brain like serotonin and dopamine, which are known to play an important role in mood and behavior.

It might come as a surprise, then, that scientists still have very little data about the specific relationship between neurotransmitters — chemicals that relay messages from one brain cell to others — and our psychological states. Simply put, monitoring fluctuations of these neurochemicals in living brains has proved a persistent challenge.

Now, for the first time, UCLA scientists have attached nanoscale biochemical sensors, which are tuned to identify specific neurotransmitters, to a soft, implantable brain probe in order to continuously monitor these chemicals in real time. The new brain probe, described in a paper published in ACS Sensors, would allow scientists to track neurotransmitters in laboratory animals — and, ultimately, humans — during their day-to-day activities.

Pollution cleanup method destroys toxic “forever chemicals”

Ultraviolet light used for water treatment 
Photo Credit: UCR/Liu Lab

An insidious category of carcinogenic pollutants known as “forever chemicals” may not be so permanent after all.

University of California, Riverside, chemical engineering and environmental scientists recently published new methods to chemically break up these harmful substances found in drinking water into smaller compounds that are essentially harmless.

The patent-pending process infuses contaminated water with hydrogen, then blasts the water with high-energy, short-wavelength ultraviolet light. The hydrogen polarizes water molecules to make them more reactive, while the light catalyzes chemical reactions that destroy the pollutants, known as PFAS or poly- and per-fluoroalkyl substances.

This one-two punch breaks the strong fluorine-to-carbon chemicals bonds that make these pollutants so persistent and accumulative in the environment. In fact, the molecular destruction of PFAS increased from 10% to nearly 100% when compared to other ultraviolet water-treatment methods, while no other undesirable byproducts or impurities are generated, the UCR scientists reported in a paper recently published in the Journal of Hazardous Materials Letters.

Surveilling carbon sequestration: A smart collar to sense leaks

Sandia National Laboratories’ smart collar detecting a leak from a carbon dioxide storage reservoir.

 Animation Credit: Max Schwaber

Sandia National Laboratories engineers are working on a device that would help ensure captured carbon dioxide stays deep underground — a critical component of carbon sequestration as part of a climate solution.

Carbon sequestration is the process of capturing CO2 — a greenhouse gas that traps heat in the Earth’s atmosphere — from the air or where it is produced and storing it underground. However, there are some technical challenges with carbon sequestration, including making sure that the CO2 remains underground long term. Sandia’s wireless device pairs with tiny sensors to monitor for CO2 leaks and tell above-ground operators if one happens — and it lasts for decades.

“The world is trying a whole lot of different ways to reduce the production of CO2 to mitigate climate change,” said Andrew Wright, Sandia electrical engineer and project lead. “A complementary approach is to reduce the high levels of CO2 in the atmosphere by collecting a good chunk of it and storing it deep underground. The technology we’re developing with the University of Texas at Austin aims to determine whether the CO2 stays down there. What is special about this technology is that we’ll be monitoring it wirelessly and thus won’t create another potential path for leakage like a wire or fiber.”