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Scientists revive activity in frozen mouse brains for the first time

A familiar trope in science fiction is the cryopreserved time traveller, their body deep-frozen in suspended animation, then thawed and reawakened in another decade or century with all of their mental and physical capabilities intact.

Researchers attempting the cryogenic freezing and thawing of brain tissue from humans and other animals — mostly young vertebrates — have already shown that neuronal tissue can survive freezing on a cellular level and, after thawing, a functional one to some extent. But it has not been possible to fully restore the processes necessary for proper brain functioning — neuronal firing, cell metabolism and brain plasticity.

A team in Germany has now demonstrated a method for cryopreserving and thawing mouse brains that leaves some of this functionality intact. The study, published on 3 March in Proceedings of the National Academy of Sciences 3, details the authors’ use of a method called vitrification, which preserves tissue in a glass-like state, along with a thawing process that preserves living tissue.

“If brain function is an emergent property of its physical structure, how can we recover it from complete shutdown?” asks Alexander German, a neurologist at the University of Erlangen–Nuremberg in Germany and lead author of the study. The findings, he says, hint at the potential to one day protect the brain during disease or in the wake of severe injury, set up organ banks and even achieve whole-body cryopreservation of mammals.

Mrityunjay Kothari, who studies mechanical engineering at the University of New Hampshire in Durham, agrees that the study advances the state of the art in cryopreservation of brain tissue. “This kind of progress is what gradually turns science fiction into scientific possibility,” he says. However, he adds that applications such as the long-term banking of large organs or mammals remain far beyond the capabilities of the study.

Article Featured in Nature.


Micro Planets: Building Artificial Worlds with Black Hole Cores

What if we built entire planets around tiny black holes? Explore engineered micro worlds, artificial gravity, and the future of compact megastructures.

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Watch my exclusive video Lazarus Protocols: https://nebula.tv/videos/isaacarthur–… out Practical Engineering: https://nebula.tv/practical-engineeri… 🛒 SFIA Merchandise: https://isaac-arthur-shop.fourthwall… 🌐 Visit our Website: http://www.isaacarthur.net ❤️ Support us on Patreon: / isaacarthur ⭐ Support us on Subscribestar: https://www.subscribestar.com/isaac-a… 👥 Facebook Group: / 1,583,992,725,237,264 📣 Reddit Community: / isaacarthur 🐦 Follow on Twitter / X: / isaac_a_arthur 💬 SFIA Discord Server: / discord Credits: Micro Planets — Building Artificial Worlds with Black Hole Cores Written, Produced & Narrated by: Isaac Arthur Graphics from Jeremy Jozwik & Ken York Music Courtesy of Chris Zabriskie & Stellardrone Select imagery/video supplied by Getty Images Chapters 0:00 Intro 1:14 Small Worlds, Big Numbers 7:54 What to make it from? 11:53 What is a Micro Planet, and what is it like? 17:50 So could you go even smaller? 21:20 Nebula.
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Credits:
Micro Planets — Building Artificial Worlds with Black Hole Cores.
Written, Produced & Narrated by: Isaac Arthur.
Graphics from Jeremy Jozwik & Ken York.
Music Courtesy of Chris Zabriskie & Stellardrone.
Select imagery/video supplied by Getty Images.

Chapters.
0:00 Intro.
1:14 Small Worlds, Big Numbers.
7:54 What to make it from?
11:53 What is a Micro Planet, and what is it like?
17:50 So could you go even smaller?
21:20 Nebula

Catch-bond engineering “turbocharge” T cells to attack prostate cancer

T cells are a powerful weapon in the fight against cancer, forming the basis of treatments such as CAR-T cell therapy and checkpoint inhibitors. This research centers on another type of immunotherapy approach called T cell receptor (TCR) therapy, which engineers T cells to recognize specific proteins on cancer cells, allowing for highly targeted attacks.

Many of these proteins, however, are “self-antigens,” or molecules normally found in the body. To prevent these T cells from attacking healthy tissue, the immune system naturally eliminates the strongest cancer-fighting T cells during development. This leaves behind weaker T cell receptors that may struggle to recognize and destroy tumors, particularly those that have learned to evade immune defenses.

To overcome this challenge, researchers focused on fine-tuning naturally occurring T cell receptors to strengthen their ability to recognize a common prostate cancer protein called prostatic acid phosphatase (PAP), which is commonly expressed on prostate tissue and prostate tumors. The team identified a naturally weak TCR, known as TCR156, that could detect PAP but was not strong enough to effectively kill cancer cells.

Using a novel technique called catch bond engineering, a concept developed by the Lab, the researchers “turbocharged” the T cells. In the body, T cells form brief, mechanical bonds with their targets, known as catch bonds, which help them sense and respond to threats. By altering just one or two amino acids in the T cell receptor, the scientists were able to strengthen these bonds while preserving the T cells’ natural ability to recognize their specific target.

Multiple engineered versions of TCR156 were created and tested. Two candidates proved to be the most effective. These engineered T cells were analyzed for their ability to recognize tumors, release cancer-killing molecules, proliferate, and resist exhaustion. Advanced imaging, single-cell RNA sequencing, and structural analyses were used to confirm that the modifications improved T cell function while maintaining precision and avoiding off-target effects.

Structural and computer modeling studies showed that the catch bond mutations did not change the overall TCR shape but primed it to form a new interaction with PAP when the T cell engaged the tumor, explaining how the engineered T cells could remain highly specific while dramatically boosting their cancer-killing ability.

The researchers found that a single amino acid change created a catch bond hotspot that significantly enhanced T cell function. This change did not directly contact the cancer protein until the T cell engaged dynamically, demonstrating that a tiny modification can have a major effect. Most importantly, the modifications did not make the cells attack healthy tissue.

Painless skin patch offers new way to monitor immune health

Researchers at The Jackson Laboratory (JAX), in collaboration with the Massachusetts Institute of Technology (MIT), have developed the first bandage-like microneedle patch that can sample the body’s immune responses painlessly from the skin. The device detects inflammatory signals within minutes and collects specialized immune cells within hours without the need for blood draws or surgical biopsies.

Already, the patch is helping researchers and clinicians study immune responses in aging and skin autoimmunity, including vitiligo and psoriasis. In the future, it could make it easier to track how people respond to vaccines, infections, and cancer therapies by complementing traditional blood tests and biopsies while being far easier on patients.

The study appears in Nature Biomedical Engineering.

New X-ray vision for electronics lets scientists monitor working chips remotely

A team of international researchers have developed a breakthrough way to observe what is happening inside electronic chips while they are operating—without touching them, taking them apart, or switching them off. The new technique uses terahertz waves, a safe and non-ionizing form of electromagnetic radiation, to detect tiny movements of electrical charge inside fully packaged semiconductor devices. For the first time, this allows scientists and engineers to monitor electronic components as they function in the real world.

The study, published in the IEEE Journal of Microwaves, involves researchers from Adelaide University in Australia, US technology company Virginia Diodes Inc, the Hasso Plattner Institute and the University of Potsdam, Germany.

Adelaide University Group Leader of the Terahertz Engineering Laboratory (TEL), Professor Withawat Withayachumnankul, said that semiconductors underpin almost every modern technology, from smartphones and medical devices to vehicles, power grids and defense systems.

Topology helps build more robust photonic networks

Penn-led researchers have shown for the first time that multiple, information-carrying light signals can be safely guided through chip-based, reconfigurable networks using topology, the esoteric branch of mathematics that says donuts and mugs are identical. Because topological properties remain stable even when objects are deformed—hence the field equating mugs and donuts, since both have one opening—the advance could help make light-based technologies for computing and communications more powerful and reliable.

“We already knew how to guide light using topology,” says Liang Feng, Professor in Materials Science and Engineering (MSE) with a secondary appointment in Electrical and Systems Engineering (ESE) within Penn Engineering and senior author of a study in Nature Physics describing the result. “But we had never been able to guide multiple, concurrent signals before.”

That opens the door to building networks of chips that communicate using light while taking advantage of the robustness topology provides. “Signals guided by these principles can be extremely reliable,” says Feng. “It’s like building a highway for light where even large potholes have no effect on traffic—it’s as if the defects simply aren’t there.”

Nano 3D metallic parts turn out to be surprisingly strong despite defects

Scientists at Caltech have figured out how to precisely engineer tiny three-dimensional (3D) metallic pieces with nanoscale dimensions. The process can work with any metal or metal alloy and yields components of surprising strength despite having a porous and defect-ridden microstructure, making it potentially useful in a wide range of applications, including medical devices, computer chips, and equipment needed for space missions.

The scientists describe their method in a paper published in the journal Nature Communications. The work was completed in the lab of Julia R. Greer, the Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering at Caltech, and Huajian Gao of Tsinghua University in Beijing.

The researchers use a technique called two-photon lithography that allows them to sequentially build an object of a desired size and shape by carefully controlling the geometry at the level of individual voxels, the smallest distinguishable volumes, or features, in a 3D image. Beginning with a light-sensitive liquid, the scientists use a tightly focused femtosecond laser beam—a femtosecond is 1 quadrillionth of a second—to build a desired shape out of a gel-like material called hydrogel. After infusing the miniature hydrogel sculpture with metallic salts, such as copper nitrate or nickel nitrate, they heat the structure twice in a specialized furnace to produce a shrunken metallic replica of the original shape.

Scientists create a new state of matter at room temperature using light and nanostructures

Researchers at Rensselaer Polytechnic Institute (RPI) have created a new and unusual state of matter—known as a supersolid—by engineering how light and matter interact inside a nanoscale device. The work, published in Nature Nanotechnology, demonstrates that this exotic quantum phase can exist at room temperature, overcoming a long-standing limitation in the field.

Supersolids are unusual because they combine two seemingly incompatible properties: Like a solid, they form an ordered, crystal-like structure. At the same time, they behave like a fluid, meaning they can flow without resistance. Until now, such states have only been observed under extremely cold conditions, close to absolute zero.

“Our work shows that you can create and control this exotic state using light,” said Wei Bao, Ph.D., assistant professor in the Department of Materials Science and Engineering at RPI and senior author of the study. “What’s especially exciting is that it happens at room temperature, in a platform that can be engineered and potentially scaled.”

A clear roadmap for engineering combs of light

Optical frequency combs—laser sources that emit evenly spaced colors of light—are foundational, ubiquitous tools for precision measurement, found in optical clocks, gas-sensing spectrometers, and instruments that detect the light signatures of exoplanets. Traditionally, frequency combs are produced by large, fiber-laser systems ranging from the size of a shoebox to a refrigerator.

Engineers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) are at the forefront of shrinking these powerful laser sources onto photonic chips to make “microcombs” at millimeter to micron scales, useful not only for their smaller size, but in next-generation telecommunications applications, such as generating multiple data carriers over a single optical fiber.

New research led by Marko Lončar, the Tiantsai Lin Professor of Electrical Engineering and Applied Physics, describes a new, generalized model for how to design so-called resonant electro-optic microcombs on thin-film lithium niobate, a material featuring a strong electro-optic effect, or the ability to efficiently mix electronic signals with optical ones.

RNA barcodes fast-track brain connection mapping

“When engineering a computer, you need to know the circuitry of the central processing unit. If you don’t know how everything is wired together, you can’t understand its function, optimize it or fix it when something breaks. We are approaching the brain the same way,” said study leader Boxuan Zhao, a professor of cell and developmental biology at the University of Illinois Urbana-Champaign.

“Our technology enables simultaneous mapping of thousands of neural connections with single-synapse resolution —a capability that doesn’t exist in any current technology. It is directly applicable to understanding circuit dysfunction in neurodegenerative diseases and could provide a platform for developing circuit-guided therapeutic interventions,” he said.

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