Articles from October 2022

Gel-like Implant Destroys Pancreatic Cancer

Biomedical engineers at Duke University have demonstrated the most effective treatment for pancreatic cancer ever recorded in mouse models. While most mouse trials consider simply halting growth a success, the new treatment completely eliminated tumors in 80 percent of mice across several model types, including those considered the most difficult to treat.

The approach combines traditional chemotherapy drugs with a new method for irradiating the tumor. Rather than delivering radiation from an external beam that travels through healthy tissue, the treatment implants radioactive iodine-131 directly into the tumor within a gel-like depot that protects healthy tissue and is absorbed by the body after the radiation fades away.

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New Plastic Conducts Electricity Like Metal

Scientists with the University of Chicago have discovered a way to create a material that can be made like a plastic, but conducts electricity more like a metal. The research, published Oct. 26 in Nature, shows how to make a kind of material in which the molecular fragments are jumbled and disordered, but can still conduct electricity extremely well.

This goes against all of the rules we know about for conductivity—to a scientist, it’s kind of seeing a car driving on water and still going 70 mph. But the finding could also be extraordinarily useful; if you want to invent something revolutionary, the process often first starts with discovering a completely new material.

In principle, this opens up the design of a whole new class of materials that conduct electricity, are easy to shape, and are very robust in everyday conditions,” said John Anderson, an associate professor of chemistry at the University of Chicago and the senior author on the study. “Essentially, it suggests new possibilities for an extremely important technological group of materials,” said Jiaze Xie (PhD’22, now at Princeton), the first author on the paper.

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Gel Treats Gum Disease by Fighting Inflammation

A topical gel that blocks the receptor for a metabolic byproduct called succinate treats gum disease by suppressing inflammation and changing the makeup of bacteria in the mouth, according to a new study led by researchers at NYU College of Dentistry and published in Cell ReportsThe research, conducted in mice and using human cells and plaque samples, lays the groundwork for a non-invasive treatment for gum disease that people could apply to the gums at home to prevent or treat gum disease.

Gum disease (also known as periodontitis or periodontal disease) is one of the most prevalent inflammatory diseases, affecting nearly half of adults 30 and older. It is marked by three components: inflammation, an imbalance of unhealthy and healthy bacteria in the mouth, and destruction of the bones and structures that support the teeth. Uncontrolled gum disease can lead to painful and bleeding gums, difficulty chewing, and tooth loss.

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How to Grow Fully Functioning Hair Follicles

We can add functional mouse hair follicles to body parts that scientists have successfully grown in the lab, outside the body. Using cells obtained from embryonic mice, for the first time researchers were able to produce hair follicle organoidssmall, simple versions of an organ – that grew hair.

Moreover, they were able to influence the pigmentation of the hair; and, when the follicles were transplanted into living hairless mice, they continued to function across multiple hair growth cycles. This research, the team says, could help aid efforts to treat hair loss, as well as provide alternative models to animal testing and drug screening.

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How to Boost DNA Repair in Aging Cells

Scientists have long wondered why cells lose their ability to repair themselves as they age. New research by scientists has uncovered two intriguing cluesDNA strands in human cells routinely break and repair themselves, Seluanov and Gorbunova from University of Rochester explained, but as cells age, the system for repair becomes less efficient and flaws in the process lead to a decline in the functionality of tissue and an increase in the incidence of tumors. Their team wanted to determine why this occurs, and establish whether the process could be slowed, or even reversed.
Seluanov and his colleagues found that the decline in a cell's ability to repair DNA during aging coincided with a global reduction in the levels of proteins involved in the repair process. Seluanov's group tried to reverse the age-related decline in DNA repair efficiency by restoring the proteins to their original levels and found only one protein, SIRT6, did the trick. Gorbunova said the results build on a paper by Haim Cohen, a staff scientist investigating aging at Bar-Ilan University in Israel, and others published in the journal Nature this summer.

"That work showed that overexpressing the SIRT6 protein extended the lifespans of mice," said Gorbunova, "Our research looked at DNA repair and found a reason for the increased longevity, and that is SIRT6's role in promoting more efficient DNA repair."

The next step for Seluanov and his team is to study the factors that regulate SIRT6, in an effort to learn more about the early stages of the DNA repair process. Seluanov said that multiple groups are trying to develop drugs that activate SIRT6, and he hopes that this research will one day lead to therapies that help extend a person's lifespan and treat cancer.

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Wireless Implant Could Help Remove Deadly Brain Tumors

Brain tumors are among the most deadly and difficult-to-treat cancers. Glioblastoma, a particularly aggressive form, kills more than 10,000 Americans a year and has a median survival time of less than 15 months. For patients with brain tumors, treatment typically includes open-skull surgery to remove as much of the tumor as possible followed by chemotherapy or radiation, which come with serious side effects and numerous hospital visits.

What if a patient’s brain tumor could be treated painlessly, without anesthesia, in the comfort of their home? Researchers at Stanford Medicine have developed, and tested in mice, a small wireless device that one day could do just that. The device is a remotely activated implant that can heat up nanoparticles injected into the tumor, gradually killing cancerous cells. In mice with brain tumors, 15 minutes of daily treatment over 15 days, as the animals went about their normal activities, was enough to significantly increase survival times. The researchers published their work in August in Nature Nanotechnology.

The nanoparticles help us target the treatment to only the tumor, so the side effects will be relatively less compared with chemotherapy and radiation,” said Hamed Arami, PhD, co-lead  author of the paper, a former postdoctoral fellow at Stanford Medicine who is now at Arizona State University.

Arami, trained as a bioengineer, came to focus on brain cancer as a postdoctoral fellow in the lab of the late Sam Gambhir, MD, former chair of radiology at Stanford Medicine and a pioneer in molecular imaging and cancer diagnostics who died of cancer in 2020 . Five years prior, Gambhir’s teenage son, Milan, died of a glioblastoma.


Photonic Chip Transmits All of the Internet’s Traffic Every Second

An international group of researchers from Technical University of Denmark (DTU) and Chalmers University of Technology in Gothenburg, Sweden have achieved dizzying data transmission speeds and are the first in the world to transmit more than 1 petabit per second (Pbit/s) using only a single laser and a single optical chip1 petabit corresponds to 1 million gigabits.

In the experiment, the researchers succeeded in transmitting 1.8 Pbit/s, which corresponds to twice the total global Internet traffic. And only carried by the light from one optical source. The light source is a custom-designed optical chip, which can use the light from a single infrared laser to create a rainbow spectrum of many colours, i.e. many frequencies. Thus, the one frequency (colour) of a single laser can be multiplied into hundreds of frequencies (colours) in a single chip.

All the colours are fixed at a specific frequency distance from each other – just like the teeth on a comb – which is why it is called a frequency comb. Each colour (or frequency) can then be isolated and used to imprint data. The frequencies can then be reassembled and sent over an optical fibre, thus transmitting data. Even a huge volume of data, as the researchers have discovered.

The experimental demonstration showed that a single chip could easily carry 1.8 Pbit/s, which—with contemporary state-of-the-art commercial equipment—would otherwise require more than 1,000 lasers. Victor Torres Company, professor at Chalmers University of Technology, is head of the research group that has developed and manufactured the chip.

What is special about this chip is that it produces a frequency comb with ideal characteristics for fiber-optical communications – it has high optical power and covers a broad bandwidth within the spectral region that is interesting for advanced optical communications,” says Victor Torres Company.

Interestingly enough, the chip was not optimized for this particular application. “In fact, some of the characteristic parameters were achieved by coincidence and not by design,” adds Victor Torres Company. “However, with efforts in my team, we are now capable to reverse engineer the process and achieve with high reproducibility microcombs for target applications in telecommunications.

In addition, the researchers created a computational model to examine theoretically the fundamental potential for data transmission with a single chip identical to the one used in the experiment. The calculations showed enormous potential for scaling up the solution.

Professor Leif Katsuo Oxenløwe, Head of the Centre of Excellence for Silicon Photonics for Optical Communications (SPOC) at DTU, explains:

Our calculations show that—with the single chip made by Chalmers University of Technology, and a single laser—we will be able to transmit up to 100 Pbit/s. The reason for this is that our solution is scalable—both in terms of creating many frequencies and in terms of splitting the frequency comb into many spatial copies and then optically amplifying them, and using them as parallel sources with which we can transmit data. Although the comb copies must be amplified, we do not lose the qualities of the comb, which we utilize for spectrally efficient data transmission.”


Cheap High Performance Li-ion Batteries

Li-ion batteries (LIBs) are one of the most used batteries that support modern ITC society, including smartphones and EVs. LIBs are repeatedly charged and discharged by Li-ions passing back and forth between the positive and negative electrodes, with the Li-ion electrolyte acting as a passageway for the ions.

Normally, organic electrolytes such as liquid ethylene carbonate (EC) and their gels have been used as the Li-ion electrolyte due to their voltage resistance and ionic conductivity. However, as liquids and gels are flammable, a switch to safer polymeric solid electrolytes is preferable.

Polymeric solid electrolytes such as polyethylene glycol (PEG) have been proposed as impact-resistant Li-ion electrolytes. However, PEG-based polymer electrolytes crystallize near room temperature, resulting in a significant drop in Li-ion conductivity to around 10-6 S/cm at room temperature. To solve this problem, a research group has invented a new type of polymeric solid electrolyte by combining a porous polymer membrane with several micron pores and a photo-cross-linkable polyethylene glycol PEG-based polymer electrolyte.

This polymeric solid electrolyte not only shows high performance as an electrolyte but is also expected to be effective in deterring the formation of Li dendrites (dendritic crystals), which can cause ignition, due to the inclusion of a porous membrane. Through the realization of safe, high-performance LIBs, this achievement will contribute to the realization of a sustainable energy supply, which is the seventh goal of the SDGs.


Personalized Skin Cancer Vaccine

Two major pharmaceutical companies are testing a personalized vaccine that might prevent the recurrence of a specific type of skin cancer. Moderna, one of the companies behind the COVID-19 vaccine, and Merck, an enterprise focused largely on oncology and preventative medicines, are teaming up to see if they can reduce the public’s risk of re-developing the deadliest form of skin cancer: melanoma.

The vaccine essentially combines two medical technologies: the mRNA vaccine and Merck’s Keytruda. As with the COVID-19 vaccine, mRNA shots don’t require an actual virus. Instead, they use a disease’s genetic code to “teach” the immune system to recognize and fight that particular illness. This makes it relatively easy and inexpensive for scientists to develop mRNA vaccines and edit them if a new form of the disease emerges. Keytruda, meanwhile, is a prescription medication that helps prevent melanoma from coming back after known cancer cells have been surgically removed.

Moderna and Merck are testing the feasibility of not only creating a two-in-one drug with both technologies but also customizing individual vaccines to suit their respective patients. Each vaccine is engineered to activate the patient’s immune system, which in turn deploys T cells (a type of white blood cell known to fight cancer) that go after the specific mutations of a patient’s tumor. Keytruda assists this effort by barring certain cell proteins from getting in the way of T cells’ intervention.

The experimental drug is currently in its second clinical trial out of three. The trial involves 157 participants with high-risk melanoma who just successfully underwent surgical removal. Some of the participants were given the personalized vaccine, while others were given Keytruda alone. Moderna and Merck will observe whether the participants’ melanoma returns over the span of approximately one year, with primary data expected at the end of this year.

If a vaccine preventing the recurrence of melanoma does in fact become commercially available, it could prevent more than 7,000 deaths per year in the US alone.


Fabric Heats Up and Cools Down its Wearer

Textile engineers have developed a fabric woven out of ultra-fine nano-threads made in part of phase-change materials and other advanced substances that combine to produce a fabric that can respond to changing temperatures to heat up and cool down its wearer depending on need. The material that can store and release large amounts of heat when the material changes phase from liquid to solid. Combining the threads with electrothermal and photothermal coatings that enhance the effect, they have in essence developed a fabric that can both quickly cool the wearer down and warm them up as conditions change.

Such fabrics often make use of phase-change materials (PCMs) that can store and later release large amounts of heat when the material changes phase (or state of matter, for example, from solid to liquid). One such material is paraffin, which can in principle be incorporated into a textile material in different ways. When the temperature of the environment around the paraffin reaches its melting point, its physical state changes from solid to liquid, which involves an absorption of heat. Then heat is released when the temperature reaches paraffin’s freezing point.


The problem here has been that the manufacturing methods for phase-change micro-capsules are complex and very costly,” said Hideaki Morikawa, corresponding author of the paper and an advanced textiles engineer with the Institute for Fiber Engineering at Shinshu University. “Worse still, this option offers insufficient flexibility for any realistically wearable application.”

So the researchers turned to an option called coaxial electrospinning. Electrospinning is a method of manufacturing extremely fine fibers with diameters on the order of nanometers. When a polymer solution contained in a bulk reservoir, typically a syringe tipped with a needle, is connected to a high-voltage power source, electric charge accumulates on the surface of the liquid.

A paper describing the manufacturing technique appeared in the American Chemical Society journal ACSNano.