Swarms of Magnetic Bacteria Could Be Used to Deliver Drugs to Tumors

Swarms of Magnetic Bacteria Could Be Used to Deliver Drugs to Tumors

Researchers funded in part by the National Institute of Biomedical Imaging and Bioengineering (NIBIB) have recently shown that magnetic bacteria are a promising vehicle for more efficiently delivering tumor-fighting drugs. They reported their results in the August 2016 issue of Nature Nanotechnology.

One of the biggest challenges in cancer therapy is being able to sufficiently deliver chemotherapy drugs to tumors without exposing healthy tissues to their toxic effects. One way researchers have attempted to overcome this is by developing nanocarriers — extremely small particles packed with drugs. The nanocarriers are designed so they’re only taken up by cancer cells, thereby preventing the drugs from being absorbed by healthy tissues as they travel through the body’s circulation.

Yet while nanocarriers do a good job protecting healthy tissues, the amount of drug successfully delivered to tumors remains low. The main reasons for this shortcoming are that nanocarriers rely on the circulation system to carry them to the tumor, so a large percentage are filtered out of the body before ever reaching their destination. In addition, differences in pressure between the tumor and its surrounding tissue prevent nanocarriers from penetrating deep inside the tumor. As a result, nanocarriers aren’t able to reach the tumor’s hypoxic zones, which are regions of active cell division that are characterized by low oxygen content.

“Only a very small proportion of drugs reach the hypoxic zones, which are believed to be the source of metastasis. Therefore, targeting the low-oxygen regions will most likely decrease the rate of metastasis while maximizing the effect of a therapy,” says Sylvain Martel, Ph.D., Director of the Polytechnique Montréal NanoRobotics Laboratory and lead researcher of the study.

Martel and his research team were attempting to develop robotic nanocarriers that would travel to hypoxic zones when they realized nature may have already created one in the form of a bacteria called magnetococcus marinus or MC-1. MC-1 cells thrive in deep waters where oxygen is sparse. In order to find these areas, the bacteria rely on a two-part navigation system. The first part involves a chain of magnetic nanocrystals within MC-1 that acts like a compass needle and causes the bacteria to swim in a north direction when in the Northern Hemisphere. The second part consists of sensors that allow the bacteria to detect changes in oxygen levels. This unique navigation system helps the bacteria migrate to and maintain their position at areas of low oxygen.

With funding support from NIBIB and others, Martel’s research team conducted a series of experiments to show that the bacteria’s unique navigation system could be exploited to more efficiently deliver drugs to tumors.

In an initial experiment, mice that had been given human colorectal tumors were injected with either live MC-1 cells, dead MC-1 cells, or as a control group, non-magnetic beads (roughly the same size as the bacteria). The injection was made into the tissue directly adjacent to the tumors after which the mice were exposed to a computer-programmed magnetic field, meant to direct the cells or beads into the tumor. Upon examination of the tumors, the researchers found minimal penetration of the dead bacterial cells and the beads into the tumor, whereas the live bacterial cells were found deep within the tumor and especially in regions with low oxygen content.

“When they get inside the tumor, we switch off the magnetic field and the bacteria automatically rely on the oxygen sensors to seek out the hypoxic areas,” says Martel. “We constrain them to the tumor and then let nature do the rest.”

Next, the researchers wanted to see whether attaching vesicles loaded with drugs to the cells would affect their movement into the tumors. They attached approximately 70 drug-containing vesicles to each bacterial cell. The cells were then injected into another set of mice with colorectal tumors and exposed to the magnet. After examining the tumors of those mice, the researchers estimated that on average, 55% of the injected bacterial cells with attached vesicles made it into the tumor. For comparison, some researchers estimate that only approximately 2% of drugs delivered via current nanocarriers make it into tumors.

“This proof-of-concept work shows the potential to tap into the intricate and optimized cell machinery of single celled organisms such as bacteria,” said Richard Conroy, Ph.D., director of the Division of Applied Sciences and Technology at NIBIB. “The ability to actively and precisely target drug delivery to a tumor will help reduce side effects and potentially improve the efficacy of treatments.”

The next step for Martel’s team is to determine the effects of the drug-loaded bacterial cells on reducing tumor size. They would also like to test whether the bacteria can be used to deliver other types of cancer-killing medicines such as molecules that instruct the immune system to attack tumors.

In addition, the team is working to expand the types of tumors the bacteria could be used for. Currently, the bacteria have to be injected very close to the tumor because, if injected into arteries, the excessive blood flow and the distance needed to travel would impact the number of bacteria that reach the tumor. This limits the drug delivery approach to cancers that are easily accessible such as colorectal, prostate, and potentially breast cancer. However, Martel’s team has shown in animals that they can transport the bacteria through arteries and sufficiently close to the tumor by first encapsulating them in magnetic carriers and propelling them by the magnetic field of an MRI scanner. The bacteria can then be released from the carriers, like torpedoes from a submarine, once close to the tumor. This multi-step approach could potentially open the door for using the bacteria to deliver drugs to tumors deeper in the body.

Martel says that preliminary test results of the bacteria in mice and rats and the fact that the bacteria die within 30 minutes of being injected, suggest that they could potentially be safe in humans.

“These bacteria are really the perfect machine. They replicate, they’re cheap, and we can inject hundreds of millions or more at a time,” says Martel.

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You Can’t Blame Your Genes If You Don’t Lose Weight, Study Finds

You Can’t Blame Your Genes If You Don’t Lose Weight, Study Finds

Carriers of the FTO gene are known to be on average 3 kilos (6.6lbs) heavier and 70% more likely to be obese.

However, researchers at Newcastle University, publishing in The BMJ today, report that in a review of eight studies involving over 9,000 people, carrying this gene did not prevent them losing weight.

John Mathers, Professor of Human Nutrition at Newcastle University, who led the study, said: “You can no longer blame your genes. Our study shows that improving your diet and being more physically active will help you lose weight, regardless of your genetic makeup.”

Getting the weight off

Obesity is a major health problem and, in the UK, more than 25% of adults are obese. For some people, carrying the risk variant of the FTO gene can lead to them being heavier and increasing their risk of obesity. The FTO gene has been shown to have the biggest effect in this area.

In a major collaborative systematic review and meta-analysis, the international team used individual data from 9,563 adults who were enrolled in randomised controlled weight loss trials around the world to find out whether carrying the risk version of the FTO gene affects how much weight people lose.

They found that carrying the risk version of the FTO gene had no effect on weight loss as Professor Mathers explains: “We were excited to find that people with the risk version of FTO respond just as well to weight loss interventions as everyone else.

“This is important news for people trying to lose weight as it means that diet, physical activity or drug-based weight loss plans will work just as well in those who carry the risk version of FTO.

“For public health professionals, it means that the adverse effects of the FTO genotype on weight gain are not an impediment to weight loss interventions.”

FTO gene carriers

lady on scales

Importantly, the team found that the response to weight loss interventions for people carrying the risk variant of the FTO gene was similar for men and women, younger and older and people of different ethnicities.  However, most people in the studies were Caucasians with smaller numbers of those from Black/ African American and Hispanic backgrounds. The team say future research should explore effects of FTO on weight loss in other ethnic groups. In addition, the effects of other obesity-related genes on weight loss remain to be investigated.

In a linked editorial in The BMJ, Dr Alison Tedstone, chief nutritionist at Public Health England, says the causes of the obesity epidemic are multiple and complex, but current evidence suggests they have little to do with gene profiles.

She argues that, if we are to turn back the tide of obesity, a focus on personalised interventions based on the genome “may not pay off, at least in the short term.” Instead, she says “a rebalancing of research towards whole systems approaches including environmental drivers may be of greater benefit to the population in the long term.”

Fungus In Humans Identified For First Time As Key Factor In Crohn’s Disease

Fungus In Humans Identified For First Time As Key Factor In Crohn’s Disease

A Case Western Reserve University School of Medicine-led team of international researchers has for the first time identified a fungus as a key factor in the development of Crohn’s disease. The researchers also linked a new bacterium to the previous bacteria associated with Crohn’s. The groundbreaking findings, published on September 20th in mBio, could lead to potential new treatments and ultimately, cures for the debilitating inflammatory bowel disease, which causes severe abdominal pain, diarrhea, weight loss, and fatigue.

“We already know that bacteria, in addition to genetic and dietary factors, play a major role in causing Crohn’s disease,” said the study’s senior and corresponding author, Mahmoud A Ghannoum, PhD, professor and director of the Center for Medical Mycology at Case Western Reserve and University Hospitals Cleveland Medical Center “Essentially, patients with Crohn’s have abnormal immune responses to these bacteria, which inhabit the intestines of all people. While most researchers focus their investigations on these bacteria, few have examined the role of fungi, which are also present in everyone’s intestines. Our study adds significant new information to understanding why some people develop Crohn’s disease. Equally important, it can result in a new generation of treatments, including medications and probiotics, which hold the potential for making qualitative and quantitative differences in the lives of people suffering from Crohn’s.”

Both bacteria and fungi are microorganisms — infinitesimal forms of life that can only be seen with a microscope. Fungi are eukaryotes: organism whose cells contain a nucleus; they are closer to humans than bacteria, which are prokaryotes: single-celled forms of life with no nucleus. Collectively, the fungal community that inhabits the human body is known as the mycobiome, while the bacteria are called the bacteriome. (Fungi and bacteria are present throughout the body; previously Ghannoum had found that people harbor between nine and 23 fungal species in their mouths.)

The researchers assessed the mycobiome and bacteriome of patients with Crohn’s disease and their Crohn’s-free first degree relatives in nine families in northern France and Belgium, and in Crohn’s-free individuals from four families living in the same geographic area. Specifically, they analyzed fecal samples of 20 Crohn’s and 28 Crohn’s-free patients from nine families and of 21 Crohn’s-free patients of four families. The researchers found strong fungal-bacterial interactions in those with Crohn’s disease: two bacteria (Escherichia coli and Serratia marcescens) and one fungus (Candida tropicalis) moved in lock step. The presence of all three in the sick family members was significantly higher compared to their healthy relatives, suggesting that the bacteria and fungus interact in the intestines. Additionally, test-tube research by the Ghannoum-led team found that the three work together (with the E. coli cells fusing to the fungal cells and S. marcescens forming a bridge connecting the microbes) to produce a biofilm — a thin, slimy layer of microorganisms found in the body that adheres to, among other sites, a portion of the intestines — which can prompt inflammation that results in the symptoms of Crohn’s disease.

This is first time any fungus has been linked to Crohn’s in humans; previously it was only found in mice with the disease. The study is also the first to include S. marcescens in the Crohn’s-linked bacteriome. Additionally, the researchers found that the presence of beneficial bacteria was significantly lower in the Crohn’s patients, corroborating previous research findings.

“Among hundreds of bacterial and fungal species inhabiting the intestines, it is telling that the three we identified were so highly correlated in Crohn’s patients,” said Ghannoum. “Furthermore, we found strong similarities in what may be called the ‘gut profiles’ of the Crohn’s-affected families, which were strikingly different from the Crohn’s-free families. We have to be careful, though, and not solely attribute Crohn’s disease to the bacterial and fungal makeups of our intestines. For example, we know that family members also share diet and environment to significant degrees. Further research is needed to be even more specific in identifying precipitators and contributors of Crohn’s.”

Can Nicotine Protect the Aging Brain?

Can Nicotine Protect the Aging Brain?

Everyone knows that tobacco products are bad for your health, and even the new e-cigarettes may have harmful toxins. However, according to research at Texas A&M, it turns out the nicotine itself—when given independently from tobacco—could help protect the brain as it ages, and even ward off Parkinson’s or Alzheimer’s disease.

Ursula Winzer-Serhan, PhD, an associate professor at the Texas A&M College of Medicine, and her collaborators found that nicotine’s ability to be neuroprotective may be partly due to its well-known ability to suppress the appetite. Their research is published in the Open Access Journal of Toxicology.

Using animal models, Winzer-Serhan and her collaborators added nicotine to the animal’s drinking water. There were three different groups that received nicotine at three different concentrations (low, medium and high) corresponding to occasional, low and medium smokers, respectively, in addition to a control group that did not receive any nicotine.

The two groups that received nicotine at low and medium doses didn’t show any levels of the drug in their blood and they experienced no changes in food intake, body weight or number of receptors in the brain where nicotine acts. In contrast, the group getting the highest concentration of nicotine ate less, gained less weight and had more receptors, indicating that at higher doses, the drug gets into the brain where it can impact behavior. However, even at high doses, it didn’t seem to have worrying behavioral side effects like making the individuals more anxious, which the researchers were concerned could happen.

“Some people say that nicotine decreases anxiety, which is why people smoke, but others say it increases anxiety,” Winzer-Serhan said. “The last thing you would want in a drug that is given chronically would be a negative change in behavior. Luckily, we didn’t find any evidence of anxiety: Only two measures showed any effect even with high levels of nicotine, and if anything, nicotine made animal models less anxious.”

The next step is to test nicotine’s potential anti-aging effects using aged animal models. Although early results indicate that nicotine can keep older individuals from gaining weight like the control group does, Winzer-Serhan hasn’t yet determined whether this lower body mass index translates into less degeneration of the brain. It is also unclear if nicotine’s effects are related only to its ability to suppress appetite, or if there are more mechanisms at work.

Because there are still so many unknowns, Winzer-Serhan urges caution. “I want to make it very clear that we’re not encouraging people to smoke,” she said. “Even if these weren’t very preliminary results, smoking results in so many health problems that any possible benefit of the nicotine would be more than cancelled out. However, smoking is only one possible route of administration of the drug, and our work shows that we shouldn’t write-off nicotine completely.”

Still, Winzer-Serhan cautions people not to purchase nicotine-containing products just yet. “Although the results are intriguing, we would need large-scale clinical trials before suggesting anyone change their behavior,” she said. “At the end of the day, we haven’t proven that this addictive drug is safe—and it certainly isn’t during childhood or adolescence—or that the benefits outweigh the potential risks.”

NASA Scientists Find ‘Impossible’ Cloud on Titan — Again

NASA Scientists Find ‘Impossible’ Cloud on Titan — Again

The puzzling appearance of an ice cloud seemingly out of thin air has prompted NASA scientists to suggest that a different process than previously thought — possibly similar to one seen over Earth’s poles — could be forming clouds on Saturn’s moon Titan.

Located in Titan’s stratosphere, the cloud is made of a compound of carbon and nitrogen known as dicyanoacetylene (C4N2), an ingredient in the chemical cocktail that colors the giant moon’s hazy, brownish-orange atmosphere.

Decades ago, the infrared instrument on NASA’s Voyager 1 spacecraft spotted an ice cloud just like this one on Titan. What has puzzled scientists ever since is this: they detected less than 1 percent of the dicyanoacetylene gas needed for the cloud to condense.

Recent observations from NASA’s Cassini mission yielded a similar result. Using Cassini’s composite infrared spectrometer, or CIRS — which can identify the spectral fingerprints of individual chemicals in the atmospheric brew — researchers found a large, high-altitude cloud made of the same frozen chemical. Yet, just as Voyager found, when it comes to the vapor form of this chemical, CIRS reported that Titan’s stratosphere is as dry as a desert.

“The appearance of this ice cloud goes against everything we know about the way clouds form on Titan,” said Carrie Anderson, a CIRS co-investigator at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study.

The typical process for forming clouds involves condensation. On Earth, we’re familiar with the cycle of evaporation and condensation of water. The same kind of cycle takes place in Titan’s troposphere — the weather-forming layer of Titan’s atmosphere — but with methane instead of water.

A different condensation process takes place in the stratosphere — the region above the troposphere — at Titan’s north and south winter poles. In this case, layers of clouds condense as the global circulation pattern forces warm gases downward at the pole. The gases then condense as they sink through cooler and cooler layers of the polar stratosphere.

NASA Scientists Find ‘Impossible’ Cloud on Titan — Again This graphic illustrates how scientists think This graphic illustrates how scientists think “solid state” chemistry may be taking place in ice particles that form clouds in the atmosphere of Saturn’s moon Titan. Image credit: NASA/JPL-Caltech/GSFC.

Either way, a cloud forms when the air temperature and pressure are favorable for the vapor to condense into ice. The vapor and the ice reach a balance point — an equilibrium — that is determined by the air temperature and pressure. Because of this equilibrium, scientists can calculate the amount of vapor where ice is present.

“For clouds that condense, this equilibrium is mandatory, like the law of gravity,” said Robert Samuelson, an emeritus scientist at Goddard and a co-author of the paper.

But the numbers don’t compute for the cloud made from dicyanoacetylene. The scientists determined that they would need at least 100 times more vapor to form an ice cloud where the cloud top was observed by Cassini’s CIRS.

One explanation suggested early on was that the vapor might be present, but Voyager’s instrument wasn’t sensitive enough in the critical wavelength range needed to detect it. But when CIRS also didn’t find the vapor, Anderson and her Goddard and Caltech colleagues proposed an altogether different explanation. Instead of the cloud forming by condensation, they think the C4N2 ice forms because of reactions taking place on other kinds of ice particles. The researchers call this “solid-state chemistry,” because the reactions involve the ice, or solid, form of the chemical.

The first step in the proposed process is the formation of ice particles made from the related chemical cyanoacetylene (HC3N). As these tiny bits of ice move downward through Titan’s stratosphere, they get coated by hydrogen cyanide (HCN). At this stage, the ice particle has a core and a shell comprised of two different chemicals. Occasionally, a photon of ultraviolet light tunnels into the frozen shell and triggers a series of chemical reactions in the ice. These reactions could begin either in the core or within the shell. Both pathways can yield dicyanoacteylene ice and hydrogen as products.

The researchers got the idea of solid-state chemistry from the formation of clouds involved in ozone depletion high above Earth’s poles. Although Earth’s stratosphere has scant moisture, wispy nacreous clouds (also called polar stratospheric clouds) can form under the right conditions. In these clouds, chlorine-bearing chemicals that have entered the atmosphere as pollution stick to crystals of water ice, resulting in chemical reactions that release ozone-destroying chlorine molecules.

“It’s very exciting to think that we may have found examples of similar solid-state chemical processes on both Titan and Earth,” said Anderson.

The researchers suggest that, on Titan, the reactions occur inside the ice particles, sequestered from the atmosphere. In that case, dicyanoacetylene ice wouldn’t make direct contact with the atmosphere, which would explain why the ice and the vapor forms are not in the expected equilibrium.

“The compositions of the polar stratospheres of Titan and Earth could not differ more,” said Michael Flasar, CIRS principal investigator at Goddard. “It is amazing to see how well the underlying physics of both atmospheres has led to analogous cloud chemistry.”

The findings are published in the journal Geophysical Research Letters.

New Record: Quantum Teleportation of a Particle of Light Six Kilometers

New Record: Quantum Teleportation of a Particle of Light Six Kilometers

Through a collaboration between the University of Calgary, The City of Calgary and researchers in the United States, a group of physicists led by Wolfgang Tittel, professor in the Department of Physics and Astronomy at the University of Calgary have successfully demonstrated teleportation of a photon (an elementary particle of light) over a straight-line distance of six kilometres using The City of Calgary’s fibre optic cable infrastructure. The project began with an Urban Alliance seed grant in 2014.

This accomplishment, which set a new record for distance of transferring a quantum state by teleportation, has landed the researchers a spot in the prestigious Nature Photonics scientific journal. The finding was published back-to-back with a similar demonstration by a group of Chinese researchers.

“Such a network will enable secure communication without having to worry about eavesdropping, and allow distant quantum computers to connect,” says Tittel.

Experiment draws on ‘spooky action at a distance’

The experiment is based on the entanglement property of quantum mechanics, also known as “spooky action at a distance” — a property so mysterious that not even Einstein could come to terms with it.

“Being entangled means that the two photons that form an entangled pair have properties that are linked regardless of how far the two are separated,” explains Tittel. “When one of the photons was sent over to City Hall, it remained entangled with the photon that stayed at the University of Calgary.”

Next, the photon whose state was teleported to the university was generated in a third location in Calgary and then also travelled to City Hall where it met the photon that was part of the entangled pair.

“What happened is the instantaneous and disembodied transfer of the photon’s quantum state onto the remaining photon of the entangled pair, which is the one that remained six kilometres away at the university,” says Tittel.

City’s accessible dark fibre makes research possible

The research could not be possible without access to the proper technology. One of the critical pieces of infrastructure that support quantum networking is accessible dark fibre. Dark fibre, so named because of its composition — a single optical cable with no electronics or network equipment on the alignment — doesn’t interfere with quantum technology.

The City of Calgary is building and provisioning dark fibre to enable next-generation municipal services today and for the future.

Wolfgang Tittel, professor in the Department of Physics and Astronomy at the University of Calgary. Photo by Riley Brandt, University of Calgary
Wolfgang Tittel, professor in the Department of Physics and Astronomy at the University of Calgary. Photo by Riley Brandt, University of Calgary.

“By opening The City’s dark fibre infrastructure to the private and public sector, non-profit companies, and academia, we help enable the development of projects like quantum encryption and create opportunities for further research, innovation and economic growth in Calgary,” said Tyler Andruschak, project manager with Innovation and Collaboration at The City of Calgary.

“The university receives secure access to a small portion of our fibre optic infrastructure and The City may benefit in the future by leveraging the secure encryption keys generated out of the lab’s research to protect our critical infrastructure,” said Andruschak. In order to deliver next-generation services to Calgarians, The City has been increasing its fibre optic footprint, connecting all City buildings, facilities and assets.

Timed to within one millionth of one millionth of a second

As if teleporting a photon wasn’t challenging enough, Tittel and his team encountered a number of other roadblocks along the way.

Due to changes in the outdoor temperature, the transmission time of photons from their creation point to City Hall varied over the course of a day — the time it took the researchers to gather sufficient data to support their claim. This change meant that the two photons would not meet at City Hall.

“The challenge was to keep the photons’ arrival time synchronized to within 10 pico-seconds,” says Tittel. “That is one trillionth, or one millionth of one millionth of a second.”

Secondly, parts of their lab had to be moved to two locations in the city, which as Tittel explains was particularly tricky for the measurement station at City Hall which included state-of-the-art superconducting single-photon detectors developed by the National Institute for Standards and Technology, and NASA’s Jet Propulsion Laboratory.

“Since these detectors only work at temperatures less than one degree above absolute zero the equipment also included a compact cryostat,” said Tittel.

Milestone towards a global quantum Internet

This demonstration is arguably one of the most striking manifestations of a puzzling prediction of quantum mechanics, but it also opens the path to building a future quantum internet, the long-term goal of the Tittel group.

New Ways to Track Stars Eaten by Black Holes

New Ways to Track Stars Eaten by Black Holes

Research led by Johns Hopkins University astrophysicists using information from a NASA space telescope breaks new ground in ways to observe a star swallowed by a black hole, promising to help paint a clearer picture of this cosmic phenomenon.

The results, published online in the Astrophysical Journal, are based on two methods that are new in the study of this sort of star destruction: the first infrared observations, and using galaxy dust to reflect, or “echo,” the electromagnetic energy burst of a star being devoured by a black hole, called a “tidal disruption flare.”

The approach, which in this case allowed scientists to measure flare energy more precisely than had been done before, offers fresh ways to understand “tidal disruptions.” The phenomena were first raised hypothetically in the 1970s, and only studied closely since 2005, although the first possible examples were claimed several years earlier, said Julian H. Krolik, a professor in the Department of Physics and Astronomy at Johns Hopkins and one of four authors of the paper.

“What happens to the mass of the star once it’s torn apart?” Krolik said. “Is it heated up? Does it go quickly into the black hole? Does it swirl around for a while? These are the questions” that this approach could help to answer, Krolik said. He co-wrote the paper with lead author Sjoert van Velzen, a Hubble Fellow at Johns Hopkins; Alexander J. Mendez, who was a post-doctoral fellow at the university when the work was done; and Varoujan Gorjian, an astronomer at NASA’s Jet Propulsion Laboratory, a division of Caltech.

The four scientists used images that had been compiled by the Wide-field Infrared Survey Explorer (WISE) telescope, which NASA launched into Earth’s orbit in 2009. The study considered five instances in which a star had apparently moved close enough to the gravitational pull of a black hole to be drawn in, have its mass stretched and compressed into long strands, and be devoured — a “tidal disruption.”

The events — each of which can unfold over a period of months — occurred in five galaxies, the closest of which is 840 million light years from Earth.

In each case, the destruction of the star set off a burst of energy, or flare. Krolik said it’s been generally expected that the flares would emit most of their energy in low-energy X-rays or extreme ultraviolet light, but these bands are very difficult to observe. For that reason, most observations have been in visible or near ultraviolet light.

This research relied on indirect observation of the flare. The scientists compiled information gathered by the telescope on the temperature of the dust roughly 2 trillion miles away from where the stars were destroyed by the black holes. The intense radiation of the flare first burns away the dust, cleaning out a sphere with a radius of about 2 trillion miles. At the edge of this sphere, dust absorbs and then re-emits the heat from the tidal disruption flare, creating a thermal “echo” picked up by the telescope.

“The dust echo thus provides a unique means to measure total energy that is emitted during the stars’ destruction,” van Velzen said. “A measurement of the total energy is very important; without this we have an incomplete picture of what happens during a stellar tidal disruption. For example, the total energy is needed to understand if the star got fully destroyed, or if the black hole only nibbled a piece of the star.”

The study refined the understanding of the energy produced by these flares. The flare energy was measured at 10 times more than previous observations saw, but one tenth the energy predicted in the earliest, most simple models.

That point is part of an emerging understanding of a cosmic event that has only been observed a few dozen times. The picture is bound to become clearer as researchers develop new methods, including the first infrared observations.

“In astronomy, opening a ‘new wavelength regime’ is often reason to celebrate,” van Velzen said.

The research says “there’s value in the use of infrared telescopes in looking for these echoes,” added Krolik. “We expect to do more.”