A team of researchers at MIT and in China has developed a new solar-powered desalination system that is both more efficient and less expensive than previous solar desalination methods. The process could be used to treat contaminated wastewater or to generate steam for sterilizing medical instruments, all without requiring any power source other than sunlight itself.
Many attempts at solar desalination systems rely on some kind of wick to draw the saline water through the device, but these wicks are vulnerable to salt accumulation and relatively difficult to clean. The MIT team focused on developing a wick-free system instead.
The system is comprised of several layers with dark material at the top to absorb the sun’s heat, then a thin layer of water above a perforated layer of material, sitting atop a deep reservoir of the salty water such as a tank or a pond. The researchers determined the optimal size for the holes drilled through the perforated material, which in their tests was made of polyurethane. At 2.5 millimeters across, these holes can be easily made using commonly available waterjets.
In this schematic, a confined water layer above the floating thermal insulation enables the simultaneous thermal localization and salt rejection. Credit: MIT
With the help of dark material, the thin layer of water is heated until it evaporates, which can then be condensed onto a sloped surface for collection as pure water. The holes in the perforated material are large enough to allow for a natural convective circulation between the warmer upper layer of water and the colder reservoir below. That circulation naturally draws the salt from the thin layer above down into the much larger body of water below, where it becomes well-diluted and no longer a problem.
During the experiments, the team says their new technique achieved over 80% efficiency in converting solar energy to water vapor and salt concentrations up to 20% by weight. Their test apparatus operated for a week with no signs of any salt accumulation.
Researchers test two identical outdoor experimental setups placed next to each other. Credit: MIT
So far, the team has proven the concept using small benchtop devices, so the next step will be starting to scale up to devices that could have practical applications. According to the researchers, their system with just 1 square meter (about a square yard) of collecting area should be sufficient to provide a family’s daily needs for drinking water. They calculated that the necessary materials for a 1-square-meter device would cost only about $4.
The team says the first applications are likely to be providing safe water in remote off-grid locations or for disaster relief after hurricanes, earthquakes, or other disruptions of normal water supplies. MIT graduate student Lenan Zhang adds that“if we can concentrate the sunlight a little bit, we could use this passive device to generate high-temperature steam to do medical sterilization” for off-grid rural areas.
Lithium extraction. Credit: The University of Texas at Austin.
Anyone using a cellphone, laptop or electric vehicle depends on lithium. The element is in tremendous demand. And although the supply of lithium around the world is plentiful, getting access to it and extracting it remains a challenging and inefficient process.
An interdisciplinary team of engineers and scientists is developing a way to extract lithium from contaminated water. New research, published this week in Proceedings of the National Academies of Sciences, could simplify the process of extracting lithium from aqueous brines, potentially create a much larger supply and reduce costs of the element for batteries to power electric vehicles, electronics and a wide range of other devices. Currently, lithium is most commonly sourced from salt brines in South America using solar evaporation, a costly process that can take years and loses much of the lithium along the way.
The research team from The University of Texas at Austin and University of California, Santa Barbara designed membranes for precise separation of lithium over other ions, such as sodium, significantly improving the efficiency of gathering the coveted element.
“The study’s findings have significant implications for addressing major resource constraints for lithium, with the potential to also extract it from water generated in oil and gas production for batteries,” said Benny Freeman, a professor in the McKetta Department of Chemical Engineering at UT Austin and a co-author on the paper.
Beyond salt brines, wastewater generated in oil and gas production also contains lithium but remains untapped today. Just a single week’s worth of water from hydraulic fracturing in Texas’s Eagle Ford Shale has the potential to produce enough lithium for 300 electric vehicle batteries or 1.7 million smartphones, the researchers said. This example shows the scale of opportunities for this new technique to vastly increase lithium supply and lower costs for devices that rely on it.
At the heart of the discovery is a novel polymer membrane the researchers created using crown ethers, which are ligands with specific chemical functionality to bind certain ions. Crown ethers had not previously been applied or studied as integral parts of water treatment membranes, but they can target specific molecules in water—a key ingredient for lithium extraction.
In most polymers, sodium travels through membranes faster than lithium. However, in these new materials, lithium travels faster than sodium, which is a common contaminant in lithium-containing brines. Through computer modeling, the team discovered why this was happening. Sodium ions bind with the crown ethers, slowing them down, while lithium ions remain unbound, enabling them to move more quickly through the polymer.
The findings represent a new frontier in membrane science that required above-and-beyond collaboration between the universities in such areas as polymer synthesis, membrane characterization and modeling simulation. The research was supported as part of the Center for Materials for Water and Energy Systems, an Energy Frontier Research Center at UT Austin funded by the U.S. Department of Energy.
The lead authors of the paper are Samuel J. Warnock of UCSB’s Materials Department and Rahul Sujanani and Everett S. Zofchak from the McKetta Department of Chemical Engineering at UT Austin. Other contributors are, from UT Austin, professors Venkat Ganesan and Freeman and researchers Theodore J. Dilenschneider; and from UCSB, Chemical Engineering assistant professor Chris Bates, Chemistry professor Mahdi Abu-Omar, and researchers Kalin G. Hanson, Shou Zhao and Sanjoy Mukherjee.
The term ‘DNA’ immediately calls to mind the double-stranded helix that contains all our genetic information. But the individual units of its two strands are pairs of molecules bonded with each other in a selective, complementary fashion. Turns out, one can take advantage of this pairing property to perform complex mathematical calculations, and this forms the basis of DNA nanotechnology and DNA computing.
Since DNA has only two strands, performing even a simple calculation requires multiple chemical reactions using different sets of DNA. In most existing research, the DNA for each reaction are added manually, one by one, into a single reaction tube, which makes the process very cumbersome.
Microfluidic chips, which consist of narrow channels etched onto a material like plastic, offer a way to automate the process. But despite their promise, the use of microfluidic chips for DNA computing remains underexplored.
In a recent article in ACS Nano (“Programmable DNA-Based Boolean Logic Microfluidic Processing Unit”), a team of scientists from Incheon National University (INU), Korea, present a programmable DNA-based microfluidic chip that can be controlled by a personal computer to perform DNA calculations.
“Our hope is that DNA-based CPUs will replace electronic CPUs in the future because they consume less power, which will help with global warming. DNA-based CPUs also provide a platform for complex calculations like deep learning solutions and mathematical modelling,” says Dr. Youngjun Song from INU, who led the study.
Dr. Song and team used 3D printing to fabricate their microfluidic chip, which can execute Boolean logic, one of the fundamental logics of computer programming. Boolean logic is a type of true-or-false logic that compares inputs and returns a value of ‘true’ or ‘false’ depending on the type of operation, or ‘logic gate,’ used. The logic gate in this experiment consisted of a single-stranded DNA template.
Different single-stranded DNA were then used as inputs. If part of an input DNA had a complementary Watson-Crick sequence to the template DNA, it paired to form double-stranded DNA. The output was considered true or false based on the size of the final DNA.
What makes the designed chip extraordinary is a motor-operated valve system that can be operated using a PC or smartphone. The chip and software set-up together form a microfluidic processing unit (MPU). Thanks to the valve system, the MPU could perform a series of reactions to execute a combination of logic operations in a rapid and convenient manner.
This unique valve system of the programmable DNA-based MPU paves the way for more complex cascades of reactions that can code for extended functions. “Future research will focus on a total DNA computing solution with DNA algorithms and DNA storage systems,” says Dr. Song.
In the past two years, companies have promised electric motors producing far more torque density, measured in kilowatts per kilogram. Avid said its Evo Axial Flux motor makes “one of the highest usable power and torque densities of any electric vehicle motor available on the market today.” Equipmake says its motors develop “class leading power densities.” Yasa claims its “electric motors … provide the highest power/torque density available in their category.”
Enter Linear Labs, which says it has a motor to beat all. The company declares its Hunstable Electric Turbine (HET), perhaps with unintentional shades of Ayn Rand, “The Motor of the World.”
Watch The Video
The company told Autoblog, “The defining characteristic of this motor [is that] at very low RPMs … [for] the same size, same weight, same volume, and the same amount of input energy into the motor, we will always produce – at a minimum, sometimes more, but at a minimum – two to three times the torque output of any electric motor in the world, and it does this at high efficiency throughout the torque and speed range.”
“Hunstable” comes from the two principals: Fred Hunstable, an engineer who spent years designing the electrical infrastructure for nuclear power plants in the United States; and Brad Hunstable, Fred’s son and an ex-tech entrepreneur who helped found the streaming service Ustream, sold to IBM in 2016 for $150 million.
Linear Labs began as a father-son project to create a linear generator surrounding the shaft of an old-fashioned windmill that would provide reliable power (as well as clean water) to impoverished communities. The challenge was designing a generator able to produce sufficient power from the shaft’s low-speed, high-torque reciprocating movement. Brad said his father cracked the code about four years ago, resulting in “a linear generator that produced massive amounts of electricity from a slow-moving windmill.” What’s more, the breakthrough was modular, leading to a family of motors that has been issued 25 patents so far.
What is the Hunstable Electric Turbine?
Electric motors are well into their second century, having barely changed since Nikola Tesla patented his innovations with the modern three-phase, four-pole induction motor between 1886 and 1889. While all motors consist of similar fundamental components – copper wire coils known as windings, and magnets – the way in which those components interact is slightly different. In a radial flux motor, one component spins within the other – imagine a small can spinning inside a larger stationary one. In an axial flux design, the components spin next to each other, like two flywheels sandwiching a central, stationary plate.
Typically, the way to create more torque is to send more current into a motor or build a larger motor. Linear Labs has found another way: by combining axial and radial flux designs in a single motor.
Images: Stators and Rotors
Copper Windings Inside the Huntstable Electric Turbine: Illustrations by Linear Labs
The HET is four rotors surrounding a stator. A central rotor spins inside a stator, creating one source of flux. A second rotor spins outside the stator, creating a second source of flux. Two additional rotors lie at the left and right ends of the stator, essentially forming an AF motor. That’s two more sources of flux, making four in total. It’s essentially two concentric radial motors bookended by two axial ones.
Linear Labs says all the HET generates all torque in the direction of rotor motion. In a promotional video, Fred Hunstable said, “We call it circumferential flux, sort of like a torque tunnel.”
Generating more torque in a given volume, and having all of that torque move in the direction of rotor motion, is how the Hunstables claim, “two to three times the torque for that size envelope compared to any other motor out there. It doesn’t matter what kind [of motor] it is, we will always out-produce it.”
Furthermore, by using discrete rectangular coils inset into the stator poles, the HET needs 30% less copper than a motor of similar size. The design also eliminates end windings – lengths of copper that lie outside the stator in a typical motor, generating wasted magnetic field and heat.
Illustration by Linear Labs
What the HET could mean for future electric cars
So far, Linear Labs has inked deals with a scooter maker, with Swedish electric drive system firm Abtery, and with an unnamed firm designing a hypercar to be released within two years, utilizing four HETs. However, Brad Hunstable thinks the HET could have applications in the electric vehicle space, since the HET’s torque comes at RPMs that match the end use. Current EV motors spin much faster than the wheels, so most EVs use a reduction gear to connect a motor spinning at several thousand RPM with wheels spinning at anywhere from one to perhaps 1,800 RPM. If the HET generates the necessary torque at RPMs that match wheel speed, a carmaker could theoretically discard the reduction gear, reducing weight and improving powertrain efficiency.
Brad said testing has shown the HET in direct-drive configuration works in applications normally served by a 6:1 reduction gearbox, and it’s possible that the ratio is even higher. The downstream effects could be significant, according to Hunstable. That weight savings – the lower operating speed of the HET means fewer and lighter electronics, the company says – and efficiency gain could be used to reduce the size of the battery and thus the weight of the vehicle, saving cash and letting the manufacturer use lighter-duty components – perhaps enough to make a significant difference to the bottom line, Hunstable thinks.
The HET can also take over the role of a component known as a DC/DC boost converter, used in some EVs in situations in which the vehicle needs to trade torque for horsepower, such as during hard acceleration at highway speeds. By doing so, they use additional energy that can’t be put towards range. In general terms, EVs that emphasize performance use a boost converter, like the Tesla Model S, while ones that emphasize efficiency don’t, like the Hyundai Ioniq EV. (It should be noted that some hybrids, such as Toyota and Lexus hybrids, utilize boost converters to goose acceleration.)
Linear Labs says the HET does the job of the DC/DC boost converter on its own by changing the relative position of one or more of its four rotors, analogous to the variable cam system on an ICE, altering position depending on load needs. Combining the extra torque, reduced weight and complexity possible without a gearbox or boost converter, and lighter ancillaries, Linear Labs claims the HET could increase range by 10%.
A carmaker says …
No automaker will address claims by a company it has never heard of about a component it has never used. Still, we wanted to get OEM commentary to compare to Linear Labs’ statements. We contacted Chevrolet, Tesla, and Hyundai. Only Hyundai agreed to a Q&A, connecting us with Jerome Gregeois, a senior manager at a Hyundai Group powertrain facility, and Ryan Miller, the manager for Hyundai’s electrified powertrain development team.
Gregeois said OEMs invest so much in batteries because they’re “so much more expensive than any of the [other] components,” and there’s so much more efficiency to be extracted from battery chemistry. Therefore, “The only way to reach competitive pricing compared to internal combustion engines or hybrids is really to get battery costs lower and lower.”
Concerning motors, Miller said, “Our focus and the industry’s focus on motors has been transitioning to silicon-carbide-based motor inverters.” The motor inverter converts the battery pack’s direct current (DC) into the alternating current (AC) used to power the electric motors that provide drive to the vehicle. Under regenerative braking, the motor inverter does the opposite – turning AC from the motors back into DC to recharge the battery. Silicon carbide technology, which the IEEE called “Smaller, faster, tougher,” is seen as enabling something like a 50% reduction in inverter volume.
View photos Illustration courtesy Hyundai
Miller told us the permanent magnet motor in the Hyundai Ioniq is about 50 kilograms, or 110 pounds. The gearbox, which contains a final drive and a differential, is about 70 pounds. “It’s not light,” he said, “because gears are generally steel.” As for volume, the gearbox occupies about 70% of the volume of the motor.
We asked Gregeois and Miller if a direct-drive motor that allowed elimination of the gearbox would make an enormous difference in cost or complexity of the powertrain. Said Gregeois, “We think cost-wise that gearbox is going to be cheaper than two motors.” Miller added, “Steel and aluminum is very cheap.”
One automaker example doesn’t negate the benefits of the Hunstable Electric Turbine, and Brad Hunstable believes the savings are there. “Every drivetrain can be designed and engineered multiple ways,” he said. “But if you have two motors that produce twice the torque in half the size as one conventional motor that must utilize a gearbox, then there is no comparison. HET wins. Of course, for the short-term mass-market vehicle, one motor driving directly into the differential is the most likely scenario, still eliminating the standard … gearbox.”
And automakers are throwing money at improving their motors. Honda improved the electric motor in the Accord Hybrid by using square copper wires for the stator windings, and three magnets instead of two on the rotor. The changes are said to have added 6 pound-feet of torque and 14 horsepower.
View photos Illustration by Linear Labs
The First Inning
We asked Brad how long he thought it would be before we’d see an HET in a car like the Chevrolet Bolt. “Three or four, some say five years out … There are longer lead cycles to get into production for big companies, [but] we are in joint development agreements, we are testing with [automakers].”
There have been so many charlatans in the EV space that many of the stories we’ve read about the HET end in commenters attacking it like hyenas disemboweling a wildebeest.
“There’s a lot of smoke and mirrors in the motor space,” Brad acknowledged. “The difference in this one: We’ve built them. At the end of the day you can’t argue with something that’s built right in front of you.”
“We’re literally in the first inning of this technology,” he continued, “so there’s more things that we’ll continue to do that that’ll make this even better. But the first motors that we’re producing in the market are literally a quantum leap on everything that’s out there.”
The question, then, is whether that quantum leap makes sense from a cost and packaging perspective for the spectrum of EV manufacturers, or does it make sense primarily for luxury EV makers who can justify the HET’s cost. Can this one more efficient-yet-expensive component be countered and justified by removing a not-especially expensive thing (the gearbox) and removing some of these pretty expensive and heavy things (batteries)? Hyundai’s representatives weren’t so sure, but if this really is just the first inning for HET, perhaps more development and actual access by major manufacturers will provide the answer as the game goes on.
HPT has collaborated with NREL on perovskite ink for solar cells, like this one developed by NREL researcher David Moore (Photo by Dennis Schroeder,NREL).
For the past six years, a major US oil and gas holding company has been collaborating with the National Renewable Energy Lab on new breakthrough perovskite solar cell research. What a twist!
The effort has been conducted through a relatively new division of the firm and it hasn’t attracted much attention, except that earlier this month they finally let something slip on the newswires and now the cat’s out of the bag.
Hunt’s new perovskite research is a whole ‘nother kettle of fish. It could have a profound, widespread impact on the energy marketplace and accelerate the transition from fossil fuels to renewables.
That’s because perovskite technology canpush down solar costsfar below today’s costs. Perovskite solar cells are also lighter and more flexible, which means they have a greater range of application.
For a bonus, perovskite solar cells can be “printed” with a relatively conventional high-volume manufacturing process.
Perovskite solar cells are only just beginning to edge out of the laboratory, now that researchers have finallyworked out the kinks. Once they hit the shelves, they will kick the global solar market into a whole new level of activity.
As for why Hunt, last weekForbestook a crack at the mystery and noted that the current head of the family business, Hunter L. Hunt, spent the past 10 years creating and then spinning off a newhigh voltage power line company.
That venture, along with the company’s investment armHunt Energy Enterprises, indicates that Hunt Oil is looking more holistically at new high tech opportunities in the energy market aside from just digging up stuff out of the ground.
More & Better Perovskite Solar Cells
The main challenge with perovskite as a solar cell material is durability, and researchers have been trying various formulas to improve durability without sacrificing too much solar conversion efficiency.
The work came to fruit late last year, when Hunt was able to demonstrate an ink-based manufacturing process for its new solar cell, to the satisfaction of theInternational Electrotechnical Commission. According to Hunt, the new solar cell exceeds IEC standards for temperature, humidity, white light and ultraviolet stress while achieving a fairly impressive solar conversion efficiency of 18%.
Legacy companies like Hunt are not going to shed their fossil fuel interests willy-nilly, but in a press statement Hunter Hunt indicated that his family business is prepping for change.
“We strategically chose to develop perovskite solar several years ago; we envisioned its strategic importance as an innovative new energy technology in addressing the world’s energy needs for the future, as well playing a part in combating climate change,” he said. “As part of the global energy transition that is occurring, our solar team is hoping to make a meaningful contribution.”
The UCF-developed device is an important step in the fields of AI and robotics.
University of Central Florida researchers are helping to close the gap separating human and machine minds.
In a study featured as the cover article appearing today in the journal Science Advances, a UCF research team showed that by combining two promising nanomaterials into a new superstructure, they could create a nanoscale device that mimics the neural pathways of brain cells used for human vision.
“This is a baby step toward developing neuromorphic computers, which are computer processors that can simultaneously process and memorize information,” said Jayan Thomas, an associate professor in UCF’s NanoScience Technology Center and Department of Materials Science and Engineering. “This can reduce the processing time as well as the energy required for processing. At some time in the future, this invention may help to make robots that can think like humans.”
Thomas led the research in collaboration with Tania Roy, an assistant professor in UCF’s NanoScience Technology Center, and others at UCF’s NanoScience Technology Center and the Department of Materials Science and Engineering.
Roy said a potential use for the technology is for drone-assisted rescues.
“Imagine a drone that can fly without guidance to remote mountain sites and locate stranded mountaineers,” Roy said. “Today it is difficult since these drones need connectivity to remote servers to identify what they scan with their camera eye. Our device makes this drone truly autonomous because it can see just like a human.”
“Earlier research created a camera which captured the image and sent it to a server to be recognized, but our group created a single device that mimics the eye and the brain function together,” she said. “Our device can observe the image and recognize it on the spot.”
The trick to the innovation was growing nanoscale, light-sensitive perovskite quantum dots on the two-dimensional, atomic thick nanomaterial graphene. This combination allows the photoactive particles to capture light, convert it to electric charges and then have the charges directly transferred to the graphene, all in one step. The entire process takes place on an extremely thin film, about one-ten thousandths of the thickness of a human hair.
Basudev Pradhan, who was a Bhaskara Advanced Solar Energy fellow in Thomas’ lab and is currently an assistant professor in the Department of Energy Engineering at the Central University of Jharkhand in India, and Sonali Das, a postdoctoral fellow in Roy’s lab, are shared first authors of the study.
“Because of the nature of the superstructure, it shows a light-assisted memory effect,” Pradhan said. “This is similar to humans’ vision-related brain cells. The optoelectronic synapses we developed are highly relevant for brain-inspired, neuromorphic computing. This kind of superstructure will definitely lead to new directions in development of ultrathin optoelectronic devices.”
Das said there are also potential defense applications.
“Such features can also be used for aiding the vision of soldiers on the battlefield,” she said. “Further, our device can sense, detect and reconstruct an image along with extremely low power consumption, which makes it capable for long-term deployment in field applications.”
Neuromorphic computing is a long-standing goal of scientists in which computers can simultaneously process and store information, like the human brain does, for example, to allow vision. Currently, computers store and process information in separate places, which ultimately limits their performance.
To test their device’s ability to see objects through neuromorphic computing, the researchers used it in facial recognition experiments, Thomas said.
“The facial recognition experiment was a preliminary test to check our optoelectronic neuromorphic computing,” Thomas said. “Since our device mimics vision-related brain cells, facial recognition is one of the most important tests for our neuromorphic building block.”
They found that their device was able to successfully recognize the portraits of four different people.
The researchers said they plan to continue their collaboration to refine the device, including using it to develop a circuit-level system.
Study co-authors were Jinxin Li, Farzana Chowdhury, Jayesh Cherusseri, Deepak Pandey, Durjoy Dev, Adithi Krishnaprasad, Elizabeth Barrios, Andrew Towers, Andre Gesquiere, and Laurene Tetard.
Thomas joined UCF in 2011 and is a part of the NanoScience Technology Center with a joint appointment in the College of Optics and Photonics and the Department of Materials Science and Engineering in the College of Engineering. Previously, Thomas was at the University of Arizona in its College of Optical Sciences. He has several degrees including a doctorate in chemistry/materials science from Cochin University of Science and Technology in India.
Roy joined UCF in 2016 and is a part of the NanoScience Technology Center with a joint appointment in the Department of Materials Science and Engineering, the Department of Electrical and Computer Engineering and the Department of Physics. Her recent National Science Foundation CAREER award focuses on the development of devices for artificial intelligence applications. Roy was a postdoctoral scholar at the University of California, Berkeley prior to joining UCF. She received her doctorate in electrical engineering from Vanderbilt University.
A new study at the University of Georgia has found a way to attack cancer cells that is potentially less harmful to the patient.
Sodium chloride nanoparticles—more commonly known as salt—are toxic to cancer cells and offer the potential for therapies that have fewer negative side effects than current treatments.
Led by Jin Xie, associate professor of chemistry, the study found that SCNPs can be used as a Trojan horse to deliver ions into cells and disrupt their internal environment, leading to cell death. SCNPs become salt when they degrade, so they’re not harmful to the body.
“This technology is well suited for localized destruction of cancer cells,” said Xie, a faculty member in the Franklin College of Arts and Sciences. “We expect it to find wide applications in treatment of bladder, prostate, liver, and head and neck cancer.”
Nanoparticles are the key to delivering SCNPs into cells, according to Xie and the team of researchers. Cell membranes maintain a gradient that keeps relatively low sodium concentrations inside cells and relatively high sodium concentrations outside cells.
The plasma membrane prevents sodium from entering a cell, but SCNPs are able to pass through because the cell doesn’t recognize them as sodium ions.
Once inside a cell, SCNPs dissolve into millions of sodium and chloride ions that are trapped inside by the gradient and overwhelm protective mechanisms, inducing rupture of the plasma membrane and cell death. When the plasma membrane ruptures, the molecules that leak out signal the immune system that there’s tissue damage, inducing an inflammatory response that helps the body fight pathogens.
“This mechanism is actually more toxic to cancer cells than normal cells, because cancer cells have relatively high sodium concentrations to start with,” Xie said.
Using a mouse model, Xie and the team tested SCNPs as a potential cancer therapeutic, injecting SCNPs into tumors. They found that SCNP treatment suppressed tumor growth by 66 percent compared to the control group, with no drop in body weight and no sign of toxicity to major organs.
They also performed a vaccination study, inoculating mice with cancer cells that had been killed via SCNPs or freeze thaw. These mice showed much greater resistance to a subsequent live cancer cell challenge, with all animals remaining tumor free for more than two weeks.
The researchers also explored anti-cancer immunity in a tumor model. After injecting primary tumors with SCNPs and leaving secondary tumors untreated, they found that the secondary tumors grew at a much lower speed than the control, showing a tumor inhibition rate of 53 percent.
Collectively, the results suggest that SCNPs killed cancer cells and converted the dying cancer cells to an in situ vaccine.
SCNPs are unique in the world of inorganic particles because they are made of a benign material, and their toxicity is based on the nanoparticle form, according to Xie.
“With a relatively short half-life in aqueous solutions, SCNPs are best suited for localized rather than systemic therapy. The treatment will cause immediate and immunogenic cancer cell death,” he said. “After the treatment, the nanoparticles are reduced to salts, which are merged with the body’s fluid system and cause no systematic or accumulative toxicity. No sign of systematic toxicity was observed with SCNPs injected at high doses.”
Melanoma in skin biopsy with H&E stain — this case may represent superficial spreading melanoma. Credit: Wikipedia/CC BY-SA 3.0
Researchers at Tel Aviv University have developed a novel nano-vaccine for melanoma, the most aggressive type of skin cancer. Their innovative approach has so far proven effective in preventing the development of melanoma in mouse models and in treating primary tumors and metastases that result from melanoma.
The focus of the research is on a nanoparticle that serves as the basis for the new vaccine. The study was led by Prof. Ronit Satchi-Fainaro, chair of the Department of Physiology and Pharmacology and head of the Laboratory for Cancer Research and Nanomedicine at TAU’s Sackler Faculty of Medicine, and Prof. Helena Florindo of the University of Lisbon while on sabbatical at the Satchi-Fainaro lab at TAU; it was conducted by Dr. Anna Scomparin of Prof. Satchi-Fainaro’s TAU lab, and postdoctoral fellow Dr. João Conniot. The results were published on August 5 inNature Nanotechnology.
Melanoma develops in the skin cells that produce melanin or skin pigment. “The war against cancer in general, and melanoma in particular, has advanced over the years through a variety of treatment modalities, such as chemotherapy, radiation therapy and immunotherapy; but the vaccine approach, which has proven so effective against various viral diseases, has not materialized yet against cancer,” says Prof. Satchi-Fainaro. “In our study, we have shown for the first time that it is possible to produce an effective nano-vaccine against melanoma and to sensitize theimmune systemto immunotherapies.”
The researchers harnessed tiny particles, about 170 nanometers in size, made of a biodegradable polymer. Within each particle, they “packed” two peptides—short chains of amino acids, which are expressed in melanoma cells. They then injected the nanoparticles (or “nano-vaccines”) into amouse modelbearing melanoma.
“The nanoparticles acted just like known vaccines for viral-borne diseases,” Prof. Satchi-Fainaro explains. “They stimulated the immune system of the mice, and the immune cells learned to identify and attack cells containing the two peptides—that is, the melanoma cells. This meant that, from now on, the immune system of the immunized mice will attack melanoma cells if and when they appear in the body.”
The researchers then examined the effectiveness of the vaccine under three different conditions.
First, the vaccine proved to have prophylactic effects. The vaccine was injected into healthy mice, and an injection of melanomacellsfollowed. “The result was that the mice did not get sick, meaning that the vaccine prevented the disease,” says Prof. Satchi-Fainaro.
Second, the nanoparticle was used to treat a primary tumor: A combination of the innovative vaccine and immunotherapy treatments was tested on melanoma model mice. The synergistic treatment significantly delayed the progression of the disease and greatly extended the lives of all treated mice.
Finally, the researchers validated their approach on tissues taken from patients with melanoma brain metastases. This suggested that the nano-vaccinecan be used to treat brain metastases as well. Mouse models with late-stage melanoma brain metastases had already been established following excision of the primary melanoma lesion, mimicking the clinical setting. Research on image-guided surgery of primary melanoma using smart probes was published last year by Prof. Satchi-Fainaro’s lab.
“Our research opens the door to a completely new approach—thevaccine approach—for effective treatment ofmelanoma, even in the most advanced stages of the disease,” concludes Prof. Satchi-Fainaro. “We believe that our platform may also be suitable for other types of cancer and that our work is a solid foundation for the development of other cancer nano-vaccines.”
Abstract:
Researchers at Oregon State University have developed an improved technique for using magnetic nanoclusters to kill hard-to-reach tumors.
Magnetic nanoparticles – tiny pieces of matter as small as one-billionth of a meter – have shown anti-cancer promise for tumors easily accessible by syringe, allowing the particles to be injected directly into the cancerous growth.
Once injected into the tumor, the nanoparticles are exposed to an alternating magnetic field, or AMF. This field causes the nanoparticles to reach temperatures in excess of 100 degrees Fahrenheit, which causes the cancer cells to die.
But for some cancer types such as prostate cancer, or the ovarian cancer used in the Oregon State study, direct injection is difficult. In those types of cases, a “systemic” delivery method – intravenous injection, or injection into the abdominal cavity – would be easier and more effective.
The challenge for researchers has been finding the right kind of nanoparticles – ones that, when administered systemically in clinically appropriate doses, accumulate in the tumor well enough to allow the AMF to heat cancer cells to death.
Olena Taratula and Oleh Taratula of the OSU College of Pharmacy tackled the problem by developing nanoclusters, multiatom collections of nanoparticles, with enhanced heating efficiency. The nanoclusters are hexagon-shaped iron oxide nanoparticles doped with cobalt and manganese and loaded into biodegradable nanocarriers.
Findings were published in ACS Nano.
“There had been many attempts to develop nanoparticles that could be administered systemically in safe doses and still allow for hot enough temperatures inside the tumor,” said Olena Taratula, associate professor of pharmaceutical sciences. “Our new nanoplatform is a milestone for treating difficult-to-access tumors with magnetic hyperthermia. This is a proof of concept, and the nanoclusters could potentially be optimized for even greater heating efficiency.”
The nanoclusters’ ability to reach therapeutically relevant temperatures in tumors following a single, low-dose IV injection opens the door to exploiting the full potential of magnetic hyperthermia in treating cancer, either by itself or with other therapies, she added.
“It’s already been shown that magnetic hyperthermia at moderate temperatures increases the susceptibility of cancer cells to chemotherapy, radiation and immunotherapy,” Taratula said.
The mouse model in this research involved animals receiving IV nanocluster injections after ovarian tumors had been grafted underneath their skin.
“To advance this technology, future studies need to use orthotopic animal models – models where deep-seated tumors are studied in the location they would actually occur in the body,” she said. “In addition, to minimize the heating of healthy tissue, current AMF systems need to be optimized, or new ones developed.”
The National Institutes of Health, the OSU College of Pharmacy and Najran University of Saudi Arabia supported this research.
Also collaborating were OSU electrical engineering professor Pallavi Dhagat, postdoctoral scholars Xiaoning Li and Canan Schumann of the College of Pharmacy, pharmacy graduate students Hassan Albarqi, Fahad Sabei and Abraham Moses, engineering graduate student Mikkel Hansen, and pre-pharmacy undergrads Tetiana Korzun and Leon Wong.
RESEARCH TRIANGLE PARK, N.C. — Army research is the first to develop computational models using a microbiology procedure that may be used to improve novel cancer treatments and treat combat wounds.
Using the technique, known as electroporation, an electrical field is applied to cells in order to increase the permeability of the cell membrane, allowing chemicals, drugs, or DNA to be introduced into the cell.
For example, electro-chemotherapy is a cutting-edge cancer treatment that uses electroporation as a means to deliver chemotherapy into cancerous cells.
The research, funded by the U.S. Army and conducted by researchers at University of California, Santa Barbara and Université de Bordeaux, France, has developed a computational approach for parallel simulations that models the complex bioelectrical interaction at the tissue scale.
Previously, most research has been conducted on individual cells, and each cell behaves according to certain rules.
“When you consider a large number of them together, the aggregate exhibits novel coherent behaviors,” said Pouria Mistani, a researcher at UCSB. “It is this emergent phenomenon that is crucial for developing effective theories at the tissue-scale — novel behaviors that emerge from the coupling of many individual elements.”
This new research, published in the Journal of Computational Physics, is funded by the U.S. Combat Capabilities Development Command’s Army Research Lab, the Army’s corporate research laboratory known as ARL, through its Army Research Office.
“Mathematical research enables us to study the bioelectric effects of cells in order to develop new anti-cancer strategies,” said Dr. Joseph Myers, Army Research Office mathematical sciences division chief.
“This new research will enable more accurate and capable virtual experiments of the evolution and treatment of cells, cancerous or healthy, in response to a variety of candidate drugs.”
Researchers said a crucial element in making this possible is the development of advanced computational algorithms.
“There is quite a lot of mathematics that goes into the design of algorithms that can consider tens of thousands well-resolved cells,” said Frederic Gibou, a faculty member in the Department of Mechanical Engineering and Computer Science at UCSB.
Another potential application is accelerating combat wound healing using electric pulsation.
“It’s an exciting, but mainly unexplored area that stems from a deeper discussion at the frontier of developmental biology, namely how electricity influences morphogenesis,” — or the biological process that causes an organism to develop its shape — Gibou said. “In wound healing, the goal is to externally manipulate electric cues to guide cells to grow faster in the wounded region and accelerate the healing process.”
The common factor among these applications is their bioelectric physical nature. In recent years, it has been established that the bioelectric nature of living organisms plays a pivotal role in the development of their form and growth.
To understand bioelectric phenomena, Gibou’s group considered computer experiments on multicellular spheroids in 3-D. Spheroids are aggregates of a few tens of thousands of cells that are used in biology because of their structural and functional similarity with tumors.
“We started from the phenomenological cell-scale model that was developed in the research group of our colleague, Clair Poignard, at the Université de Bordeaux, France, with whom we have collaborated for several years,” Gibou said.
This model, which describes the evolution of transmembrane potential on an isolated cell, has been compared and validated with the response of a single cell in experiments.
“From there, we developed the first computational framework that is able to consider a cell aggregate of tens of thousands of cells and to simulate their interactions,” he said. “The end goal is to develop an effective tissue-scale theory for electroporation.”
One of the main reasons for the absence of an effective theory at the tissue scale is the lack of data, according to Gibou and Mistani. Specifically, the missing data in the case of electroporation is the time evolution of the transmembrane potential of each individual cell in a tissue environment. Experiments are not able to make those measurements, they said.
“Currently, experimental limitations prevent the development of an effective tissue-level electroporation theory,” Mistani said. “Our work has developed a computational approach that can simulate the response of individual cells in a spheroid to an electric field as well as their mutual interactions.”
Each cell behaves according to certain rules.
“But when you consider a large number of them together, the aggregate exhibits novel coherent behaviors,” Mistani said. “It is this emergent phenomenon that is crucial for developing effective theories at the tissue-scale — novel behaviors that emerge from the coupling of many individual elements.”
The effects of electroporation used in cancer treatment, for example, depend on many factors, such as the strength of the electric field, its pulse and frequency.
“This work could bring an effective theory that helps understand the tissue response to these parameters and thus optimize such treatments,” Mistani said. “Before our work, the largest existing simulations of cell aggregate electroporation only considered about one hundred cells in 3-D, or were limited to 2-D simulations. Those simulations either ignored the real 3-D nature of spheroids or considered too few cells for tissue-scale emergent behaviors to manifest.”
The researchers are currently mining this unique dataset to develop an effective tissue-scale theory of cell aggregate electroporation.
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The CCDC Army Research Laboratory (ARL) is an element of the U.S. Army Combat Capabilities Development Command. As the Army’s corporate research laboratory, ARL discovers, innovates and transitions science and technology to ensure dominant strategic land power. Through collaboration across the command’s core technical competencies, CCDC leads in the discovery, development and delivery of the technology-based capabilities required to make Soldiers more effective to win our Nation’s wars and come home safely. CCDC is a major subordinate command of the U.S. Army Futures Command.
Researchers test two identical outdoor experimental setups placed next to each other. Credit: MIT
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