TL;DR

• Researchers from Oxford University’s Department of Materials have developed a technique to precisely manipulate and place nanowires with sub-micron accuracy. This discovery could accelerate the development of even smaller and more powerful computer chips.
• In a recent study, researchers from Xi’an Jiaotong-Liverpool University and other universities in China have reported that brain stimulation combined with a nose spray containing nanoparticles can improve recovery after ischemic stroke in an animal model.
• A research team led by Professor Lee Sungwon from DGIST succeeded in developing the world’s first nanomesh-structured electronic skin device (organic field-effect transistor). This electronic skin device, comprising only a nanomesh structure that can measure and process bio-signals for a prolonged period, is a big step toward integrated systems for electronic skin devices.
• Researchers report the development of ultrahigh refractive index metamaterials which are integrated with a low refractive index polymer producing distributed Bragg reflector (DBR). The highest refractive index in the visible and near-infrared regions was reported. The new technology is applicable to precision semiconductor processes and high-resolution display technology.
• University of Central Florida material sciences engineers Melanie Coathup and Sudipta Seal have designed a cerium oxide nanoparticle — an artificial enzyme — that protects bones against damage from radiation. The nanoparticle has also shown abilities to improve bone regeneration, reduce loss of blood cells and help kill cancer cells.
• Researchers at the MIT Media Lab have designed a miniature antenna that can operate wirelessly inside of a living cell, opening up possibilities in medical diagnostics and treatment and other scientific processes because of the antenna’s potential for monitoring and even directing cellular activity in real time.
• Nanoengineers at the University of California San Diego have developed microscopic robots, called microrobots, that can swim around in the lungs, deliver medication, and be used to clear up life-threatening cases of bacterial pneumonia.
• New nanophotonic material has broken records for high-temperature stability, potentially ushering in more efficient electricity production and opening a variety of new possibilities in the control and conversion of thermal radiation.
• New technology and approach have allowed researchers to peer within the atomic layers of nanomaterials to better understand the connection between their form and function.
• Researchers develop a technology that produces more than 100 microrobots per minute that can be disintegrated into the body.
• And more!

Nanotech Market

Nanotechnology deals with the ability to see, understand, measure, predict, produce or control matter at the nanoscale (below 100 nanometers). The realm of nanotechnology lies between 0.1 and 100 nanometers, wherein a nanometer is defined as one-thousandth of a micron. As a versatile technology with widespread applications in a wide range of end-use sectors, nanotechnology is currently facing a mixed bag of challenges and opportunities as the COVID-19 pandemic continues to spread across the globe. With the world fighting its biggest public health crisis in history, nanotechnology healthcare applications are storming into the spotlight led by the focus on nano intervention in terms of designing effective ways to identify, diagnose, treat and eliminate the spread of COVID-19 infections. Their role as nanocarriers has the potential to design risk-free and effective immunization strategies. In the post-COVID-19 period, the use of nanotechnology solutions in the production of a multitude of devices & products will continue to grow.

Amid the COVID-19 crisis, the global market for Nanotechnology estimated at US$42.2 Billion in the year 2020, is projected to reach a revised size of US$70.7 Billion by 2026, growing at a CAGR of 9.2% over the analysis period. Nanocomposites, one of the segments analyzed in the report, is projected to record a 8.7% CAGR and reach US$35.4 Billion by the end of the analysis period. After a thorough analysis of the business implications of the pandemic and its induced economic crisis, growth in the Nanomaterials segment is readjusted to a revised 10.1% CAGR for the next 7-year period.

Global nanotechnology market to reach US $126.8 billion by the year 2027. Amid the COVID-19 crisis, the global market for Nanotechnology is estimated at the US $54.2 billion in the year 2020, and is projected to reach a revised size of US $126 billion.

Latest News & Research

A Universal Pick‐and‐Place Assembly for Nanowires

by Utku Emre Ali et al in Small

Researchers from Oxford University’s Department of Materials have developed a technique to precisely manipulate and place nanowires with sub-micron accuracy. This discovery could accelerate the development of even smaller and more powerful computer chips.

In a newly published study, a team of researchers in Oxford University’s Department of Materials led by Harish Bhaskaran, Professor of Applied Nanomaterials, describe a breakthrough approach to pick up single nanowires from the growth substrate and place them on virtually any platform with sub-micron accuracy.

The innovative method uses novel tools, including ultra-thin filaments of polyethylene terephthalate (PET) with tapered nanoscale tips that are used to pick up individual nanowires. At this fine scale, adhesive van der Walls forces (tiny forces of attraction that occur between atoms and molecules) cause the nanowires to “jump” into contact with the tips. The nanowires are then transferred to a transparent dome-shaped elastic stamp mounted on a glass slide. This stamp is then turned upside down and aligned with the device chip, with the nanowire then printed gently onto the surface.

Deposited nanowires showed strong adhesive qualities, remaining in place even when the device was immersed in liquid. The research team was also able to place nanowires on fragile substrates, such as ultra-thin 50 nanometer membranes, demonstrating the delicacy and versatility of the stamping technique.

In addition, the researchers used the method to build an optomechanical sensor (an instrument that uses laser light to measure vibrations) that was 20 times more sensitive than existing nanowire-based devices.

Nanowires, materials with diameters 1,000 times smaller than a human hair and fascinating physical properties, could enable major advancements in many different fields, from energy harvesters and sensors, to information and quantum technologies. In particular, their minuscule size could allow the development of smaller transistors and miniaturized computer chips. A major obstacle, however, to realizing the full potential of nanowires has been the inability to precisely position them within devices.

Most electronic device manufacturing techniques cannot tolerate the conditions needed to produce nanowires. Consequently, nanowires are usually grown on a separate substrate and then mechanically or chemically transferred to the device. In all existing nanowire transfer techniques, however, the nanowires are placed randomly onto the chip surface, which limits their application in commercial devices.

DPhil student Utku Emre Ali (Department of Materials), who developed the technique, said, “This new pick-and-place assembly process has enabled us to create first-of-its-kind devices in the nanowire realm. We believe that it will inexpensively advance nanowire research by allowing users to incorporate nanowires with existing on-chip platforms, be it electronic or photonic, unlocking physical properties that have not been attainable so far. Furthermore, this technique could be fully automated, making full-scale fabrication of high quality nanowire-integrated chips a real possibility.”

Nanowire transfer process. a) A single nanowire is picked up by the tapered polymer tip from a forest of nanowires on the growth substrate. The nanowire adheres to the tip due to the enhanced van der Waals forces overcoming the weaker interactions between smooth, crystalline nanowire surfaces. b) The nanowire on the tip is placed onto a dome-shaped PDMS stamp cured over a glass slide. Note that the adhesion of the PDMS stamp to the nanowire is greater than that of the tip. c) The stamp with the nanowire is turned upside down and its alignment with the device chip is done under a light microscope. Following alignment, the stamp is imprinted over electrodes on the device substrate. d) Nanowire deposition is completed with the removal of the stamp. Credit: Small (2022). DOI: 10.1002/smll.202201968

Enhancing non-invasive brain stimulation with non-invasively delivered nanoparticles for improving stroke recovery

by Y. Hong et al in Materials Today Chemistry

In a recent study, researchers from Xi’an Jiaotong-Liverpool University and other universities in China have reported that brain stimulation combined with a nose spray containing nanoparticles can improve recovery after ischemic stroke in an animal model.

The nasal spray is a non-invasive method for delivering magnetic nanoparticles into the brain that the study finds can increase the benefits of transcranial magnetic stimulation (TMS). TMS is a method of non-invasive brain stimulation already used clinically or in clinical trials to treat neurological conditions like stroke, Parkinson’s disease, Alzheimer’s disease, depression, and addiction.

Rats that were given combined nanoparticle and TMS treatment every 24 hours for 14 days after an ischemic stroke had better overall health, put on weight more quickly and had improved cognitive and motor functions compared to those treated with TMS alone.

During TMS treatment, an electrical current runs through an electric coil placed outside the skull, producing a magnetic field that stimulates brain cells by inducing a further electrical current inside the brain. However, the stimulation is often not intense enough to penetrate far enough into the brain to reach the areas needing treatment.

In this new study, published in Materials Today Chemistry, the researchers show that magnetic nanoparticles, administered intranasally, can make neurons more responsive and amplify the magnetic signal from TMS to reach deeper brain tissue, aiding recovery. The finding offers new opportunities for treating neurological disorders.

The research answers a key question in nanomedicine — whether it is possible to enhance TMS by using nanoparticles that are non-invasively delivered into the brain. Leading figures in the field previously stated that it was almost impossible because of the blood-brain barrier. This physical barrier separates the brain from the rest of the body’s bloodstream.

However, the team of researchers overcame this by guiding the magnetic nanoparticles closer to the correct area with a large magnet near the head.

Dr. Gang Ruan, a corresponding author of the study, says, “We were able to overcome the blood-brain barrier and send enough nanoparticles into the brain to use in combination with TMS simulation to improve recovery from stroke.

“TMS devices are already used for the clinical treatment of neurological disorders but have severe limitations in terms of stimulation strength and depths of the brain they can penetrate.

“By non-invasively putting magnetic nanoparticles into the brain, we can amplify and enhance the TMS stimulation effects on neurons, making the treatment more effective,” Dr. Ruan adds. “Showing it is possible to use nanoparticles in this way paves the way for medical applications of nanoparticles for other neurological disorders.”

MRI view of rat brains after delivery of nanoparticles: The dark spots pointed to by red arrows and circled by red boxes indicate nanoparticles. The yellow arrow shows the location of the permanent magnet placed on the skull to attract the nanoparticles. (I.v., intravenous administration. i.n., intranasal administration. Sample size for imaging is 5 male rats.). Credit: Dr Gang Ruan, Xi’an Jiaotong-Liverpool University

An All‐Nanofiber‐Based Substrate‐Less, Extremely Conformal, and Breathable Organic Field Effect Transistor for Biomedical Applications

by Gihyeok Gwon et al in Advanced Functional Materials

A research team led by Professor Lee Sungwon from DGIST succeeded in developing the world’s first nanomesh-structured electronic skin device (organic field-effect transistor). This electronic skin device, comprising only a nanomesh structure that can measure and process bio-signals for a prolonged period, is a big step toward integrated systems for electronic skin devices.

The research team, led by professor Lee Sungwon from the Department of physics and chemistry at DGIST, succeeded in developing the world’s first ultrathin and breathable nanomesh organic field-effect transistor (OFET) that can be applied to electronic skin devices. Nanomesh OFET, in combination with various sensors, is expected to enable direct measurement of physiological data from the skin surface and optimize data processing.

Electronic skin refers to electronic wearable devices worn on the skin to collect biosignals, such as temperature, heart rate, electromyogram, and blood pressure, and transfer the data. In response to the recent increase in interest in smart health care systems with wearable devices, related technologies are being actively developed. A soft sensor that can attach to smooth and constantly moving skin surfaces is required to accurately measure physiological signals using a real-time health care system. As a result, most electronic devices worn on the skin surface have been manufactured using substrates with flat surfaces such as plastic and rubber.

However, long-term attachment of substrate with a flat surface structure and low liquid and vapor permeability to biological skin can cause unexpected diseases to occur (such as atopy, metabolic disorders, among others). Hence, it is necessary for electronic devices that come in contact with biological tissues to achieve high permeability to ensure long-term use. Accordingly, research on polymer nanofiber-based nanomesh devices with good permeability has been attracting considerable attention.

The research team led by Lee Sungwon at DGIST developed an ultra-thin nanomesh OFET that causes almost no discomfort for the users and can be combined with various sensors. In particular, the developed OFET device showed consistent functions even when folded or curved, with almost no performance degradations, even in severe environments such as 1,000 deformations and high humidity.

Manufacturing nanomesh transistors was difficult due to the rough surface and lack of mechanical robustness and thermal and chemical stability. Professor Lee Sungwon’s team solved these problems simultaneously by using a material called Parylene C as a biocompatible coating. In addition, the conventional vacuum deposition method was used for simpler processing instead of synthesizing or high-temperature processing.

Professor Lee Sungwon from the Department of physics and chemistry at DGIST said, “We have successfully developed a nanomesh organic field-effect transistor for the first time and demonstrated an integrated active-matrix tactile sensor. The development of transistors was essential for building a complex circuit, and now with the nanomesh electronic skin device, long-term measurement and processing of physiological data in real time is possible.”

A Biodegradable Magnetic Microrobot Based on Gelatin Methacrylate for Precise Delivery of Stem Cells with Mass Production Capability

by Seungmin Noh et al in Small

Daegu Gyeongbuk Institute of Science & Technology (DGIST, President Yang Kook) Professor Hongsoo Choi’s team of the Department of Robotics and Mechatronics Engineering collaborated with Professor Sung-Won Kim’s team at Seoul St. Mary’s Hospital, Catholic University of Korea, and Professor Bradley J. Nelson’s team at ETH Zurich to develop a technology that produces more than 100 microrobots per minute that can be disintegrated in the body.

Microrobots aiming at minimal invasive targeted precision therapy can be manufactured in various ways. Among them, ultra-fine 3D printing technology called two-photon polymerization method, a method that triggers polymerization by intersecting two lasers in synthetic resin, is the most used. This technology can produce a structure with nanometer-level precision. However, a disadvantage exists in that producing one microrobot is time-consuming because voxels, the pixels realized by 3D printing, must be cured successively. In addition, the magnetic nanoparticles contained in the robot can block the light path during the two-photon polymerization process. This process result may not be uniform when using magnetic nanoparticles with high concentration.

To overcome the limitations of the existing microrobot manufacturing method, DGIST Professor Hongsoo Choi’s research team developed a method to create microrobots at a high speed of 100 per minute by flowing a mixture of magnetic nanoparticles and gelatin methacrylate, which is biodegradable and can be cured by light, into the microfluidic chip. This is more than 10,000 times faster than using the existing two-photon polymerization method to manufacture microrobots.

Then, the microrobot produced with this technology was cultured with human nasal turbinated stem cells collected from the human nose to induce stem cell adherence to the surface of the microrobot. Through this process, a stem cell carrying a microrobot, including magnetic nanoparticles inside and stem cells attached to the exterior surface, was fabricated. The robot moves as the magnetic nanoparticles inside the robot respond to an external magnetic field and can be moved to the desired position.

Selective cell delivery was difficult in the case of the existing stem cell therapy. However, the stem cell carrying microrobot can move to the desired location by controlling the magnetic field generated from the electromagnetic field control system in real time. The research team conducted an experiment to examine whether the stem cell carrying microrobot could reach the target point by passing through a maze-shaped microchannel, and consequently confirmed that the robot could move to the desired location.

In addition, the degradability of the microrobot was evaluated by incubating the stem cell carrying microrobot with degrading enzyme. After 6 hours of incubation, the microrobot was completely disintegrated, and the magnetic nanoparticles inside the robot were collected by the magnetic field generated from the magnetic field control system. Stem cells proliferated at the location where the microrobot was disintegrated. Subsequently, the stem cells were induced to differentiate into nerve cells to confirm normal differentiation; the stem cells were differentiated into nerve cells after approximately 21 days. This experiment verified that delivering stem cells to the desired location using a microrobot was possible and that the delivered stem cells could serve as a targeted precision therapeutic agent by exhibiting proliferation and differentiation.

Furthermore, the research team confirmed whether the stem cells delivered by the microrobot exhibited normal electrical and physiological characteristics. The final goal of this study is to ensure that the stem cells delivered by the robot normally perform their bridge role in a state where the connection between the existing nerve cells is disconnected. To confirm this, hippocampal neurons extracted from rat embryo that stably emit electrical signals were utilized. The corresponding cell was attached to the surface of the microrobot, cultured on a micro-sized electrode chip, and electrical signals were observed from the hippocampal neurons after 28 days. Through this, the microrobot was verified to properly perform its role as a cell delivery platform.

DGIST Professor Hongsoo Choi said, “We expect that the technologies developed through this study, such as mass production of microrobots, precise operation by electromagnetic fields, and stem cell delivery and differentiation, will dramatically increase the efficiency of targeted precision therapy in the future.”

Oxycarbide MXenes and MAX phases identification using monoatomic layer-by-layer analysis with ultralow-energy secondary-ion mass spectrometry

by Paweł P. Michałowski, Mark Anayee, Tyler S. Mathis, Sylwia Kozdra, Adrianna Wójcik, Kanit Hantanasirisakul, Iwona Jóźwik, Anna Piątkowska, Małgorzata Możdżonek, Agnieszka Malinowska, Ryszard Diduszko, Edyta Wierzbicka, Yury Gogotsi in Nature Nanotechnology

Since the initial discovery of what has become a rapidly growing family of two-dimensional layered materials — called MXenes — in 2011, Drexel University researchers have made steady progress in understanding the complex chemical composition and structure, as well as the physical and electrochemical properties, of these exceptionally versatile materials. More than a decade later, advanced instruments and a new approach have allowed the team to peer within the atomic layers to better understand the connection between the materials’ form and function.

In a paper recently published in Nature Nanotechnology, researchers from Drexel’s College of Engineering and Poland’s Warsaw Institute of Technology and Institute of Microelectronics and Photonics reported a new way to look at the atoms that make up MXenes and their precursor materials, MAX phases, using a technique called secondary ion mass spectrometry. In doing so, the group discovered atoms in locations where they were not expected and imperfections in the two-dimensional materials that could explain some of their unique physical properties. They also demonstrated the existence of an entirely new subfamily of MXenes, called oxycarbides, which are two-dimensional materials where up to 30% of carbon atoms are replaced by oxygen.

This discovery will enable researchers to build new MXenes and other nanomaterials with tunable properties best suited for specific applications from antennas for 5G and 6G wireless communication and shields for electromagnetic interference; to filters for hydrogen production, storage and separation; to wearable kidneys for dialysis patients.

“Better understanding of the detailed structure and composition of two-dimensional materials will allow us to unlock their full potential,” said Yury Gogotsi, PhD, Distinguished University and Bach professor in the College, who led the MXene characterization research. “We now have a clearer picture of why MXenes behave the way they do and will be able to tailor their structure and therefore behaviors for important new applications.”

Secondary-ion mass spectrometry (SIMS) is a commonly used technique to study solid surfaces and thin films and how their chemistry changes with depth. It works by shooting a beam of charged particles at a sample, which bombards the atoms on the surface of the material and ejects them — a process called sputtering. The ejected ions are detected, collected and identified based on their mass and serve as indicators of the composition of the material.

While SIMS has been used to study multi-layered materials over the years, the depth resolution has been limited examining the surface of a material (several angstroms). A team led by Pawel Michalowski, PhD, from Poland’s Institute of Microelectronics and Photonics, made a number of improvements to the technique, including adjusting the angle and energy of the beam, how the ejected ions are measured; and cleaning the surface of the samples, which allowed them to sputter samples layer by layer. This allowed the researchers to view the sample with an atom-level resolution that had not been previously possible.

“The closest technique for analysis of thin layers and surfaces of MXenes is X-ray photoelectron spectroscopy, which we have been using at Drexel starting from the discovery of the first MXene,” said Mark Anayee, a doctoral candidate in Gogotsi’s group. “While XPS only gave us a look at the surface of the materials, SIMS lets us analyze the layers beneath the surface. It allows us to ‘remove’ precisely one layer of atoms at a time without disturbing the ones beneath it. This can give us a much clearer picture that would not be possible with any other laboratory technique.”

As the team peeled back the upper layer of atoms, like an archaeologist carefully unearthing a new find, the researchers began to see the subtle features of the chemical scaffolding within the layers of materials, revealing the unexpected presence and positioning of atoms, and various defects and imperfections.

“We demonstrated the formation of oxygen-containing MXenes, so-called oxycarbides. This represents a new subfamily of MXenes — which is a big discovery!” said Gogotsi. “Our results suggest that for every carbide MXene, there is an oxycarbide MXene, where oxygen replaces some carbon atoms in the lattice structure.”

Since MAX and MXenes represent a large family of materials, the researchers further explored more complex systems that include multiple metal elements. They made several pathbreaking observations, including the intermixing of atoms in chromium-titanium carbide MXene — which were previously thought to be separated into distinct layers. And they confirmed previous findings, such as the complete separation of molybdenum atoms to outer layers and titanium atoms to the inner layer in molybdenum-titanium carbide.

All of these findings are important for developing MXenes with a finely tuned structure and improved properties, according to Gogotsi.

“We can now control not only the total elemental composition of MXenes, but also know in which atomic layers the specific elements like carbon, oxygen, or metals are located,” said Gogotsi. “We know that eliminating oxygen helps to increase the environmental stability of titanium carbide MXene and increase its electronic conductivity. Now that we have a better understanding of how much additional oxygen is in the materials, we can adjust the recipe — so to speak — to produce MXenes that do not have it, and as a result more stable in the environment.”

The team also plans to explore ways to separate layers of chromium and titanium, which will help it develop MXenes with attractive magnetic properties. And now that the SIMS technique has proven to be effective, Gogotsi plans to use it in future research, including his recent $3 million U.S. Department of Energy-funded effort to explore MXenes for hydrogen storage — an important step toward the development of a new sustainable energy source.

“In many ways, studying MXenes for the last decade has been mapping uncharted territory,” said Gogotsi. “With this new approach, we have better guidance on where to look for new materials and applications.”

Percolated Plasmonic Superlattices of Nanospheres with 1 nm‐Level Gap as High‐Index Metamaterials

by Dong‐In Shin, Seong Soo Yoo, Seong Hun Park, Gaehang Lee, Wan Ki Bae, Seok Joon Kwon, Pil Jin Yoo, Gi‐Ra Yi in Advanced Materials

We all look in the mirror at least once a day to see our reflection. Mirrors are used not only in daily life but also in cutting-edge technologies such as semiconductor processing and high-resolution displays. Recently, a powerful Bragg reflection mirror based on high-index metamaterials has been developed that only reflects desired light.

A research team led by Professor Gi-Ra Yi (Department of Chemical Engineering) at POSTECH with the research team led by professors Seok Joon Kwon and Pil Jin Yoo (School of Chemical Engineering) at Sungkyunkwan University have together developed an ultrahigh refractive index metamaterial by closely packing gold nanospheres and a reflector that combines the metamaterial with a polymer.

Metamaterials — with properties that do not exist in nature — can be designed to have a negative (−) or ultrahigh refractive index. However, metamaterials with a high refractive index still have limitations from designing to manufacturing.

To overcome this issue, the research team developed a metamaterial that is uniformly arranged with the 1-nanometer-level gaps (nm, 1 billionth of a meter) by assembling spherical gold nanoparticles. This material, which maximizes light-matter interaction, recorded the highest refractive index in the visible and near-infrared regions. The 2D superstructures exhibited the highest-ever refractive index of 7.8

The distributed Bragg reflector (DBR), which is made by stacking these metamaterials and polymer layers with a low refractive index, strongly reflected specific wavelengths.

Furthermore, the research team established the theory of a plasmonic percolation model that can explain the extremely high refractive index. As it theoretically explains the ultrahigh refractive index of metamaterials that could not be explained in previous studies, the development of related research fields is anticipated in the future.

This study is also garnering attention from academic circles and industry for its applicability in precise semiconductor processes and high-resolution displays.

A novel approach for the prevention of ionizing radiation-induced bone loss using a designer multifunctional cerium oxide nanozyme

by Fei Wei et al in Bioactive Materials

University of Central Florida material sciences engineers Melanie Coathup and Sudipta Seal have designed a cerium oxide nanoparticle — an artificial enzyme — that protects bones against damage from radiation. The nanoparticle has also shown abilities to improve bone regeneration, reduce loss of blood cells and help kill cancer cells.

Their study, a collaboration with Oakland University, North Carolina A&T University, the University of Sheffield and the University of Huddersfield in the U.K., was published in Bioactive Materials.

Approximately 50% of all cancer patients receive radiation therapy — a treatment that uses electrically charged particles to kill cancer cells. About 40% of patients are cured with this therapy. However, bone damage is a side effect, impacting about 75% of patients receiving radiation.

“Because of its high calcium content, bone absorbs 30–40% more radiation than other tissues and so it is a common site of injury,” says Coathup, director UCF’s Biionix faculty cluster. “Radiation makes the bone brittle and easily fractured. And due to the damage caused by radiation, many people are then unable to repair their bone fracture. In some people, this leads to having an amputation to resolve the complication.”

While radiotherapy beams are directly aimed at the tumor, surrounding healthy tissue also gets damaged and can cause many additional health issues for patients.

“At the moment, there is no real drug or therapy to protect healthy tissue from the damage caused by radiation,” Coathup says. “This is not only a problem for cancer patients who undergo radiotherapy but also poses problems for astronauts and future deep space exploration.”

The body’s natural defense against radiation is a group of enzymes called antioxidants — but this defense system gets easily overwhelmed by radiation and on its own cannot protect the body from damage. Seal, a leading nanotechnologist, designed the cerium oxide nanoparticle — or nanoceria — that mimics the activity of these antioxidants and has a stronger defense mechanism in protecting cells against DNA damage.

“The nanoceria works with a specifically designed regenerative lattice structure responsible for destroying harmful reactive oxygen species, a byproduct of radiation treatment,” Seal says.

Working with postdoctoral researcher Fei Wei, Coathup tested the nanozyme in live models receiving radiation therapy.

“Our study showed that exposing rats to radiation at similar levels to those given to cancer patients led to weak and damaged bones,” Coathup says. “However, when we treated the animals with the nanozyme, before and during three doses of radiation over three days, we found that the bone was not damaged, and had a strength similar to healthy bone.”

The study also showed that the nanozyme treatment helped kill cancer cells, possibly due to an increase in acidity, and protected against the loss of white and red blood cells that usually occurs in cancer patients. A low white and red blood cell count means the patient is more susceptible to opportunistic infection, less able to fight cancer and is more fatigued. Another interesting finding is that the nanoparticle also enhanced healthy cells’ ability to produce more antioxidants, reduced inflammation (which also leads to bone loss) and promoted bone formation.

Future research will seek to determine the appropriate dosage and administration of the nanozyme and further explore how nanozyme helps to kill cancer cells. The researchers will also focus their studies in the context of breast cancer, as women are more susceptible to bone damage than men.

“Cancer patients are already struggling with fighting one disease,” Coathup says. “They shouldn’t have to be worried about bone fractures and tissue damage. So we’re hoping this breakthrough will help survivors go back to living a normal and healthy life.”

Cell Rover — a miniaturized magnetostrictive antenna for wireless operation inside living cells

by Baju Joy et al in Nature Communications

Researchers at the MIT Media Lab have designed a miniature antenna that can operate wirelessly inside of a living cell, opening up possibilities in medical diagnostics and treatment and other scientific processes because of the antenna’s potential for monitoring and even directing cellular activity in real time.

Schematic representation and operating principle of the Cell Rover. a Schematic diagram showing the wireless operation of a Cell Rover from inside a cell (Xenopus oocyte). The zoomed in view shows the Cell Rover and its equivalent circuit representation as a parallel RLC resonator. b Schematic diagram illustrating the principle of magnetostriction. The red and blue faces indicate north and south poles of the magnetic domains in the material respectively. The randomly oriented magnetic domains align in the direction of an applied magnetic field which in turn causes a strain in the material.

“The most exciting aspect of this research is we are able to create cyborgs at a cellular scale,” says Deblina Sarkar, assistant professor and AT&T Career Development Chair at the MIT Media Lab and head of the Nano-Cybernetic Biotrek Lab. “We are able to fuse the versatility of information technology at the level of cells, the building blocks of biology.”

The technology, named Cell Rover by the researchers, represents the first demonstration of an antenna that can operate inside a cell and is compatible with 3D biological systems. Typical bioelectronic interfaces, Sarkar says, are millimeters or even centimeters in size, and are not only highly invasive but also fail to provide the resolution needed to interact with single cells wirelessly — especially considering that changes to even one cell can affect a whole organism.

The antenna developed by Sarkar’s team is much smaller than a cell. In fact, in the team’s research with oocyte cells, the antenna represented less than .05 percent of the cell volume, putting it well below a size that would intrude upon and damage the cell.

Finding a way to build an antenna of that size to work inside a cell was a key challenge.

This is because conventional antennas need to be comparable in size to the wavelength of the electromagnetic waves they transmit and receive. Such wavelengths are very large — they represent the velocity of light divided by the wave frequency. At the same time, increasing the frequency in order to reduce that ratio and the size of the antenna is counterproductive because high frequencies produce heat damaging to living tissue.

The antenna developed by the Media Lab researchers converts electromagnetic waves into acoustic waves, whose wavelengths are five orders of magnitude smaller — representing the velocity of sound divided by the wave frequency — than those of the electromagnetic waves.

This conversion from electromagnetic to acoustic waves is accomplished by fabricating the miniature antennas using material that is referred to as magnetostrictive. When a magnetic field is applied to the antenna, powering and activating it, magnetic domains within the magnetostrictive material align to the field, creating strain in the material, the way metal bits woven into a piece of cloth could react to a strong magnet, causing the cloth to contort.

When an alternating magnetic field is applied to the antenna, the varying strain and stress (pressure) produced in the material is what creates the acoustic waves in the antenna, says Baju Joy, a student in Sarkar’s lab and the lead author of this work. “We have also developed a novel strategy using a non-uniform magnetic field to introduce the rovers into the cells,” Joy adds.

Configured in this way, the antenna could be used to explore the fundamentals of biology as natural processes occur, Sarkar says. Instead of destroying cells to examine their cytoplasm as is typically done, the Cell Rover could monitor the development or division of a cell, detecting different chemicals and biomolecules such as enzymes, or physical changes such as in cell pressure — all in real-time and in vivo.

Materials such as polymers that undergo change in mass or stress in response to chemical or biomolecular changes — already used in medical and other research — could be integrated with the operation of the Cell Rover, according to the researchers. Such an integration could provide insights not afforded by the current observational techniques that involve destruction of the cell.

With such capabilities, the Cell Rovers could be valuable in cancer and neurodegenerative disease research, for example. As Sarkar explains, the technology could be used to detect and monitor biochemical and electrical changes associated with the disease over its progression in individual cells. Applied in the field of drug discovery, the technology could illuminate the reactions of live cells to different drugs.

Because of the sophistication and scale of nanoelectronic devices such as transistors and switches — “representing five decades of tremendous advancements in the field of information technology,” Sarkar says — the Cell Rover, with its mini antenna, could carry out functions ranging all the way to intracellular computing and information processing for autonomous exploration and modulation of the cell. The research demonstrated that multiple Cell Rovers can be engaged, even within a single cell, to communicate among themselves and outside of the cells.

“The Cell Rover is an innovative concept as it can embed sensing, communication and information technology inside a living cell,” says Anantha P. Chandrakasan, dean of the MIT School of Engineering and the Vannevar Bush Professor of Electrical Engineering and Computer Science. “This opens up unprecedented opportunities for extremely precise diagnostics, therapeutics, and drug discovery, as well as creating a new direction at intersection between biology and electronic devices.”

Nanoparticle-modified microrobots for in vivo antibiotic delivery to treat acute bacterial pneumonia

by Liangfang Zhang in Nature Materials

Nanoengineers at the University of California San Diego have developed microscopic robots, called microrobots, that can swim around in the lungs, deliver medication and be used to clear up life-threatening cases of bacterial pneumonia.

In mice, the microrobots safely eliminated pneumonia-causing bacteria in the lungs and resulted in 100% survival. By contrast, untreated mice all died within three days after infection.

The microrobots are made of algae cells whose surfaces are speckled with antibiotic-filled nanoparticles. The algae provide movement, which allows the microrobots to swim around and deliver antibiotics directly to more bacteria in the lungs. The nanoparticles containing the antibiotics are made of tiny biodegradable polymer spheres that are coated with the cell membranes of neutrophils, which are a type of white blood cell. What’s special about these cell membranes is that they absorb and neutralize inflammatory molecules produced by bacteria and the body’s immune system. This gives the microrobots the ability to reduce harmful inflammation, which in turn makes them more effective at fighting lung infection.

The work is a joint effort between the labs of nanoengineering professors Joseph Wang and Liangfang Zhang, both at the UC San Diego Jacobs School of Engineering. Wang is a world leader in the field of micro- and nanorobotics research, while Zhang is a world leader in developing cell-mimicking nanoparticles for treating infections and diseases. Together, they have pioneered the development of tiny drug-delivering robots that can be safely used in live animals to treat bacterial infections in the stomach and blood. Treating bacterial lung infections is the latest in their line of work.

“Our goal is to do targeted drug delivery into more challenging parts of the body, like the lungs. And we want to do it in a way that is safe, easy, biocompatible and long lasting,” said Zhang. “That is what we’ve demonstrated in this work.”

The team used the microrobots to treat mice with an acute and potentially fatal form of pneumonia caused by the bacteria Pseudomonas aeruginosa. This form of pneumonia commonly affects patients who receive mechanical ventilation in the intensive care unit. The researchers administered the microrobots to the lungs of the mice through a tube inserted in the windpipe. The infections fully cleared up after one week. All mice treated with the microrobots survived past 30 days, while untreated mice died within three days.

Treatment with the microrobots was also more effective than an IV injection of antibiotics into the bloodstream. The latter required a dose of antibiotics that was 3000 times higher than that used in the microrobots to achieve the same effect. For comparison, a dose of microrobots provided 500 nanograms of antibiotics per mouse, while an IV injection provided 1.644 milligrams of antibiotics per mouse.

The team’s approach is so effective because it puts the medication right where it needs to go rather than diffusing it through the rest of the body.

“These results show how targeted drug delivery combined with active movement from the microalgae improves therapeutic efficacy,” said Wang.

“With an IV injection, sometimes only a very small fraction of antibiotics will get into the lungs. That’s why many current antibiotic treatments for pneumonia don’t work as well as needed, leading to very high mortality rates in the sickest patients,” said Victor Nizet, professor at UC San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences, who is a co-author on the study and a physician-scientist collaborator of Wang and Zhang. “Based on these mouse data, we see that the microrobots could potentially improve antibiotic penetration to kill bacterial pathogens and save more patients’ lives.”

And if the thought of putting algae cells in your lungs makes you squeamish, the researchers say that this approach is safe. After treatment, the body’s immune cells efficiently digest the algae, along with any remaining nanoparticles. “Nothing toxic is left behind,” said Wang.

The work is still at the proof-of-concept stage. The team plans to do more basic research to understand exactly how the microrobots interact with the immune system. The next steps also include studies to validate the microrobot treatment and scaling it up before testing it in larger animals and eventually, in humans.

“We’re pushing the boundary further in the field of targeted drug delivery,” said Zhang.

Nanophotonic control of thermal emission under extreme temperatures in air

by Sean McSherry et al in Nature Nanotechnology

A new nanophotonic material has broken records for high-temperature stability, potentially ushering in more efficient electricity production and opening a variety of new possibilities in the control and conversion of thermal radiation.

Developed by a University of Michigan-led team of chemical and materials science engineers, the material controls the flow of infrared radiation and is stable at temperatures of 2,000 degrees Fahrenheit in air, a nearly twofold improvement over existing approaches.

The material uses a phenomenon called destructive interference to reflect infrared energy while letting shorter wavelengths pass through. This could potentially reduce heat waste in thermophotovoltaic cells, which convert heat into electricity but can’t use infrared energy, by reflecting infrared waves back into the system. The material could also be useful in optical photovoltaics, thermal imaging, environmental barrier coatings, sensing, camouflage from infrared surveillance devices and other applications.

“It’s similar to the way butterfly wings use wave interference to get their color. Butterfly wings are made up of colorless materials, but those materials are structured and patterned in a way that absorbs some wavelengths of white light but reflects others, producing the appearance of color,” said Andrej Lenert, U-M assistant professor of chemical engineering and co-corresponding author of the study in Nature Nanotechnology.

“This material does something similar with infrared energy. The challenging part has been preventing breakdown of that color-producing structure under high heat.”

The approach is a major departure from the current state of engineered thermal emitters, which typically use foams and ceramics to limit infrared emissions. These materials are stable at high temperature but offer very limited control over which wavelengths they let through. Nanophotonics could offer much more tunable control, but past efforts haven’t been stable at high temperatures, often melting or oxidizing (the process that forms rust on iron). In addition, many nanophotonic materials only maintain their stability in a vacuum.

The new material works toward solving that problem, besting the previous record for heat resistance among air-stable photonic crystals by more than 900 degrees Fahrenheit in open air. In addition, the material is tunable, enabling researchers to tweak it to modify energy for a wide variety of potential applications. The research team predicted that applying this material to existing TPVs will increase efficiency by 10% and believes that much greater efficiency gains will be possible with further optimization.

The team developed the solution by combining chemical engineering and materials science expertise. Lenert’s chemical engineering team began by looking for materials that wouldn’t mix even if they started to melt.

“The goal is to find materials that will maintain nice, crisp layers that reflect light in the way we want, even when things get very hot,” Lenert said. “So we looked for materials with very different crystal structures, because they tend not to want to mix.”

They hypothesized that a combination of rock salt and perovskite, a mineral made of calcium and titanium oxides, fit the bill. Collaborators at U-M and the University of Virginia ran supercomputer simulations to confirm that the combination was a good bet.

John Heron, co-corresponding author of the study and an assistant professor of materials science and engineering at U-M, and Matthew Webb, a doctoral student in materials science and engineering, then carefully deposited the material using pulsed laser deposition to achieve precise layers with smooth interfaces. To make the material even more durable, they used oxides rather than conventional photonic materials; the oxides can be layered more precisely and are less likely to degrade under high heat.

“In previous work, traditional materials oxidized under high heat, losing their orderly layered structure,” Heron said. “But when you start out with oxides, that degradation has essentially already taken place. That produces increased stability in the final layered structure.”

After testing confirmed that the material worked as designed, Sean McSherry, first author of the study and a doctoral student in materials science and engineering at U-M, used computer modeling to identify hundreds of other combinations of materials that are also likely to work. While commercial implementation of the material tested in the study is likely years away, the core discovery opens up a new line of research into a variety of other nanophotonic materials that could help future researchers develop a range of new materials for a variety of applications.

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