Tag Archives: Japan

Nanomesh for hypoallergenic wearable electronics

It stands to reason that sensors and monitoring devices held against the skin (wearable electronics) for long periods of time could provoke an allergic reaction. Scientists at the University of Tokyo have devised a possible solution according to a July 17, 2017 news item on ScienceDaily,

A hypoallergenic electronic sensor can be worn on the skin continuously for a week without discomfort, and is so light and thin that users forget they even have it on, says a Japanese group of scientists. The elastic electrode constructed of breathable nanoscale meshes holds promise for the development of noninvasive e-skin devices that can monitor a person’s health continuously over a long period.

Here’s an image illustrating the hypoallergenic electronics,

Caption: The electric current from a flexible battery placed near the knuckle flows through the conductor and powers the LED just below the fingernail. Credit: 2017 Someya Laboratory.

A University of Tokyo press release on EurekAlert, which originated the news item, expands on the theme,

Wearable electronics that monitor heart rate and other vital health signals have made headway in recent years, with next-generation gadgets employing lightweight, highly elastic materials attached directly onto the skin for more sensitive, precise measurements. However, although the ultrathin films and rubber sheets used in these devices adhere and conform well to the skin, their lack of breathability is deemed unsafe for long-term use: dermatological tests show the fine, stretchable materials prevent sweating and block airflow around the skin, causing irritation and inflammation, which ultimately could lead to lasting physiological and psychological effects.

“We learned that devices that can be worn for a week or longer for continuous monitoring were needed for practical use in medical and sports applications,” says Professor Takao Someya at the University of Tokyo’s Graduate School of Engineering whose research group had previously developed an on-skin patch that measured oxygen in blood.

In the current research, the group developed an electrode constructed from nanoscale meshes containing a water-soluble polymer, polyvinyl alcohol (PVA), and a gold layer–materials considered safe and biologically compatible with the body. The device can be applied by spraying a tiny amount of water, which dissolves the PVA nanofibers and allows it to stick easily to the skin–it conformed seamlessly to curvilinear surfaces of human skin, such as sweat pores and the ridges of an index finger’s fingerprint pattern.

The researchers next conducted a skin patch test on 20 subjects and detected no inflammation on the participants’ skin after they had worn the device for a week. The group also evaluated the permeability, with water vapor, of the nanomesh conductor–along with those of other substrates like ultrathin plastic foil and a thin rubber sheet–and found that its porous mesh structure exhibited superior gas permeability compared to that of the other materials.

Furthermore, the scientists proved the device’s mechanical durability through repeated bending and stretching, exceeding 10,000 times, of a conductor attached on the forefinger; they also established its reliability as an electrode for electromyogram recordings when its readings of the electrical activity of muscles were comparable to those obtained through conventional gel electrodes.

“It will become possible to monitor patients’ vital signs without causing any stress or discomfort,” says Someya about the future implications of the team’s research. In addition to nursing care and medical applications, the new device promises to enable continuous, precise monitoring of athletes’ physiological signals and bodily motion without impeding their training or performance.

Here’s a link to and a citation for the paper,

Inflammation-free, gas-permeable, lightweight, stretchable on-skin electronics with nanomeshes by Akihito Miyamoto, Sungwon Lee, Nawalage Florence Cooray, Sunghoon Lee, Mami Mori, Naoji Matsuhisa, Hanbit Jin, Leona Yoda, Tomoyuki Yokota, Akira Itoh, Masaki Sekino, Hiroshi Kawasaki, Tamotsu Ebihara, Masayuki Amagai, & Takao Someya. Nature Nanotechnology (2017) doi:10.1038/nnano.2017.125 Published online 17 July 2017

This paper is behind a paywall.

Stellar’s jay gives structural colo(u)r a new look

The structural colo(u)r stories I’ve posted previously identify nanostructures as the reason for why certain animals and plants display a particular set of optical properties, colours that can’t be obtained by pigment or dye. However, the Stellar’s jay structural colour story is a little different.

Caption: Bio-inspired bright structurally colored colloidal amorphous array enhanced by controlling thickness and black background. ©Yukikazu Takeoka

From a May 8, 2017 news item on ScienceDaily,

A Nagoya University-led [Japan] research team mimics the rich color of bird plumage and demonstrates new ways to control how light interacts with materials.

Bright colors in the natural world often result from tiny structures in feathers or wings that change the way light behaves when it’s reflected. So-called “structural color” is responsible for the vivid hues of birds and butterflies. Artificially harnessing this effect could allow us to engineer new materials for applications such as solar cells and chameleon-like adaptive camouflage.

Inspired by the deep blue coloration of a native North American bird, Stellar’s jay, a team at Nagoya University reproduced the color in their lab, giving rise to a new type of artificial pigment. This development was reported in Advanced Materials.

“The Stellar’s jay’s feathers provide an excellent example of angle-independent structural color,” says last author Yukikazu Takeoka, “This color is enhanced by dark materials, which in this case can be attributed to black melanin particles in the feathers.

A May 8, 2017 Nagoya University press release (also on EurekAlert), which originated the news item, expands on the theme of what makes the structural colour of a Stellar’s jay feather different,

In most cases, structural colors appear to change when viewed from different perspectives. For example, imagine the way that the colors on the underside of a CD appear to shift when the disc is viewed from a different angle. The difference in Stellar’s jay’s blue is that the structures, which interfere with light, sit on top of black particles that can absorb a part of this light. This means that at all angles, however you look at it, the color of the Stellar’s Jay does not change.

The team used a “layer-by-layer” approach to build up films of fine particles that recreated the microscopic sponge-like texture and black backing particles of the bird’s feathers.

To mimic the feathers, the researchers covered microscopic black core particles with layers of even smaller transparent particles, to make raspberry-like particles. The size of the core and the thickness of the layers controlled the color and saturation of the resulting pigments. Importantly, the color of these particles did not change with viewing angle.

“Our work represents a much more efficient way to design artificially produced angle-independent structural colors,” Takeoka adds. “We still have much to learn from biological systems, but if we can understand and successfully apply these phenomena, a whole range of new metamaterials will be accessible for all kinds of advanced applications where interactions with light are important.”

Here’s a link to and a citation for the paper,

Bio-Inspired Bright Structurally Colored Colloidal Amorphous Array Enhanced by Controlling Thickness and Black Background by Masanori Iwata, Midori Teshima, Takahiro Seki, Shinya Yoshioka, and Yukikazu Takeoka. Advanced Materials DOI: 10.1002/adma.201605050 Version of Record online: 26 APR 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Ordinarily, I’d expect to see the term ‘nano’ somewhere in the press release or in the abstract but that’s not the case here. The best I could find was a reference to ‘submicrometer-sized .. particles” in the abstract. I suppose that could refer to the nanoscale but given that a Japanese researcher (Norio Taniguchi in 1974) coined the phrase ‘nanotechnology’ to describe research at that scale it seems unlikely that Japanese researchers some forty years later wouldn’t use that term when appropriate.

Controlling the nanostructure of inorganic materials with tumor suppressor proteins

A May 3, 2017 news item on Nanowerk announces research from Japan on using tumor suppressor proteins to control nanostructures,

A new method combining tumor suppressor protein p53 and biomineralization peptide BMPep successfully created hexagonal silver nanoplates, suggesting an efficient strategy for controlling the nanostructure of inorganic materials.

Precise control of nanostructures is a key factor to form functional nanomaterials. Biomimetic approaches are considered effective for fabricating nanomaterials because biomolecules are able to bind with specific targets, self-assemble, and build complex structures. Oligomerization, or the assembly of biomolecules, is a crucial aspect of natural materials that form higher-ordered structures.

A May 3,2017 Hokkaido University research press release, which originated the news item, delves into the details,

Some peptides are known to bind with a specific inorganic substance, such as silver, and enhance its crystal formation. This phenomenon, called peptide-mediated biomineralization, could be used as a biomimetic approach to create functional inorganic structures. Controlling the spatial orientation of the peptides could yield complex inorganic structures, but this has long been a great challenge.

A team of researchers led by Hokkaido University Professor Kazuyasu Sakaguchi has succeeded in controlling the oligomerization of the silver biomineralization peptide (BMPep) which led to the creation of hexagonal silver nanoplates.

The team utilized the well-known tumor suppressor protein p53 which has been known to form tetramers through its tetramerization domain (p53Tet). “The unique symmetry of the p53 tetramer is an attractive scaffold to be used in controlling the overall oligomerization state of the silver BMPep such as its spatial orientation, geometry, and valency,” says Sakaguchi.

In the experiments, the team successfully created silver BMPep fused with p53Tet. This resulted in the formation of BMPep tetramers which yielded hexagonal silver nanoplates. They also found that the BMPep tetramers have enhanced specificity to the structured silver surface, apparently regulating the direction of crystal growth to form hexagonal nanoplates. Furthermore, the tetrameric peptide acted as a catalyst, controlling the silver’s crystal growth without consuming the peptide.

“Our novel method can be applied to other biomineralization peptides and oligomerization proteins, thus providing an efficient and versatile strategy for controlling nanostructures of various inorganic materials. The production of tailor-made nanomaterials is now more feasible,” Sakaguchi commented.

monomeric and tetrameric biomineralization peptides

(Left panels) Schematic illustrations of monomeric and tetrameric biomineralization peptides fused with p53Tet and electron microscopy images of silver nanostructures formed by the biomineralization peptides. Scale bar = 100 nm. (Right) The proposed model in which tetrameric biomineralization peptides regulate the direction of crystal growth and therefore its nanostructure.

Here’s a link to and a citation for the paper,

Oligomerization enhances the binding affinity of a silver biomineralization peptide and catalyzes nanostructure formation by Tatsuya Sakaguchi, Jose Isagani B. Janairo, Mathieu Lussier-Price, Junya Wada, James G. Omichinski, & Kazuyasu Sakaguchi. Scientific Reports 7, Article number: 1400 (2017)  doi:10.1038/s41598-017-01442-8 Published online: 03 May 2017

This paper is open access.

Off to the Nanocar Race: April 28, 2017

The Nanocar Race (which at one point was the NanoCar Race) took place on April 28 -29, 2017 in Toulouse, France. Presumably the fall 2016 race did not take place (as I had reported in my May 26, 2016 posting). A March 23, 2017 news item on ScienceDaily gave the latest news about the race,

Nanocars will compete for the first time ever during an international molecule-car race on April 28-29, 2017 in Toulouse (south-western France). The vehicles, which consist of a few hundred atoms, will be powered by minute electrical pulses during the 36 hours of the race, in which they must navigate a racecourse made of gold atoms, and measuring a maximum of a 100 nanometers in length. They will square off beneath the four tips of a unique microscope located at the CNRS’s Centre d’élaboration de matériaux et d’études structurales (CEMES) in Toulouse. The race, which was organized by the CNRS, is first and foremost a scientific and technological challenge, and will be broadcast live on the YouTube Nanocar Race channel. Beyond the competition, the overarching objective is to advance research in the observation and control of molecule-machines.

More than just a competition, the Nanocar Race is an international scientific experiment that will be conducted in real time, with the aim of testing the performance of molecule-machines and the scientific instruments used to control them. The years ahead will probably see the use of such molecular machinery — activated individually or in synchronized fashion — in the manufacture of common machines: atom-by-atom construction of electronic circuits, atom-by-atom deconstruction of industrial waste, capture of energy…The Nanocar Race is therefore a unique opportunity for researchers to implement cutting-edge techniques for the simultaneous observation and independent maneuvering of such nano-machines.

The experiment began in 2013 as part of an overview of nano-machine research for a scientific journal, when the idea for a car race took shape in the minds of CNRS senior researcher Christian Joachim (now the director of the race) and Gwénaël Rapenne, a Professor of chemistry at Université Toulouse III — Paul Sabatier. …

An April 19, 2017 article by Davide Castelvecchi for Nature (magazine) provided more detail about the race (Note: Links have been removed),

The term nanocar is actually a misnomer, because the molecules involved in this race have no motors. (Future races may incorporate them, Joachim says.) And it is not clear whether the molecules will even roll along like wagons: a few designs might, but many lack axles and wheels. Drivers will use electrons from the tip of a scanning tunnelling microscope (STM) to help jolt their molecules along, typically by just 0.3 nano-metres each time — making 100 nanometres “a pretty long distance”, notes physicist Leonhard Grill of the University of Graz, Austria, who co-leads a US–Austrian team in the race.

Contestants are not allowed to directly push on their molecules with the STM tip. Some teams have designed their molecules so that the incoming electrons raise their energy states, causing vibrations or changes to molecular structures that jolt the racers along. Others expect electrostatic repulsion from the electrons to be the main driving force. Waka Nakanishi, an organic chemist at the National Institute for Materials Science in Tsukuba, Japan, has designed a nanocar with two sets of ‘flaps’ that are intended to flutter like butterfly wings when the molecule is energized by the STM tip (see ‘Molecular race’). Part of the reason for entering the race, she says, was to gain access to the Toulouse lab’s state-of-the-art STM to better understand the molecule’s behaviour.

Eric Masson, a chemist at Ohio University in Athens, hopes to find out whether the ‘wheels’ (pumpkin-shaped groups of atoms) of his team’s car will roll on the surface or simply slide. “We want to better understand the nature of the interaction between the molecule and the surface,” says Masson..

Adapted from www.nanocar-race.cnrs.fr

Simply watching the race progress is half the battle. After each attempted jolt, teams will take three minutes to scan their race track with the STM, and after each hour they will produce a short animation that will immediately be posted online. That way, says Joachim, everyone will be able to see the race streamed almost live.

Nanoscale races

The Toulouse laboratory has an unusual STM with four scanning tips — most have only one — that will allow four teams to race at the same time, each on a different section of the gold surface. Six teams will compete this week to qualify for one of the four spots; the final race will begin on 28 April at 11 a.m. local time. The competitors will face many obstacles during the contest. Individual molecules in the race will often be lost or get stuck, and the trickiest part may be to negotiate the two turns in the track, Joachim says. He thinks the racers may require multiple restarts to cover the distance.

For anyone who wants more information, go to the Nanocar Race website. There is also a highlights video,

Published on Apr 29, 2017

The best moments of the first-ever international race of molecule- cars.

An easier way to make highly ordered porous films for commercial sensors

An April 3, 2017 news item on Nanowerk describes Japanese research into a new technique for producing MOF’s (metallic organic frameworks),

Osaka-based researchers developed a new method to create films of porous metal–organic frameworks fully aligned on inorganic substrates. The method is simple, requiring only that the substrate and an organic linker are mixed under mild conditions, and fast, producing perfectly aligned films within minutes. The films oriented fluorescent dye molecules within their pores, and the fluorescence response of these dyes was switched on or off simply by rotating the material in polarized light.

An April 3, 2017 Osaka University press release on the Alpha Gallileo news service, which originated the news item, explains more about MOFs and gives some details about the new technique,,

Metal–organic frameworks, or MOFs, are highly ordered crystalline structures made of metal ion nodes and organic molecule linkers. Many MOFs can take up and store gases, such as carbon dioxide or hydrogen, thanks to their porous, sponge-like structures.

MOFs are also potential chemical sensors. They can be designed to change color or display another optical signal if a particular molecule is taken up into the framework. However, most studies on MOFs are performed on tiny single crystals, which is not practical for the commercial development of these materials.

Chemists have now come a step closer to making commercially viable sensors that contain highly ordered MOFs, thanks to the collaboration of an international team of researchers at Osaka Prefecture University, Osaka University and Graz University of Technology. The method will allow researchers to fabricate large tailor-made MOF films on any substrate of any size, which will vastly improve their prospects for commercial development.

In a study recently published in Nature Materials and highlighted on the cover and in the ‘News and Views’ section of the journal, the Osaka-based researchers report a one-step method to prepare thin MOF films directly on inorganic copper hydroxide substrates. Using this method, the researchers produced large MOF films with areas of more than 1 cm2 that were, for the first time, fully aligned with the crystal lattice of the underlying substrate.

Noting that microcrystals of copper hydroxide can be converted into MOFs by adding organic linker molecules under mild conditions, the researchers used the same strategy to create a thin MOF layer on larger copper hydroxide substrates. They carefully chose the carboxylic acid-based linker molecule 1,4-dibenzenedicarboxylic acid because it fit exactly to the spacing between the copper atoms on the substrate surface.

A MOF film began to grow on the copper hydroxide substrates within minutes of mixing it with the linker molecule, making this technique much easier and faster than previous step-wise approaches to build up MOF films. Using microscopy and X-ray diffraction techniques, the researchers found that the film was precisely oriented along the copper hydroxide lattice.

To demonstrate the unique optical behavior of their films, the researchers filled the MOF’s ordered pores with fluorescent molecules, which fluoresce when light is shone on them in a particular direction. When they shone polarized light on the ordered material, the researchers found that they could easily switch the fluorescence response on or off simply by rotating the material.

Here’s a link to and a citation for the paper,

Centimetre-scale micropore alignment in oriented polycrystalline metal–organic framework films via heteroepitaxial growth by Paolo Falcaro, Kenji Okada, Takaaki Hara, Ken Ikigaki, Yasuaki Tokudome, Aaron W. Thornton, Anita J. Hill, Timothy Williams, Christian Doonan, & Masahide Takahashi. Nature Materials 16, 342–348  (2017) doi:10.1038/nmat4815 Published online 05 December 2016

This paper is behind a paywall.

A new platform for culturing stem cells: a Multiplexed Artificial Cellular Microenvironment array

Japanese scientists have developed a more precise method for culturing stem cells according to a March 14, 2017 news item on Nanowerk,

A team of researchers in Japan has developed a new platform for culturing human pluripotent stem cells that provides far more control of culture conditions than previous tools by using micro and nanotechnologies.

The Multiplexed Artificial Cellular Microenvironment (MACME) array places nanofibres, mimicking cellular matrices, into fluid-filled micro-chambers of precise sizes, which mimic extracellular environments.

Caption: The Multiplexed Artificial Cellular Microenvironment (MACME) array, consisted with a microfluidic structure and nanofibre array for mimicking cellular microenvironments. Credit: Kyoto University iCeMS

A March 17, 2017 Kyoto University press release (also on EurekAlert), which originated the news item, explains the research in more detail,

Human pluripotent stems cells (hPSCs) hold great promise for tissue engineering, regenerative medicine and cell-based therapies because they can become any type of cell. The environment surrounding the cells plays a major role in determining what tissues they become, if they replicate into more cells, or die. However, understanding these interactions has been difficult because researchers have lacked tools that work on the appropriate scale.

Often, stem cells are cultured in a cell culture medium in small petri dishes. While factors such as medium pH levels and nutrients can be controlled, the artificial set up is on the macroscopic scale and does not allow for precise control of the physical environment surrounding the cells.

The MACME array miniaturizes this set up, culturing stem cells in rows of micro-chambers of cell culture medium. It also takes it a step further by placing nanofibers in these chambers to mimic the structures found around cells.

Led by Ken-ichiro Kamei of Kyoto University’s Institute for Integrated Cell-Material Sciences (iCeMS), the team tested a variety of nanofiber materials and densities, micro-chamber heights and initial stem cell densities to determine the best combination that encourages human pluripotent stem cells to replicate.

They stained the cells with several fluorescent markers and used a microscope to see if the cells died, replicated or differentiated into tissues.

Their analysis revealed that gelatin nanofibers and medium-sized chambers that create medium seed cell density provided the best environment for the stem cells to continue to multiply. The quantity and density of neighboring cells strongly influences cell survival.

The array is an “optimal and powerful approach for understanding how environmental cues regulate cellular functions,” the researchers conclude in a recently published paper in the journal Small.

This array appears to be the first time multiple kinds of extracellular environments can be mounted onto a single device, making it much easier to compare how different environments influence cells.

The MACME array could substantially reduce experiment costs compared to conventional tools, in part because it is low volume and requires less cell culture medium. The array does not require any special equipment and is compatible with both commonly used laboratory pipettes and automated pipette systems for performing high-throughput screening.

Here’s a link to and a citation for the paper,

Microfluidic-Nanofiber Hybrid Array for Screening of Cellular Microenvironments by Ken-ichiro Kamei, Yasumasa Mashimo, Momoko Yoshioka, Yumie Tokunaga, Christopher Fockenberg, Shiho Terada, Yoshie Koyama, Minako Nakajima, Teiko Shibata-Seki, Li Liu, Toshihiro Akaike, Eiry Kobatake, Siew-Eng How, Motonari Uesugi, and Yong Chen. Small DOI: 10.1002/smll.201603104 Version of Record online: 8 MAR 2017

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Nanozymes as an antidote for pesticides

Should you have concerns about exposure to pesticides or chemical warfare agents (timely given events in Syria as per this April 4, 2017 news item on CBC [Canadian Broadcasting News Corporation] online) , scientists at the Lomonosov Moscow State University have developed a possible antidote according to a March 8,, 2017 news item on phys.org,

Members of the Faculty of Chemistry of the Lomonosov Moscow State University have developed novel nanosized agents that could be used as efficient protective and antidote modalities against the impact of neurotoxic organophosphorus compounds such as pesticides and chemical warfare agents. …

A March 7, 2017 Lomonosov Moscow State University press release on EurekAlert, which originated the news item, describes the work in detail,

A group of scientists from the Faculty of Chemistry under the leadership of Prof. Alexander Kabanov has focused their research supported by a “megagrant” on the nanoparticle-based delivery to an organism of enzymes, capable of destroying toxic organophosphorous compounds. Development of first nanosized drugs has started more than 30 years ago and already in the 90-s first nanomedicines for cancer treatment entered the market. First such medicines were based on liposomes – spherical vesicles made of lipid bilayers. The new technology, developed by Kabanov and his colleagues, uses an enzyme, synthesized at the Lomonosov Moscow State University, encapsulated into a biodegradable polymer coat, based on an amino acid (glutamic acid).

Alexander Kabanov, Doctor of Chemistry, Professor at the Eshelman School of Pharmacy of the University of North Carolina (USA) and the Faculty of Chemistry, M. V. Lomonosov Moscow State University, one of the authors of the article explains: “At the end of the 80-s my team (at that time in Moscow) and independently Japanese colleagues led by Prof. Kazunori Kataoka from Tokyo began using polymer micelles for small molecules delivery. Soon the nanomedicine field has “exploded”. Currently hundreds of laboratories across the globe work in this area, applying a wide variety of approaches to creation of such nanosized agents. A medicine on the basis of polymeric micelles, developed by a Korean company Samyang Biopharm, was approved for human use in 2006.”

Professor Kabanov’s team after moving to the USA in 1994 focused on development of polymer micelles, which could include biopolymers due to electrostatic interactions. Initially chemists were interested in usage of micelles for RNA and DNA delivery but later on scientists started actively utilizing this approach for delivery of proteins and, namely, enzymes, to the brain and other organs.

Alexander Kabanov says: “At the time I worked at the University of Nebraska Medical Center, in Omaha (USA) and by 2010 we had a lot of results in this area. That’s why when my colleague from the Chemical Enzymology Department of the Lomonosov Moscow State University, Prof. Natalia Klyachko offered me to apply for a megagrant the research theme of the new laboratory was quite obvious. Specifically, to use our delivery approach, which we’ve called a “nanozyme”, for “improvement” of enzymes, developed by colleagues at the Lomonosov Moscow State University for its further medical application.”

Scientists together with the group of enzymologists from the Lomonosov Moscow State University under the leadership of Elena Efremenko, Doctor of Biological Sciences, have chosen organophosphorus hydrolase as a one of the delivered enzymes. Organophosphorus hydrolase is capable of degrading toxic pesticides and chemical warfare agents with very high rate. However, it has disadvantages: because of its bacterial origin, an immune response is observed as a result of its delivery to an organism of mammals. Moreover, organophosphorus hydrolase is quickly removed from the body. Chemists have solved this problem with the help of a “self-assembly” approach: as a result of inclusion of organophosphorus hydrolase enzyme in a nanozyme particles the immune response becomes weaker and, on the contrary, both the storage stability of the enzyme and its lifetime after delivery to an organism considerably increase. Rat experiments have proved that such nanozyme efficiently protects organisms against lethal doses of highly toxic pesticides and even chemical warfare agents, such as VX nerve gas.

Alexander Kabanov summarizes: “The simplicity of our approach is very important. You could get an organophosphorus hydrolase nanozyme by simple mixing of aqueous solutions of anenzyme and safe biocompatible polymer. This nanozyme is self-assembled due to electrostatic interaction between a protein (enzyme) and polymer”.

According to the scientist’s words the simplicity and technological effectiveness of the approach along with the obtained promising results of animal experiments bring hope that this modality could be successful and in clinical use.

Members of the Faculty of Chemistry of the Lomonosov Moscow State University, along with scientists from the 27th Central Research Institute of the Ministry of Defense of the Russian Federation, the Eshelman School of Pharmacy of the University of North Carolina at Chapel Hill (USA) and the University of Nebraska Medical Center (UNC) have taken part in the Project.

Here’s a link to and a citation for the paper,

A simple and highly effective catalytic nanozyme scavenger for organophosphorus neurotoxins by Elena N. Efremenko, Ilya V. Lyagin, Natalia L. Klyachko, Tatiana Bronich, Natalia V. Zavyalova, Yuhang Jiang, Alexander V. Kabanov. Journal of Controlled Release Volume 247, 10 February 2017, Pages 175–181  http://dx.doi.org/10.1016/j.jconrel.2016.12.037

This paper is behind a paywall.

Matrix of gelatin nanofibres for culturing large quantities of human stem cells

A Feb. 14, 2017 news item on ScienceDaily describes work that may have a big influence on stem cell production,

A new nanofiber-on-microfiber matrix could help produce more and better quality stem cells for disease treatment and regenerative therapies.

A matrix made of gelatin nanofibers on a synthetic polymer microfiber mesh may provide a better way to culture large quantities of healthy human stem cells.

Developed by a team of researchers led by Ken-ichiro Kamei of Kyoto University’s Institute for Integrated Cell-Material Sciences (iCeMS), the ‘fiber-on-fiber’ (FF) matrix improves on currently available stem cell culturing techniques.

A Feb. 14/15, 2017 Kyoto University press release (also on EurekAlert), which originated the news item, explains why scientists are trying to find a new way to culture stem cells,

Researchers have been developing 3D culturing systems to allow human pluripotent stem cells (hPSCs) to grow and interact with their surroundings in all three dimensions, as they would inside the human body, rather than in two dimensions, like they do in a petri dish.

Pluripotent stem cells have the ability to differentiate into any type of adult cell and have huge potential for tissue regeneration therapies, treating diseases, and for research purposes.

Most currently reported 3D culturing systems have limitations, and result in low quantities and quality of cultured cells.

Kamei and his colleagues fabricated gelatin nanofibers onto a microfiber sheet made of synthetic, biodegradable polyglycolic acid. Human embryonic stem cells were then seeded onto the matrix in a cell culture medium.

The FF matrix allowed easy exchange of growth factors and supplements from the culture medium to the cells. Also, the stem cells adhered well to the matrix, resulting in robust cell growth: after four days of culture, more than 95% of the cells grew and formed colonies.

The team also scaled up the process by designing a gas-permeable cell culture bag in which multiple cell-loaded, folded FF matrices were placed. The system was designed so that minimal changes were needed to the internal environment, reducing the amount of stress placed on the cells. This newly developed system yielded a larger number of cells compared to conventional 2D and 3D culture methods.

“Our method offers an efficient way to expand hPSCs of high quality within a shorter term,” write the researchers in their study published in the journal Biomaterials. Also, because the use of the FF matrix is not limited to a specific type of culture container, it allows for scaling up production without loss of cell functions. “Additionally, as nanofiber matrices are advantageous for culturing other adherent cells, including hPSC-derived differentiated cells, FF matrix might be applicable to the large-scale production of differentiated functional cells for various applications,” the researchers conclude.

Human stem cells that grew on the ‘fiber-on-fiber’ culturing system

Here’s a link to and a citation for the paper,

Nano-on-micro fibrous extracellular matrices for scalable expansion of human ES/iPS cells by Li Liu, Ken-ichiro Kamei, Momoko Yoshioka, Minako Nakajima, Junjun Li, Nanae Fujimoto, Shiho Terada, Yumie Tokunaga, Yoshie Koyama, Hideki Sato, Kouichi Hasegawa. Biomaterials Volume 124, April 2017, Pages 47–54  http://dx.doi.org/10.1016/j.biomaterials.2017.01.039

This paper is behind a paywall.

Ishiguro’s robots and Swiss scientist question artificial intelligence at SXSW (South by Southwest) 2017

It seems unexpected to stumble across presentations on robots and on artificial intelligence at an entertainment conference such as South by South West (SXSW). Here’s why I thought so, from the SXSW Wikipedia entry (Note: Links have been removed),

South by Southwest (abbreviated as SXSW) is an annual conglomerate of film, interactive media, and music festivals and conferences that take place in mid-March in Austin, Texas, United States. It began in 1987, and has continued to grow in both scope and size every year. In 2011, the conference lasted for 10 days with SXSW Interactive lasting for 5 days, Music for 6 days, and Film running concurrently for 9 days.

Lifelike robots

The 2017 SXSW Interactive featured separate presentations by Japanese roboticist, Hiroshi Ishiguro (mentioned here a few times), and EPFL (École Polytechnique Fédérale de Lausanne; Switzerland) artificial intelligence expert, Marcel Salathé.

Ishiguro’s work is the subject of Harry McCracken’s March 14, 2017 article for Fast Company (Note: Links have been removed),

I’m sitting in the Japan Factory pavilion at SXSW in Austin, Texas, talking to two other attendees about whether human beings are more valuable than robots. I say that I believe human life to be uniquely precious, whereupon one of the others rebuts me by stating that humans allow cars to exist even though they kill humans.

It’s a reasonable point. But my fellow conventioneer has a bias: It’s a robot itself, with an ivory-colored, mask-like face and visible innards. So is the third participant in the conversation, a much more human automaton modeled on a Japanese woman and wearing a black-and-white blouse and a blue scarf.

We’re chatting as part of a demo of technologies developed by the robotics lab of Hiroshi Ishiguro, based at Osaka University, and Japanese telecommunications company NTT. Ishiguro has gained fame in the field by creating increasingly humanlike robots—that is, androids—with the ultimate goal of eliminating the uncanny valley that exists between people and robotic people.

I also caught up with Ishiguro himself at the conference—his second SXSW—to talk about his work. He’s a champion of the notion that people will respond best to robots who simulate humanity, thereby creating “a feeling of presence,” as he describes it. That gives him and his researchers a challenge that encompasses everything from technology to psychology. “Our approach is quite interdisciplinary,” he says, which is what prompted him to bring his work to SXSW.

A SXSW attendee talks about robots with two robots.

If you have the time, do read McCracken’t piece in its entirety.

You can find out more about the ‘uncanny valley’ in my March 10, 2011 posting about Ishiguro’s work if you scroll down about 70% of the way to find the ‘uncanny valley’ diagram and Masahiro Mori’s description of the concept he developed.

You can read more about Ishiguro and his colleague, Ryuichiro Higashinaka, on their SXSW biography page.

Artificial intelligence (AI)

In a March 15, 2017 EPFL press release by Hilary Sanctuary, scientist Marcel Salathé poses the question: Is Reliable Artificial Intelligence Possible?,

In the quest for reliable artificial intelligence, EPFL scientist Marcel Salathé argues that AI technology should be openly available. He will be discussing the topic at this year’s edition of South by South West on March 14th in Austin, Texas.

Will artificial intelligence (AI) change the nature of work? For EPFL theoretical biologist Marcel Salathé, the answer is invariably yes. To him, a more fundamental question that needs to be addressed is who owns that artificial intelligence?

“We have to hold AI accountable, and the only way to do this is to verify it for biases and make sure there is no deliberate misinformation,” says Salathé. “This is not possible if the AI is privatized.”

AI is both the algorithm and the data

So what exactly is AI? It is generally regarded as “intelligence exhibited by machines”. Today, it is highly task specific, specially designed to beat humans at strategic games like Chess and Go, or diagnose skin disease on par with doctors’ skills.

On a practical level, AI is implemented through what scientists call “machine learning”, which means using a computer to run specifically designed software that can be “trained”, i.e. process data with the help of algorithms and to correctly identify certain features from that data set. Like human cognition, AI learns by trial and error. Unlike humans, however, AI can process and recall large quantities of data, giving it a tremendous advantage over us.

Crucial to AI learning, therefore, is the underlying data. For Salathé, AI is defined by both the algorithm and the data, and as such, both should be publicly available.

Deep learning algorithms can be perturbed

Last year, Salathé created an algorithm to recognize plant diseases. With more than 50,000 photos of healthy and diseased plants in the database, the algorithm uses artificial intelligence to diagnose plant diseases with the help of your smartphone. As for human disease, a recent study by a Stanford Group on cancer showed that AI can be trained to recognize skin cancer slightly better than a group of doctors. The consequences are far-reaching: AI may one day diagnose our diseases instead of doctors. If so, will we really be able to trust its diagnosis?

These diagnostic tools use data sets of images to train and learn. But visual data sets can be perturbed that prevent deep learning algorithms from correctly classifying images. Deep neural networks are highly vulnerable to visual perturbations that are practically impossible to detect with the naked eye, yet causing the AI to misclassify images.

In future implementations of AI-assisted medical diagnostic tools, these perturbations pose a serious threat. More generally, the perturbations are real and may already be affecting the filtered information that reaches us every day. These vulnerabilities underscore the importance of certifying AI technology and monitoring its reliability.

h/t phys.org March 15, 2017 news item

As I noted earlier, these are not the kind of presentations you’d expect at an ‘entertainment’ festival.

Peripheral nerves (a rat’s) regenerated when wrapped with nanomesh fiber

A Feb.28,2017 news item on Nanowerk announces a proposed nerve regeneration technique (Note: A link has been removed),

A research team consisting of Mitsuhiro Ebara, MANA associate principal investigator, Mechanobiology Group, NIMS, and Hiroyuki Tanaka, assistant professor, Orthopaedic Surgery, Osaka University Graduate School of Medicine, developed a mesh which can be wrapped around injured peripheral nerves to facilitate their regeneration and restore their functions (Acta Biomaterialia, “Electrospun nanofiber sheets incorporating methylcobalamin promote nerve regeneration and functional recovery in a rat sciatic nerve crush injury model”).

This mesh incorporates vitamin B12—a substance vital to the normal functioning of nervous systems—which is very soft and degrades in the body. When the mesh was applied to injured sciatic nerves in rats, it promoted nerve regeneration and recovery of their motor and sensory functions.

A Feb. 27, 2017 Japan National Institute for Materials Science (NIMS) press release for Osaka University, which originated the news item, provides more detail,

Artificial nerve conduits have been developed in the past to treat peripheral nerve injuries, but they merely form a cross-link to the injury site and do not promote faster nerve regeneration. Moreover, their application is limited to relatively few patients suffering from a complete loss of nerve continuity. Vitamin B12 has been known to facilitate nerve regeneration, but oral administration of it has not proven to be very effective, and no devices capable of delivering vitamin B12 directly to affected sites had been available. Therefore, it had been hoped to develop such medical devices to actively promote nerve regeneration in the many patients who suffer from nerve injuries but have not lost nerve continuity.

The NIMS-Osaka University joint research team recently developed a special mesh that can be wrapped around an injured nerve which releases vitamin B12 (methylcobalamin) until the injury heals. By developing very fine mesh fibers (several hundred nanometers in diameter) and reducing the crystallinity of the fibers, the team successfully created a very soft mesh that can be wrapped around a nerve. This mesh is made of a biodegradable plastic which, when implanted in animals, is eventually eliminated from the body. In fact, experiments demonstrated that application of the mesh directly to injured sciatic nerves in rats resulted in regeneration of axons and recovery of motor and sensory functions within six weeks.

The team is currently negotiating with a pharmaceutical company and other organizations to jointly study clinical application of the mesh as a medical device to treat peripheral nerve disorders, such as CTS.

This study was supported by the JSPS KAKENHI program (Grant Number JP15K10405) and AMED’s Project for Japan Translational and Clinical Research Core Centers (also known as Translational Research Network Program).

Figure 1. Conceptual diagram showing a nanofiber mesh incorporating vitamin B12 and its application to treat a peripheral nerve injury.

Here’s a link to and a citation for the paper,

Electrospun nanofiber sheets incorporating methylcobalamin promote nerve regeneration and functional recovery in a rat sciatic nerve crush injury model by Koji Suzuki, Hiroyuki Tanaka, Mitsuhiro Ebara, Koichiro Uto, Hozo Matsuoka, Shunsuke Nishimoto, Kiyoshi Okada, Tsuyoshi Murase, Hideki Yoshikawa. Acta Biomaterialia http://dx.doi.org/10.1016/j.actbio.2017.02.004 Available online 5 February 2017

This paper is behind a paywall.