Tag Archives: Shinshu University

An apple a day could help you clean up nanoplastics?

it’s really all about the pectin. From a June 27, 2022 Shinshu University (Japan) press release on EurekAlert (Note: A link has been removed),

Microplastics are known to collect in ecosystems and nanoplastics occur from the breaking down of microplastics. Nanoplastics are plastic particles of sizes less than 100nm and when they are in water, they are dispersed in a colloidal form. Nanoplastics might be more prevalent than microplastics, but it is hard to analyze and study in-depth due to their size. In zebrafish, however, nanoplastics have been found in various organs including the brain, which may be an indicator that it crosses the blood-brain barrier.

In towns and cities, 90% of microplastics are captured in the sewage treatment process. In the ocean, microplastics are also known to sink to the bottom by binding to biopolymers. Therefore, this research team at Shinshu University lead by Professor Hiroshi Moriwaki of the Department of Applied Biology, Faculty of Textile Science and Technology considered using pectin, a biopolymer to bind to nanoplastics with the help of Fe (III) or AI (III). They found that they were able to remove 95% of nanoplastics in the first 24 hours by using coagulating sedimentation with pectin and Fe(III) with filter paper.

The use of pectin was inspired by the abundance of apples in the prefecture of Nagano where Shinshu University is based. For more information, please read the paper, Interaction between nanoplastics and pectin, a water-soluble polysaccharide, in the presence of Fe(III) ion in the Journal of Environmental Chemical Engineering.

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

Interaction between nanoplastics and pectin, a water-soluble polysaccharide, in the presence of Fe(III) ion by Hiroshi Moriwaki, Naoya Komori, Yoshitake Akiyama. Journal of Environmental Chemical Engineering Volume 10, Issue 3, June 2022, 108054 Available online 9 June 2022, Version of Record 15 June 2022

This study is behind a paywall.

Fast hydrogen separation with graphene-wrapped zeolite membranes for clean energy

A May 18, 2022 news item on phys.org highlights the problem with using hydrogen as an energy source,

The effects of global warming are becoming more serious, and there is a strong demand for technological advances to reduce carbon dioxide emissions. Hydrogen is an ideal clean energy which produces water when burned. To promote the use of hydrogen energy, it is essential to develop safe, energy-saving technologies for hydrogen production and storage. Currently, hydrogen is made from natural gas, so it is not appropriate for decarbonization. Using a lot of energy to separate hydrogen would not make it qualify as clean energy.

Polymer separation membranes have the great advantage of enlarging the separation membrane and increasing the separation coefficient. However, the speed of permeation through the membrane is extremely low, and high pressure must be applied to increase the permeation speed. Therefore, a large amount of energy is required for separation using a polymer separation membrane. The goal is to create a new kind of separation membrane technology that can achieve separation speeds that are 50 times faster than that of conventional separation membranes.

A May 18, 2022 Shinshu University (Japan) press release on EurekAlert, which originated the news item, describes a proposed solution to the hydrogen problem,

The graphene-wrapped molecular-sieving membrane prepared in this study has a separation factor of 245 and a permeation coefficient of 5.8 x 106 barrers, which is more than 100 times better than that of conventional polymer separation membranes. If the size of the separation membrane is increased in the future, it is very probable that an energy-saving separation process will be established for the separation of important gases such as carbon dioxide and oxygen as well as hydrogen.

As seen in the transmission electron microscope image in Figure 1 [not shown], graphene is wrapped around the MFI-type zeolite crystal, being hydrophobic. The wrapping uses the principles of colloidal science to keep graphene and zeolite crystal planes close to each other due to reduction of the repulsive interaction. About 5 layers of graphene enclose zeolite crystals in this figure. Around the red arrow, there is a narrow interface space where only hydrogen can permeate. Graphene is also present on hydrophobic zeolite, so the structure of the zeolite crystal cannot be seen with this. Since a strong attractive force acts between graphene, the zeolite crystals wrapped with graphene are in close contact with each other by a simple compression treatment and does not let any gas through.

Figure 2 [not shown] shows a model in which zeolite crystals wrapped with graphene are in contact with each other. The surface of the zeolite crystal has grooves derived from the structure, and there is an interfacial channel between zeolite and graphene through which hydrogen molecules can selectively permeate. The model in which the black circles are connected is graphene, and there are nano-windows represented by blanks in some places. Any gas can freely permeate the nanowindows, but the very narrow channels between graphene and zeolite crystal faces allow hydrogen to permeate preferentially. This structure allows efficient separation of hydrogen and methane. On the other hand, the movement of hydrogen is rapid because there are many voids between the graphene-wrapped zeolite particles. For this reason, ultra-high-speed permeation is possible while maintaining the high separation factor of 200 or more.

Figure 3 [not shown] compares the hydrogen separation factor and gas permeation coefficient for methane with the previously reported separation membranes, which is called Robeson plot. Therefore, this separation membrane separates hydrogen at a speed of about 100 times while maintaining a higher separation coefficient than conventional separation membranes. The farther in the direction of the arrow, the better the performance. This newly developed separation membrane has paved the way for energy-saving separation technologies for the first time.

In addition, this separation principle is different from the conventional dissolution mechanism with polymers and the separation mechanism with pore size in zeolite separation membranes, and it depends on the separation target by selecting the surface structure of zeolite or another crystal. High-speed separation for any target gas is possible in principle. For this reason, if the industrial manufacturing method of this separation membrane and the separation membrane becomes scalable, the chemical industry, combustion industry, and other industries can be significantly improved energy consumption, leading to a significant reduction in carbon dioxide emissions. Currently, the group is conducting research toward the establishment of basic technology for rapidly producing a large amount of enriched oxygen from air. The development of enriched oxygen manufacturing technologies will revolutionize the steel and chemical industry and even medicine.

The figures referenced in the press release are best seen in the context of the paper. I can show you part of Figure 1,

Caption: The black circle connection is a one-layer graphene model, and the nano window is shown as blank. Red hydrogen permeates the gap between graphene and the surface of the zeolite crystal. On the other hand, large CH4 molecules are difficult to permeate. Credit: Copyright©2022 The Authors, License 4.0 (CC BY-NC)

For the rest of Figure 1 and more figures, here’s a link to and a citation for the paper,

Ultrapermeable 2D-channeled graphene-wrapped zeolite molecular sieving membranes for hydrogen separation by Radovan Kukobat, Motomu Sakai, Hideki Tanaka, Hayato Otsuka, Fernando Vallejos-Burgos, Christian Lastoskie, Masahiko Matsukata, Yukichi Sasaki, Kaname Yoshida, Takuya Hayashi and Katsumi Kaneko. Science Advances 18 May 2022 Vol 8, Issue 20 DOI: 10.1126/sciadv.abl3521

This paper is open access.

Artificially designed protein nanoparticle TIP60

As is often the case with research from Japan, I find the work interesting and challenging to read about. An October 5, 2021 news item on Nanowerk describes the nature of the research from Japan,

Nanoparticles and nanocages are attractive materials that may be applied in color agents, catalysts, and drug delivery. For real-world use, it is necessary to produce a large number of nanoparticles of uniform size and shape, but thus far, nanoparticle formation methods using metals have been widely researched, and the formation of nanoparticles with a certain shape and size have been realized. However, it is not easy to create a group of uniform nanoparticles with the same structure at the atomic level.

You might find as I did that this image provided by the researchers is quite helpful (Thank you to the person who made this diagram),

Caption: Sixty fusion proteins of a pentameric Sm-like protein (PDB ID: 3BY7) and a dimeric MyoX-coil domain (PDB ID: 2LW9) self-assemble into a protein nanoparticle complex, TIP60 (Truncated Icosahedral Protein composed of 60-mer fusion proteins). Credit: Reproduced from Icosahedral 60-meric porous structure of designed supramolecular protein nanoparticle TIP60, Ryoichi Arai et al., Chem. Commun., 2021, with permission from the Royal Society of Chemistry.

An October 5, 2021 Shinshu University press release on EurekAlert, which originated the news item, provides further detail

A joint research group led by Associate Professor Ryoichi Arai (Institute for Biomedical Sciences and Faculty of Textile Science and Technology, Shinshu University) and Assistant Professor Norifumi Kawakami (Faculty of Science and Technology, Keio University) developed a uniform and useful supramolecular protein nanoparticle symmetrically self-assembled from fusion proteins of a pentameric protein domain and a dimeric protein domain. It is possible to modify the functionality by site-specific mutagenesis or chemical modification. This designed protein nanoparticle with a diameter of about 22 nm was named TIP60 (Truncated Icosahedral Protein composed of 60-mer fusion proteins) because it is formed by self-assembling 60-meric artificial fusion proteins shaped like a soccer ball (N. Kawakami et al., Angew. Chem. Int. Ed. 57, 12400–12404, 2018).

In the present study, the joint research group solved the detailed three-dimensional structure of the TIP60 using single-particle cryo-electron microscopy. A large amount of TIP60 was expressed in E. coli, and a purified sample was observed at the cryo-electron microscope facility operated by Prof. Masahide Kikkawa lab at the University of Tokyo. By performing single-particle analysis based on obtained image data, a three-dimensional map was reconstructed with a resolution of 3.3 Å. It was revealed that TIP60 forms hollow spherical nanoparticles as designed and has an icosahedral 60-meric structure with 20 triangular-like pores with an edge of about 4 nm each. In addition, the group elucidated in detail the characteristic three-dimensional structure, such as the linker connecting the pentamer formation domain and the dimer formation domain composed of an α-helix.

When a small molecule compound is added after chemically modifying only the outer surface of TIP60 with a high molecular compound, the small molecule compound enters the internal cavity and chemically modifies in the inner surface. In other words, it was found that the porous structure of TIP60 acts as a filter by molecular size, and the outer and inner surfaces of TIP60 can be chemically modified with different molecules of different sizes (E. Nasu et al., ACS Appl. Nano Mater. 4, 2434–2439, 2021).

In the future, the group will utilize artificially designed protein nanoparticles by advancing the design and functional modification of site-specific variants based on the three-dimensional structure of TIP60 elucidated in this study. It is expected to lead to the development and applications in the nanobiotechnology and nanomaterial fields, such as use as a nanocapsule for a drug delivery system

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

Icosahedral 60-meric porous structure of designed supramolecular protein nanoparticle TIP60 by Junya Obata, Norifumi Kawakami, Akihisa Tsutsumi, Erika Nasu, Kenji Miyamoto, Masahide Kikkawa and Ryoichi Arai. Chemical Communications (Chem. Commun., 2021,57, 10226-10229) DOI: https://doi.org/10.1039/D1CC03114G First published 04 Sep 2021

This paper is behind a paywall.

Robust reverse osmosis membranes made of carbon nanotubes

Caption: SEM images of MWCNT-PA (Multi-Walled Carbon Nanotube-Polyamide) nanocomposite membranes, for plain PA, and PA with 5, 9.5, 12.5, 15.5, 17 and 20 wt.% of MWCNT, where the typical lobe-like structures appear at the surface. Note the tendency towards a flatter membrane surface as the content of MWCNT increases. Scale bar corresponds to 1.0?μm for all the micrographs. Credit: Copyright 2018, Springer Nature, Licensed under CC BY 4.0

It seems unlikely that the image’s resemblance to a Japanese kimono on display is accidental. Either way, nicely done!

An April 12, 2018 news item on phys.org describes a technique that would allow large-scale water desalination,

A research team of Shinshu University, Japan, has developed robust reverse osmosis membranes that can endure large-scale water desalination. The team published their results in early February [2018] in Scientific Reports.

“Since more than 97 percent of the water in the world is saline water, reverse osmosis desalination plants for producing fresh water are increasingly important for providing a safe and consistent supply,” said Morinobu Endo, Ph.D., corresponding author on the paper. Endo is a distinguished professor of Shinshu University and the Honorary Director of the Institute of Carbon Science and Technology. “Even though reverse osmosis membrane technology has been under development for several decades, new threats like global warming and increasing clean water demand in populated urban centers challenge the conventional water supply systems.”

Reverse osmosis membranes typically consist of thin film composite systems, with an active layer of polymer film that restricts undesired substances, such as salt, from passing through a permeable porous substrate. Such membranes can turn seawater into drinkable water, as well as aid in agricultural and landscape irrigation, but they can be costly to operate and spend a large amount of energy.

To meet the demand of potable water at low cost, Endo says more robust membranes capable of withstanding harsh conditions, while remaining chemically stable to tolerate cleaning treatments, are necessary. The key lays in carbon nanotechnology.

An April 11, 2018 Shinshu University press release, which originated the news item, provides more details about the work,

Endo is a pioneer of carbon nanotubes [sic] synthesis by catalytic chemical vapor deposition. In this research, Endo and his team developed a multi-walled carbon nanotube-polyamide nanocomposite membrane, which is resistant to chlorine–one of the main cause of degradation or failure cases in reverse osmosis membranes. The added carbon nanotubes create a protective effect that stabilized the linked molecules of the polyamide against chlorine.

“Carbon nanotechnology has been expected to bring benefits, and this is one promising example of the contribution of carbon nanotubes to a very critical application: water purification,” Endo said. “Carbon nanotubes and fibers are already superb reinforcements for other applications in materials science and engineering, and this is yet another field where their exceptional properties can be used for improving conventional technologies.”

The researchers are working to stabilize and expand the production and processing of multi-walled carbon nanotube-polyamide nanocomposite membranes.

“We are currently working on scaling up our method of synthesis, which, in principle, is based on the same method used to prepare current polyamide membranes,” Endo said. He also noted that his team is planning a collaboration to produce commercial membranes.

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

Robust water desalination membranes against degradation using high loads of carbon nanotubes by J. Ortiz-Medina, S. Inukai, T. Araki, A. Morelos-Gomez, R. Cruz-Silva, K. Takeuchi, T. Noguchi, T. Kawaguchi, M. Terrones, & M. Endo. Scientific Reports volume 8, Article number: 2748 (2018) doi:10.1038/s41598-018-21192-5 Published online: 09 February 2018

This paper is open access.

Robotics where and how you don’t expect them: a wearable robot and a robot implant for regeneration

Generally I  expect robots to be machines that are external to my body but recently there were two news bits about some different approaches. First, the wearable robot.

A robot that supports your hip

A January 10, 2018 news item on ScienceDaily describes research into muscles that can be worn,

Scientists are one step closer to artificial muscles. Orthotics have come a long way since their initial wood and strap designs, yet innovation lapsed when it came to compensating for muscle power — until now.

A collaborative research team has designed a wearable robot to support a person’s hip joint while walking. The team, led by Minoru Hashimoto, a professor of textile science and technology at Shinshu University in Japan, published the details of their prototype in Smart Materials and Structures, a journal published by the Institute of Physics.

A January 9, 2018 Shinshu University press release on EurekAlert, which originated the news item, provides more detail,

“With a rapidly aging society, an increasing number of elderly people require care after suffering from stroke, and other-age related disabilities. Various technologies, devices, and robots are emerging to aid caretakers,” wrote Hashimoto, noting that several technologies meant to assist a person with walking are often cumbersome to the user. “[In our] current study, [we] sought to develop a lightweight, soft, wearable assist wear for supporting activities of daily life for older people with weakened muscles and those with mobility issues.”

The wearable system consists of plasticized polyvinyl chloride (PVC) gel, mesh electrodes, and applied voltage. The mesh electrodes sandwich the gel, and when voltage is applied, the gel flexes and contracts, like a muscle. It’s a wearable actuator, the mechanism that causes movement.

“We thought that the electrical mechanical properties of the PVC gel could be used for robotic artificial muscles, so we started researching the PVC gel,” said Hashimoto. “The ability to add voltage to PVC gel is especially attractive for high speed movement, and the gel moves with high speed with just a few hundred volts.”

In a preliminary evaluation, a stroke patient with some paralysis on one side of his body walked with and without the wearable system.

“We found that the assist wear enabled natural movement, increasing step length and decreasing muscular activity during straight line walking,” wrote Hashimoto. The researchers also found that adjusting the charge could change the level of assistance the actuator provides.

The robotic system earned first place in demonstrations with their multilayer PVC gel artificial muscle at the, “24th International Symposium on Smart Structures and Materials & Nondestructive Evaluation and Health Monitoring” for SPIE the international society for optics and photonics.

Next, the researchers plan to create a string actuator using the PVC gel, which could potentially lead to the development of fabric capable of providing more manageable external muscular support with ease.

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

PVC gel soft actuator-based wearable assist wear for hip joint support during walking by Yi Li and Minoru Hashimoto. Smart Materials and Structures, Volume 26, Number 12 DOI: 10.1088/1361-665X/aa9315 Published 30 October 2017

© 2017 IOP Publishing Ltd

This paper is behind a paywall and I see it was published in the Fall of 2017. Either they postponed the publicity or this is the second wave. In any event, it was timely as it allowed me to post this along with the robotic research on regeneration.

Robotic implants and tissue regeneration

Boston Children’s Hospital in a January 10, 2018 news release on EurekAlert describes a new (to me) method for tissue regeneration,

An implanted, programmable medical robot can gradually lengthen tubular organs by applying traction forces — stimulating tissue growth in stunted organs without interfering with organ function or causing apparent discomfort, report researchers at Boston Children’s Hospital.

The robotic system, described today in Science Robotics, induced cell proliferation and lengthened part of the esophagus in a large animal by about 75 percent, while the animal remained awake and mobile. The researchers say the system could treat long-gap esophageal atresia, a rare birth defect in which part of the esophagus is missing, and could also be used to lengthen the small intestine in short bowel syndrome.

The most effective current operation for long-gap esophageal atresia, called the Foker process, uses sutures anchored on the patient’s back to gradually pull on the esophagus. To prevent the esophagus from tearing, patients must be paralyzed in a medically induced coma and placed on mechanical ventilation in the intensive care unit for one to four weeks. The long period of immobilization can also cause medical complications such as bone fractures and blood clots.

“This project demonstrates proof-of-concept that miniature robots can induce organ growth inside a living being for repair or replacement, while avoiding the sedation and paralysis currently required for the most difficult cases of esophageal atresia,” says Russell Jennings, MD, surgical director of the Esophageal and Airway Treatment Center at Boston Children’s Hospital, and a co-investigator on the study. “The potential uses of such robots are yet to be fully explored, but they will certainly be applied to many organs in the near future.”

The motorized robotic device is attached only to the esophagus, so would allow a patient to move freely. Covered by a smooth, biocompatible, waterproof “skin,” it includes two attachment rings, placed around the esophagus and sewn into place with sutures. A programmable control unit outside the body applies adjustable traction forces to the rings, slowly and steadily pulling the tissue in the desired direction.

The device was tested in the esophagi of pigs (five received the implant and three served as controls). The distance between the two rings (pulling the esophagus in opposite directions) was increased by small, 2.5-millimeter increments each day for 8 to 9 days. The animals were able to eat normally even with the device applying traction to its esophagus, and showed no sign of discomfort.

On day 10, the segment of esophagus had increased in length by 77 percent on average. Examination of the tissue showed a proliferation of the cells that make up the esophagus. The organ also maintained its normal diameter.

“This shows we didn’t simply stretch the esophagus — it lengthened through cell growth,” says Pierre Dupont, PhD, the study’s senior investigator and Chief of Pediatric Cardiac Bioengineering at Boston Children’s.

The research team is now starting to test the robotic system in a large animal model of short bowel syndrome. While long-gap esophageal atresia is quite rare, the prevalence of short bowel syndrome is much higher. Short bowel can be caused by necrotizing enterocolitis in the newborn, Crohn’s disease in adults, or a serious infection or cancer requiring a large segment of intestine to be removed.

“Short bowel syndrome is a devastating illness requiring patients to be fed intravenously,” says gastroenterologist Peter Ngo, MD, a coauthor on the study. “This, in turn, can lead to liver failure, sometimes requiring a liver or multivisceral (liver-intestine) transplant, outcomes that are both devastating and costly.”

The team hopes to get support to continue its tests of the device in large animal models, and eventually conduct clinical trials. They will also test other features.

“No one knows the best amount of force to apply to an organ to induce growth,” explains Dupont. “Today, in fact, we don’t even know what forces we are applying clinically. It’s all based on surgeon experience. A robotic device can figure out the best forces to apply and then apply those forces precisely.”

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

In vivo tissue regeneration with robotic implants by Dana D. Damian, Karl Price, Slava Arabagi, Ignacio Berra, Zurab Machaidze, Sunil Manjila, Shogo Shimada, Assunta Fabozzo, Gustavo Arnal, David Van Story, Jeffrey D. Goldsmith, Agoston T. Agoston, Chunwoo Kim, Russell W. Jennings, Peter D. Ngo, Michael Manfredi, and Pierre E. Dupont. Science Robotics 10 Jan 2018: Vol. 3, Issue 14, eaaq0018 DOI: 10.1126/scirobotics.aaq0018

This paper is behind a paywall.