Tag Archives: RIKEN

Inspiration from the sea for titanium implants (mussels) and adhesive panels for flexible sensors (octopuses/octopi/octopodes)

I have two sea-inspired news bits both of which concern adhesion.

Mussels and titanium implants

A July 8, 2016 news item on ScienceDaily features some mussel-inspired research from Japan into how to make better titanium implants,

Titanium is used medically in applications such as artificial joints and dental implants. While it is strong and is not harmful to tissues, the metal lacks some of the beneficial biological properties of natural tissues such as bones and natural teeth. Now, based on insights from mussels–which are able to attach themselves very tightly to even metallic surfaces due to special proteins found in their byssal threads–scientists from RIKEN have successfully attached a biologically active molecule to a titanium surface, paving the way for implants that can be more biologically beneficial.

A July 11, 2016 RIKEN press release (also on EurekAlert but dated July 8, 2016), which originated the news item, provides more information,

The work began from earlier discoveries that mussels can attach to smooth surfaces so effectively thanks to a protein, L-DOPA, which is known to be able to bind very strongly to smooth surfaces such as rocks, ceramics, or metals (…). Interestingly, the same protein functions in humans as a precursor to dopamine, and is used as a treatment for Parkinson’s disease.

According to Chen Zhang of the RIKEN Nano Medical Engineering Laboratory, the first author of the paper published in Angewandte Chemie, “We thought it would be interesting to try to use various techniques to attach a biologically active protein—in our case we chose insulin-like growth factor-1, a promoter of cell proliferation—to a titanium surface like those used in implants” (…).

Using a combination of recombinant DNA technology and treatment with tyrosinase, they were able to create a hybrid protein that contained active parts of both the growth factor and L-DOPA. Tests showed that the proteins were able to fold normally, and further experiments in cell cultures demonstrated that the IGF-1 was still functioning normally. Thanks to the incorporation of the L-DOPA, the team was able to confirm that the proteins bound strongly to the titanium surface, and remained attached even when the metal was washed with phosphate-buffered saline, a water-based solution. Zhang says, “This is similar to the powerful properties of mussel adhesive, which can remain fixed to metallic materials even underwater.”

According to Yoshihiro Ito, Team Leader of the Emergent Bioengineering Research Team of the RIKEN Center for Emergent Matter Science, “We are very excited by this finding, because the modification process is a universal one that could be used with other proteins. It could allow us to prepare new cell-growth enhancing materials, with potential applications in cell culture systems and regenerative medicine. And it is particularly interesting that this is an example of biomimetics, where nature can teach us new ways to do things. The mussel has given us insights that could be used to allow us to live healthier lives.”

The work was done by RIKEN researchers in collaboration with Professor Peibiao Zhang of the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, and Professor Yi Wang of the School of Pharmaceutical Sciences, Jilin University. The work was partially supported by the Japan Society for the Promotion of Science KAKENHI (Grant Number 15H01810 and 22220009), CAS-JSPS joint fund (GJHZ1519), and RIKEN MOST joint project.

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

A Bioorthogonal Approach for the Preparation of a Titanium-Binding Insulin-like Growth-Factor-1 Derivative by using Tyrosinase by Chen Zhang, Hideyuki Miyatake, Yu Wang, Takehiko Inaba, Yi Wang, Peibiao Zhang, and Prof. Yoshihiro Ito. Angewandte Chemie International Edition DOI: 10.1002/anie.201603155 Version of Record online: 6 JUL 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Octopuses/octopi/octopodes and adhesive panels

Before launching into the science part of this news bit, here’s some grammar (from the Octopus Wikipedia entry; Note: Links have been removed),

The standard pluralized form of “octopus” in the English language is “octopuses” /ˈɒktəpʊsɪz/,[10] although the Ancient Greek plural “octopodes” /ɒkˈtɒpədiːz/, has also been used historically.[9] The alternative plural “octopi” — which misguidedly assumes it is a Latin “-us”-word — is considered grammatically incorrect.[11][12][13][14] It is nevertheless used enough to make it notable, and was formally acknowledged by the descriptivist Merriam-Webster 11th Collegiate Dictionary and Webster’s New World College Dictionary. The Oxford English Dictionary (2008 Draft Revision)[15] lists “octopuses”, “octopi”, and “octopodes”, in that order, labelling “octopodes” as rare and noting that “octopi” derives from the apprehension that octōpus comes from Latin.[16] In contrast, New Oxford American Dictionary (3rd Edition 2010) lists “octopuses” as the only acceptable pluralization, with a usage note indicating “octopodes” as being still occasionally used but “octopi” as being incorrect.[17]

Now the news. A July 12, 2016 news item on Nanowerk highlights some research into adhesives and octopuses,

With increased study of bio-adhesives, a significant effort has been made in search for novel adhesives that will combine reversibility, repeated usage, stronger bonds and faster bonding time, non-toxic, and more importantly be effective in wet and other extreme conditions.

A team of Korean scientists-made up of scientists from Korea Institute of Science and Technology (KIST) and UNIST has recently found a way to make building flexible pressure sensors easier–by mimicking the suction cups on octopus’s tentacles.

A July 5, 2016 UNIST (Ulsan National Institute of Science and Technology) press release, which originated the news item, provides more information,

According to the research team, “Although flexible pressure sensors might give future prosthetics and robots a better sense of touch, building them requires a lot of laborious transferring of nano- and microribbons of inorganic semiconductor materials onto polymer sheets.”

In search of an easier way to process this transfer printing, Prof. Hyunhyub Ko (School of Energy and Chemical Engineering, UNIST) and his colleagues turned to the octopus suction cups for inspiration.

An octopus uses its tentacles to move to a new location and uses suction cups underneath each tentacle to grab onto something. Each suction cup contains a cavity whose pressure is controlled by surrounding muscles. These can be made thinner or thicker on demand, increasing or decreasing air pressure inside the cup, allowing for sucking and releasing as desired.

By mimicking muscle actuation to control cavity-pressure-induced adhesion of octopus suckers, Prof. Ko and his team engineered octopus-inspired smart adhesive pads. They used the rubbery material polydimethylsiloxane (PDMS) to create an array of microscale suckers, which included pores that are coated with a thermally responsive polymer to create sucker-like walls.

The team discovered that the best way to replicate organic nature of muscle contractions would be through applied heat. Indeed, at room temperature, the walls of each pit sit in an ‘open’ state, but when the mat is heated to 32°C, the walls contract, creating suction, therby allowing the entire mate to adhere to a material (mimicking the suction function of an octopus). The adhesive strength also spiked from .32 kilopascals to 94 kilopascals at high temperature.

The team reports that the mat worked as envisioned—they made some indium gallium arsenide transistors that sat on a flexible substrate and also used it to move some nanomaterials to a different type of flexible material.

Prof. Ko and his team expect that their smart adhesive pads can be used as the substrate for wearable health sensors, such as Band-Aids or sensors that stick to the skin at normal body temperatures but fall off when rinsed under cold water.

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

Octopus-Inspired Smart Adhesive Pads for Transfer Printing of Semiconducting Nanomembranes by Hochan Lee, Doo-Seung Um, Youngsu Lee, Seongdong Lim, Hyung-jun Kim,  and Hyunhyub Ko. Advanced Materials DOI: 10.1002/adma.201601407 Version of Record online: 20 JUN 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Growing complex skin tissue—complete with hair follicles and sebaceous glands

A laboratory in Japan has managed to grow complex skin tissue according to an April 2, 2016 RIKEN (Japan) press release (also on EurekAlert but dated April 1, 2016),

Using reprogrammed iPS cells, scientists from the RIKEN Center for Developmental Biology (CDB) in Japan have, along with collaborators from Tokyo University of Science and other Japanese institutions, successfully grown complex skin tissue–complete with hair follicles and sebaceous glands–in the laboratory. They were then able to implant these three-dimensional tissues into living mice, and the tissues formed proper connections with other organ systems such as nerves and muscle fibers. This work opens a path to creating functional skin transplants for burn and other patients who require new skin.

Research into bioengineered tissues has led to important achievements in recent years–with a number of different tissue types being created–but there are still obstacles to be overcome. In the area of skin tissue, epithelial cells have been successfully grown into implantable sheets, but they did not have the proper appendages–the oil-secreting and sweat glands–that would allow them to function as normal tissue.

To perform the work, published in Science Advances, the researchers took cells from mouse gums and used chemicals to transform them into stem cell-like iPS cells. In culture, the cells properly developed into what is called an embryoid body (EB)?a three-dimensional clump of cells that partially resembles the developing embryo in an actual body. The researchers created EBs from iPS cells using Wnt10b signaling and then implanted multiple EBs into immune-deficient mice, where they gradually changed into differentiated tissue, following the pattern of an actual embryo. Once the tissue had differentiated, the scientists transplanted them out of those mice and into the skin tissue of other mice, where the tissues developed normally as integumentary tissue?the tissue between the outer and inner skin that is responsible for much of the function of the skin in terms of hair shaft eruption and fat excretion. Critically, they also found that the implanted tissues made normal connections with the surrounding nerve and muscle tissues, allowing it to function normally.

One important key to the development was that treatment with Wnt10b, a signaling molecule, resulted in a larger number of hair follicles, making the bioengineered tissue closer to natural tissue.

According to Takashi Tsuji of the RIKEN Center for Developmental Biology, who led the study, “Up until now, artificial skin development has been hampered by the fact that the skin lacked the important organs, such as hair follicles and exocrine glands, which allow the skin to play its important role in regulation. With this new technique, we have successfully grown skin that replicates the function of normal tissue. We are coming ever closer to the dream of being able to recreate actual organs in the lab for transplantation, and also believe that tissue grown through this method could be used as an alternative to animal testing of chemicals.”

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

Bioengineering a 3D integumentary organ system from iPS cells using an in vivo transplantation model by Ryoji Takagi, Junko Ishimaru, Ayaka Sugawara, Koh-ei Toyoshima, Kentaro Ishida, Miho Ogawa, Kei Sakakibara, Kyosuke Asakawa, Akitoshi Kashiwakura, Masamitsu Oshima, Ryohei Minamide, Akio Sato, Toshihiro Yoshitake, Akira Takeda, Hiroshi Egusa, and Takashi Tsuji. Science Advances  01 Apr 2016: Vol. 2, no. 4, e1500887 DOI: 10.1126/sciadv.1500887

This appears to be an open access paper.

Spins in artificial atoms same as spin in natural atoms

I wonder what impact this research on the spin in artificial and natural atoms will have on how we view the word ‘artificial’. (If artificial molecules/atoms are indistinguishable from natural ones, what does it mean to be artificial?)

An Aug. 7, 2015 news item on Nanowerk describes the finding about spin,

By extending the study of coupled quantum dots to five-electron systems, RIKEN [Japan] researchers have confirmed that the spin-based electron-filling rules for natural atoms apply to artificial molecules …

Systems consisting of electrons and semiconductor quantum dots—nanostructures that exhibit quantum properties—are highly intriguing artificial structures that in many ways mimic naturally occurring atoms. For example, electrons occupy the energy levels of quantum dots according to the same rules that determine how electrons fill atomic shells. Such systems are of both fundamental interest, for investigating phenomena related to nuclear spin, and applied interest, for manipulating spin in future quantum computers.

The Pauli exclusion principle, which prohibits any two electrons in an atom from having identical sets of quantum numbers, gives rise to a phenomenon known as the Pauli spin blockade in quantum-dot systems. This effect prevents electrons from following certain energetically favorable paths through a quantum-dot system since two electrons with the same spin cannot occupy the same energy level.
The Pauli spin blockade has been well studied in artificial molecules consisting of two quantum dots and two electrons. Shinichi Amaha and Seigo Tarucha from RIKEN’s Center for Emergent Matter Science, in collaboration with researchers in Japan and Canada, have extended the study of spin blockade to multilevel quantum-dot systems that have more than two electrons. This requires accessing high-spin states, which is difficult to achieve in practice.

TG Techno’s Aug. 7, 2015 posting of the identical news item fills in more details,

Using a two-quantum-dot system with three effective levels, the researchers have achieved spin blockade by exploiting Hund’s first rule, which dictates that electrons in an atom will first fill unoccupied orbitals of a subshell with greater total spin state. They used this principle to prepare the high-spin states needed for spin blockade …

The team discovered that the current of the device varied unexpectedly with the applied magnetic field. In most devices with spin effects, the current lags behind changes to the magnetic field, a phenomenon known as hysteresis. The researchers found that the hysteresis of their system follows the expected spin states based on a consideration of Hund’s rule and that in certain magnetic field regions two hysteresis effects cancelled each other out—clear evidence that competing ‘up’ and ‘down’ nuclear spin pumping processes influence the current.

These findings are expected to open the way to use arrays of such quantum dots as simulators for spin filling in real molecules. “Using an array of quantum dots as artificial atoms could assist investigations of novel spin-related phenomena in real molecules,” says Amaha.

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

Vanishing current hysteresis under competing nuclear spin pumping processes in a quadruplet spin-blockaded double quantum dot by  S. Amaha, T. Hatano, S. Tarucha, J. A. Gupta, and D. G. Austing. Appl. Phys. Lett. 106, 172401 (2015); http://dx.doi.org/10.1063/1.4919101

This paper is behind a paywall.

Canadian and Japanese researchers create new technique for using iron nanoparticles in greener hydrogenation process

McGill University’s Audrey Moores and her team’s latest green chemistry work with researchers at RIKEN (The Institute of Physical and Chemical Research, Wako, Japan) and the Institute for Molecular Science (Okazaki, Japan) is featured in a June 27, 2013 news item on Nanowerk,

Researchers from McGill University, RIKEN (The Institute of Physical and Chemical Research, Wako, Japan) and the Institute for Molecular Science (Okazaki, Japan) have discovered a way to make the widely used chemical process of hydrogenation more environmentally friendly – and less expensive.

Hydrogenation is a chemical process used in a wide range of industrial applications, from food products, such as margarine, to petrochemicals and pharmaceuticals. The process typically involves the use of heavy metals, such as palladium or platinum, to catalyze the chemical reaction. While these metals are very efficient catalysts, they are also non-renewable, costly, and subject to sharp price fluctuations on international markets.

Because these metals are also toxic, even in small quantities, they also raise environmental and safety concerns. Pharmaceutical companies, for example, must use expensive purification methods to limit residual levels of these elements in pharmaceutical products. Iron, by contrast, is both naturally abundant and far less toxic than heavy metals.

Previous work by other researchers has shown that iron nanoparticles — tiny pieces of metallic iron — can be used to activate the hydrogenation reaction. Iron, however, has a well-known drawback: it rusts in the presence of oxygen or water. When rusted, iron nanoparticles stop acting as hydrogenation catalysts. This problem, which occurs with so much as trace quantities of water, has prevented iron nanoparticles from being used in industry.

The June 27, 2013 McGill University news release on EurekAlert, which originated the news item, provides details about the new technique,

The key to this new method is to produce the particles directly inside a polymer matrix, composed of amphiphilic polymers based on polystyrene and polyethylene glycol. The polymer acts as a wrapping film that protects the iron surface from rusting in the presence of water, while allowing the reactants to reach the water and react.

This innovation enabled the researchers to use iron nanoparticles as catalyst in a flow system, raising the possibility that iron could be used to replace platinum-series metals for hydrogenation under industrial conditions.

“Our research is now focused on achieving a better understanding of how the polymers are protecting the surface of the iron from water, while at the same time allowing the iron to interact with the substrate,” says Audrey Moores, an assistant professor of chemistry at McGill and co-corresponding author of the paper.

“The approach we have developed through this collaboration could lead to more sustainable industrial processes,” says Prof. Uozumi [Prof. Yasuhiro Uozumi of Riken]. “This technique provides a system in which the reaction can happen over and over with the same small amount of a catalytic material, and it enables it to take place in almost pure water — the green solvent par excellence.”

I last wrote about greener chemistry and iron nanoparticles in a March 28, 2012 posting concerning some work at the University of Toronto while the last time McGill, green chemistry, and Audrey Moores were mentioned here was in a Jan. 10, 2011 posting concerning ‘nanomagnetics.

For those who are interested in this latest work from McGill, here’s a link to and a citation for the published paper,

Highly efficient iron(0) nanoparticle-catalyzed hydrogenation in water in flow by Reuben Hudson, Go Hamasaka, Takao Osako, Yoichi M. A. Yamada, Chao-Jun Li, Yasuhiro Uozumi, and Audrey Moores.
Green Chem., 2013, Advance Article DOI: 10.1039/C3GC40789F

First published online 27 Jun 2013

This paper is behind a paywall.

Watching zinc, iron, and copper molecules real-time as they interact with biomolecules

Eventually they’re hoping this work will lead to insights about diabetes and cancer. In the meantime, researchers at RIKEN Center for Life Science Technologies (Japan) have developed a new imaging technique that allows them to observe metal molecules interacting with biomolecules in real-time. From the May 2, 2013 news release on EurekAlert,

Metal elements and molecules interact in the body but visualizing them together has always been a challenge. Researchers from the RIKEN Center for Life Science Technologies in Japan have developed a new molecular imaging technology that enables them to visualize bio-metals and bio-molecules simultaneously in a live mouse. This new technology will enable researchers to study the complex interactions between metal elements and molecules in living organisms.

It’s well known we need zinc, iron, and copper in our bodies for proper functioning. Until now, no one has been able to observe the interaction in real-time, from the RIKEN May 2, 2013 press release (which originated the EurekAlert news release),

In the study, the researchers were able to visualise two radioactive agents injected in a tumor-bearing mouse, as well as an anti-tumor antibody labelled with a PET molecular probe agent, simultaneously in the live mouse.

This new revolutionary technology is expected to offer new insights into the relationships between bio-metal elements and associated bio-molecules, and the roles they play in diseases such as diabetes and cancer.

The researchers had to create a camera capable of visualizing the interactions (from the RIKEN press release),

Dr. Shuichi Enomoto, Dr. Shinji Motomura and colleagues, from the RIKEN Center for Life Science Technologies have developed a gamma-ray imaging camera enabling them to detect the gamma-rays emitted by multiple bio-metal elements in the body and study their behavior.

Their second prototype of the system, called GREI–II and presented today in the Journal of Analytical Atomic Spectrometry, enables them to visualize multiple bio-metal elements more than 10 times faster than before, and to do so simultaneously with positron emission tomography (PET).

You can find the research study here.

For those unfamiliar with RIKEN, here’s more from their About RIKEN page,

RIKEN is Japan’s largest comprehensive research institution renowned for high-quality research in a diverse range of scientific disciplines. Founded in 1917 as a private research foundation in Tokyo, RIKEN has grown rapidly in size and scope, today encompassing a network of world-class research centers and institutes across Japan.

Asia’s research effort in nano-, bio-, and information technology integrated in Asian Research Network

The Feb. 29, 2012 news item by Cameron Chai on Azonano spells it out,

An Asian Research Network (ARN) has been formed by the Hanyang University of Korea and RIKEN of Japan in collaboration with other institutes and universities in Asia. This network has been launched to reinforce a strong education and research collaboration throughout Asia.

The Asian Research Network website is here. You will need to use your scroll bars as it appears to be partially constructed (or maybe my system is so creaky that I just can’t see everything on the page). Towards the bottom (right side) of the home page,there are a couple of red buttons for PDFs of the ARN Pamphlet and Research Articles.

From page 2 of the ARN pamphlet, here’s a listing of the member organizations,

KOREA

Hanyang University
Samsung Electronics
Electronics and Telecommunication Research Institute
Seoul National University
Institute of Pasteur Korea
Korea Research Institute of Chemical Technology
Korea Advanced Nano Fab Center

JAPAN

RIKEN

INDIA

National Chemical Laboratory
Shivaji University
Indian Institutes of Science Education and Research
Pune University
Indian Institute of Technology-Madras (In Progress)
Indian Institute of Science (In Progress)

USA

University of Texas at Dallas
UCLA (In Progress)
f d i i ( )

CHINA

National Center for Nanoscience and Technology
Peking University

SINGAPORE

National University of Singapore
Nanyang Technological University (In Progress)
Stanford University In Progress)
University of Maryland (In Progress)

ISRAEL

Weizmann Institute of Science (In Progress)
Hebrew University Jerusalem

THAILAND

National Science and Technology Development Agency (In Progress)

I was a little surprised to see Israel on the list and on an even more insular note, why no Canada?

Getting back to the ARN, here are their aims, from page 2 of the ARN pamphlet,

We are committed to fostering talented human resources, creating a research network in which researchers in the region share their knowledge and experiences, and establishing a future-oriented partnership to globalize our research capabilities. To this end, we will achieve excellence in all aspects of education, research, and development in the area of fusion research between BT [biotechnology] and IT [information technology] based on NT [nanotechnology] in general. We will make a substantial contribution to the betterment of the global community as well as the Asian society.

I look forward to hearing more from them in the future.

Canada-Japan Nanotechnology Workshop at the University of Waterloo

Today (Nov. 21, 2011) and tomorrow (Nov. 22), the Waterloo Institute for Nanotechnology (WIN) at the University of Waterloo is hosting a nanotechnology workshop celebrating the 25th anniversary of the Canada-Japan Agreement on Cooperation in Science and Technology. The Honourable Gary Goodyear Minister of State (Science and Technology) gave the opening remarks (from the Nov. 21, 2011 news release on the Industry Canada website),

“There are tremendous opportunities for international researchers and businesses to come to Canada and invest in research and development,” said Minister of State Goodyear. “This conference allows us to showcase opportunities in nanotechnology and promote stronger linkages with Canadian researchers and innovators. The relationship we are building will benefit the Canadian and Japanese economies.”

The conference drew a number of high-profile delegates, including His Excellency Kaoru Ishikawa, Ambassador of Japan to Canada and Mr. Yasuyoshi Kakita, Director of the Generic Research and Research Platform Division of Japan’s Ministry of Education, Culture, Sports, Science and Technology.

WIN’s workshop webpage offers more details about the Canada-Japan relationship and our mutual interest in nanotechnology,

Nanotechnology is identified in both countries as a priority area by the Expert Advisory Group (EAG) on Canada-Japan S&T Cooperation. Four major nanotechnology collaborations were recently identified by the Embassies of Japan and Canada for their on-going execution of annual workshops, proven mobility and exchange programs, research funding and number of projects initiated. These are: (in order of MOU signing).

– National Institute for Nanotechnology (NINT) & National Institute of Advanced Industrial Science and Technology (AIST) – 2006
– NanoQuebec & Nagano Techno Foundation – 2009
– Waterloo Institute for Nanotechnology (WIN) & National Institute for Materials Science (NIMS) – 2010
– McGill University & RIKEN – 2010

The Canada-Japan nanotechnology workshop is designed to bring Canadian and Japanese stakeholders together to highlight their success at a national level and for individual researcher teams to advance their collaborative projects. Scientists including Canadian Research Chairs in the field of nanotechnology, government representatives and administrators from leading universities and nanotechnology organizations will be on hand to discuss the future of nanotechnology and recommend paths ahead.

By coming together we will help define a nanotechnology road map for Canada and Japan cooperation that will identify future areas for research funding, commercialization and trade for our respective Governments and Embassies. [emphasis mine]

I’m not sure how they’re going to be able to define a nanotechnology road map for cooperation with Japan when there isn’t any kind of nanotechnology roadmap for Canada. You can check that out for yourself here.

I hope there will be more news from the workshop as it progresses.