Monthly Archives: August 2019

Nanowires with fast infrared light (IR) response and more

An April 10, 2019 news item on Nanowerk points the way to improved high-speed communication with nanowires (Note: A link has been removed),

Chinese scientists have synthesized new nanowires with high carrier mobility and fast infrared light (IR) response, which could help in high-speed communication. Their findings were published in Nature Communications (“Ultra-fast photodetectors based on high-mobility indium gallium antimonide nanowires”).

Below, you will find an image illustrating the researchers’ work ,

Caption: The growth mechanism and fast 1550 nm IR detection of the single-crystalline In0.28Ga0.72Sb ternary nanowires Credit: HAN Ning

An April 10, 2019 Chinese Academy of Sciences news release (also on EurekAlert), which originated the news item, provides more detail,

Nowadays, effective optical communications use 1550 nm IR, which is received and converted into an electrical signal for computer processing. Fast light-to-electrical conversion is thus essential for high-speed communications.

According to quantum theory, 1550 nm IR has energy of ~ 0.8 eV, and can only be detected by semiconductors with bandgaps lower than 0.8 eV, such as germanium (0.66 eV) and III-V compound materials such as InxGa1-xAs (0.35-1.42 eV) and InxGa1-xSb (0.17-0.73 eV). However, those materials usually have huge crystal defects, which cause substantial degradation of photoresponse performance.

Scientists from the Institute of Process Engineering (IPE) of the Chinese Academy of Sciences, City University of Hong Kong (CityU) and their collaborators synthesized highly crystalline ternary In0.28Ga0.72Sb nanowires to demonstrate high carrier mobility and fast IR response.

In this study, the In0.28Ga0.72Sb nanowires (bandgap 0.69 eV) showed a high responsivity of 6000 A/W to IR with high response and decay times of 0.038ms and 0.053ms, respectively, which are some of the best times so far. The fast IR response speed can be attributed to the minimized crystal defects, as also illustrated by a high hole mobility of up to 200 cm2/Vs, according to Prof. Johnny C. Ho from CityU.

The minimized crystal defect is achieved by a “catalyst epitaxy technology” first established by Ho’s group. Briefly, the III-V compound nanowires are catalytically grown by a metal catalyst such as gold, nickel, etc.

“These catalyst nanoparticles play a key role in nanowire growth as the nanowires are synthesized layer by layer with the atoms well aligned with those in the catalyst,” said HAN Ning, a professor at IPE and senior author of the paper.

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

Ultra-fast photodetectors based on high-mobility indium gallium antimonide nanowires by Dapan Li, Changyong Lan, Arumugam Manikandan, SenPo Yip, Ziyao Zhou, Xiaoguang Liang, Lei Shu, Yu-Lun Chueh, Ning Han & Johnny C. Ho. Nature Communicationsvolume 10, Article number: 1664 (2019) DOI: https://doi.org/10.1038/s41467-019-09606-y Published 10 April 2019

This paper is open access.

Biohybrid cyborgs

Cyborgs are usually thought of as people who’ve been enhanced with some sort of technology, In contemporary real life that technology might be a pacemaker or hip replacement but in science fiction it’s technology such as artificial retinas (for example) that expands the range of visible light for an enhanced human.

Rarely does the topic of a microscopic life form come up in discussion about cyborgs and yet, that’s exactly what an April 3, 2019 Nanowerk spotlight article by Michael Berger describes in relationship to its use in water remediation efforts (Note: links have been removed),

Researchers often use living systems as inspiration for the design and engineering of micro- and nanoscale propulsion systems, actuators, sensors, and robots. …

“Although microrobots have recently proved successful for remediating decontaminated water at the laboratory scale, the major challenge in the field is to scale up these applications to actual environmental settings,” Professor Joseph Wang, Chair of Nanoengineering and Director, Center of Wearable Sensors at the University California San Diego, tells Nanowerk. “In order to do this, we need to overcome the toxicity of their chemical fuels, the short time span of biocompatible magnesium-based micromotors and the small domain operation of externally actuated microrobots.”

In their recent work on self-propelled biohybrid microrobots, Wang and his team were inspired by recent developments of biohybrid cyborgs that integrate self-propelling bacteria with functionalized synthetic nanostructures to transport materials.

“These tiny cyborgs are incredibly efficient for transport materials, but the limitation that we observed is that they do not provide large-scale fluid mixing,” notes Wang. ” We wanted to combine the best properties of both worlds. So, we searched for the best candidate to create a more robust biohybrid for mixing and we decided on using rotifers (Brachionus) as the engine of the cyborg.”

These marine microorganisms, which measure between 100 and 300 micrometers, are amazing creatures as they already possess sensing ability, energetic autonomy, and provide large-scale fluid mixing capability. They are also are very resilient and can survive in very harsh environments and even are one of the few organisms that have survived via asexual reproduction.

“Taking inspiration from the science fiction concept of a cybernetic organism, or cyborg – where an organism has enhanced abilities due to the integration of some artificial component – we developed a self-propelled biohybrid microrobot, that we named rotibot, employing rotifers as their engine,” says Fernando Soto, first author of a paper on this work (Advanced Functional Materials, “Rotibot: Use of Rotifers as Self-Propelling Biohybrid Microcleaners”).

This is the first demonstration of a biohybrid cyborg used for the removal and degradation of pollutants from solution. The technical breakthrough that allowed the team to achieve this task is based on a novel fabrication mechanism based on the selective accumulation of functionalized microbeads in the microorganism’s mouth: The rotifer serves not only as a transport vessel for active material or cargo but also acting as a powerful biological pump, as it creates fluid flows directed towards its mouth

Nanowerk has made this video demonstrating a rotifer available along with a description,

“The rotibot is a rotifer (a marine microorganism) that has plastic microbeads attached to the mouth, which are functionalized with pollutant-degrading enzymes. This video illustrates a free swimming rotibot mixing tracer particles in solution. “

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

Rotibot: Use of Rotifers as Self‐Propelling Biohybrid Microcleaners by Fernando Soto, Miguel Angel Lopez‐Ramirez, Itthipon Jeerapan, Berta Esteban‐Fernandez de Avila, Rupesh, Kumar Mishra, Xiaolong Lu, Ingrid Chai, Chuanrui Chen, Daniel Kupor. Advanced Functional Materials DOI: https://doi.org/10.1002/adfm.201900658 First published: 28 March 2019

This paper is behind a paywall.

Berger’s April 3, 2019 Nanowerk spotlight article includes some useful images if you are interested in figuring out how these rotibots function.

Cyborg organoids?

Every time I think I’ve become inured to the idea of a fuzzy boundary between life and nonlife something new crosses my path such as integrating nanoelectronics with cells for cyborg organoids. An August 9, 2019 news item on ScienceDaily makes the announcement,

What happens in the early days of organ development? How do a small group of cells organize to become a heart, a brain, or a kidney? This critical period of development has long remained the black box of developmental biology, in part because no sensor was small or flexible enough to observe this process without damaging the cells.

Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have grown simplified organs known as organoids with fully integrated sensors. These so-called cyborg organoids offer a rare glimpse into the early stages of organ development.

An August 8, 2019 Harvard John A. Paulson School of Engineering and Applied Sciences news release (also on EurekAlert but published August 9, 2019) by Leah Burrows, which originated the news item, expands on the theme,

“I was so inspired by the natural organ development process in high school, in which 3D organs start from few cells in 2D structures. I think if we can develop nanoelectronics that are so flexible, stretchable, and soft that they can grow together with developing tissue through their natural development process, the embedded sensors can measure the entire activity of this developmental process,” said Jia Liu, Assistant Professor of Bioengineering at SEAS and senior author of the study. “The end result is a piece of tissue with a nanoscale device completely distributed and integrated across the entire three-dimensional volume of the tissue.”

This type of device emerges from the work that Liu began as a graduate student in the lab of Charles M. Lieber, the Joshua and Beth Friedman University Professor. In Lieber’s lab, Liu once developed flexible, mesh-like nanoelectronics that could be injected in specific regions of tissue.

Building on that design, Liu and his team increased the stretchability of the nanoelectronics by changing the shape of the mesh from straight lines to serpentine structures (similar structures are used in wearable electronics). Then, the team transferred the mesh nanoelectronics onto a 2D sheet of stem cells, where the cells covered and interwove with the nanoelectronics via cell-cell attraction forces. As the stem cells began to morph into a 3D structure, the nanoelectronics seamlessly reconfigured themselves along with the cells, resulting in fully-grown 3D organoids with embedded sensors.

The stem cells were then differentiated into cardiomyocytes — heart cells — and the researchers were able to monitor and record the electrophysiological activity for 90 days.

“This method allows us to continuously monitor the developmental process and understand how the dynamics of individual cells start to interact and synchronize during the entire developmental process,” said Liu. “It could be used to turn any organoid into cyborg organoids, including brain and pancreas organoids.”

In addition to helping answer fundamental questions about biology, cyborg organoids could be used to test and monitor patient-specific drug treatments and potentially used for transplantations.

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

Cyborg Organoids: Implantation of Nanoelectronics via Organogenesis for Tissue-Wide Electrophysiology by Qiang Li, Kewang Nan, Paul Le Floch, Zuwan Lin, Hao Sheng, Thomas S. Blum, Jia Liu. Nano Lett.20191985781-5789 DOI: https://doi.org/10.1021/acs.nanolett.9b02512 Publication Date:July 26, 2019 Copyright © 2019 American Chemical Society

This paper is behind a paywall.

Cyborgs based on melanin circuits

Pigments for biocompatible electronics? According to a March 26, 2019 news item on Nanowerk this is a distinct possibility (Note: A link has been removed),

The dark brown melanin pigment, eumelanin, colors hair and eyes, and protects our skin from sun damage. It has also long been known to conduct electricity, but too little for any useful application – until now.

In a landmark study published in Frontiers in Chemistry (“Evidence of Unprecedented High Electronic Conductivity in Mammalian Pigment Based Eumelanin Thin Films After Thermal Annealing in Vacuum”), Italian researchers subtly modified the structure of eumelanin by heating it in a vacuum.

“Our process produced a billion-fold increase in the electrical conductivity of eumelanin,” say study senior authors Dr. Alessandro Pezzella of University of Naples Federico II and Dr. Paolo Tassini of Italian National Agency for New Technologies, Energy and Sustainable Economic Development. “This makes possible the long-anticipated design of melanin-based electronics, which can be used for implanted devices due to the pigment’s biocompatibility.”

This is a rather dreamy image to illustrate the point,

Despite extensive research on the structure of melanin, nobody has yet managed to harness its potential in implantable electronics. Image: Shutterstock. [downloaded from https://blog.frontiersin.org/2019/03/26/will-cyborgs-circuits-be-made-from-melanin/]

A March 26, 2019 Frontiers in Chemistry (journal) press release (also on EurekAlert), which originated the news item, expands on the theme,

A young Pezzella had not even begun school when scientists first discovered that a type of melanin can conduct electricity. Excitement quickly rose around the discovery because eumelanin – the dark brown pigment found in hair, skin and eyes – is fully biocompatible.

“Melanins occur naturally in virtually all forms of life. They are non-toxic and do not elicit an immune reaction,” explains Pezzella. “Out in the environment, they are also completely biodegradable.”

Decades later, and despite extensive research on the structure of melanin, nobody has managed to harness its potential in implantable electronics.

“To date, conductivity of synthetic as well as natural eumelanin has been far too low for valuable applications,” he adds.

Some researchers tried to increase the conductivity of eumelanin by combining it with metals, or super-heating it into a graphene-like material – but what they were left with was not truly the biocompatible conducting material promised.

Determined to find the real deal, the Neapolitan group considered the structure of eumelanin.

“All of the chemical and physical analyses of eumelanin paint the same picture – of electron-sharing molecular sheets, stacked messily together. The answer seemed obvious: neaten the stacks and align the sheets, so they can all share electrons – then the electricity will flow.”

This process, called annealing, is used already to increase electrical conductivity and other properties in materials such as metals.

For the first time, the researchers put films of synthetic eumelanin through an annealing process under high vacuum to neaten them up – a little like hair straightening, but with only the pigment.

“We heated these eumelanin films – no thicker than a bacterium – under vacuum conditions, from 30 min up to 6 hours,” describes Tassini. “We call the resulting material High Vacuum Annealed Eumelanin, HVAE.”

The annealing worked wonders for eumelanin: the films slimmed down by more than half, and picked up quite a tan.

“The HVAE films were now dark brown and about as thick as a virus,” Tassini reports.

Crucially, the films had not simply been burnt to a crisp.

“All our various analyses agree that these changes reflect reorganization of eumelanin molecules from a random orientation to a uniform, electron-sharing stack. The annealing temperatures were too low to break up the eumelanin, and we detected no combustion to elemental carbon.”

Having achieved the intended structural changes to eumelanin, the researchers proved their hypothesis in spectacular fashion.

“The conductivity of the films increased billion-fold to an unprecedented value of over 300 S/cm, after annealing at 600°C for 2 hours,” Pezzella confirms.

Although well short of most metal conductors – copper has a conductivity of around 6 x 107 S/cm – this finding launches eumelanin well into a useful range for bioelectronics.

What’s more, the conductivity of HVAE was tunable according to the annealing conditions.

“The conductivity of the films increased with increasing temperature, from 1000-fold at 200°C. This opens the possibility of tailoring eumelanin for a wide range of applications in organic electronics and bioelectronics. It also strongly supports the conclusion from structural analysis that annealing reorganized the films, rather than burning them.”

There is one potential dampener: immersion of the films in water results in a marked decrease in conductivity.

“This contrasts with untreated eumelanin which, albeit in a much lower range, becomes more conductive with hydration (humidity) because it conducts electricity via ions as well as electrons. Further research is needed to fully understand the ionic vs. electronic contributions in eumelanin conductivity, which could be key to how eumelanin is used practically in implantable electronics.” concludes Pezzella.

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

Evidence of Unprecedented High Electronic Conductivity in Mammalian Pigment Based Eumelanin Thin Films After Thermal Annealing in Vacuum by Ludovico Migliaccio, Paola Manini, Davide Altamura, Cinzia Giannini, Paolo Tassini, Maria Grazia Maglione, Carla Minarini, and Alessandro Pezzella. Front. Chem., 26 March 2019 DOI: https://doi.org/10.3389/fchem.2019.00162

This paper is open access.

No mention of climate change or environmental impact? Transforming Canadian science through infrastructure; a report from the Council of Canadian Academies

If there’s a topic that cries out for passion it’s infrastructure. It can be the only thing that will sustain you as the years go by in your quest to improve wonky and sometimes dangerous buildings (e.g. the Science and Technology Museum of Canada prior to i2017; see Ivan Semeniuk’s Nov. 12, 2017 article for the Globe & Mail about the refurbished museum), address poorly designed work environments, and replace inadequate tools and equipment.

Unless you count the report itself , you won’t find any more evidence of passion in the Council of Canadian Academies’ (CCA) report, ‘Building Excellence; The Expert Panel on Leading Practices for Transforming Canadian Science Through Infrastructure’ (webpage). There is a lot of good stuff and I’ll start with that after the description of the panel’s remit. Finally, there’ll be some shortcomings including the failure to make any mention of climate change or environmental impacts. By the way, this posting will not feature an exhaustive analysis.

Rules of the game

For those who don’t know, all of the reports written and published by the CCA are at the request of a government body. From Building Excellence (Note: I have not been able replicate the report formatting),

Public Services and Procurement Canada (the Sponsor) asked the Council of Canadian Academies (CCA) to assess the evidence on leading practices for federal S&T infrastructure investment decisions. Specifically, the Sponsor posed the following questions:

What is known about leading practices for evaluating proposals for science and technology infrastructure investments that is relevant to Canadian federal science for the future?

What processes and advisory structures have been used for reviewing proposals for significant science infrastructure investments, and what is known about their strengths and weaknesses?

What guiding principles and criteria can help assess proposals that support the federal vision for science in Canada, including, for example, interdisciplinarity? [p. 15 PDF; p. 1 print]

Defining infrastructure

In this report they seem to be using the terms scope and definition interchangeably (from Building Excellence),

… In consultation with the Sponsor, the Panel confirmed the scope of the assessment, which included investments in S&T infrastructure that is multi-sectoral, multidisciplinary, and multi-departmental. These investments will be focused on government mission-oriented (or priority-driven) research and development (R&D) and related scientific activities (RSA), such as regulatory science and long-term data collection and monitoring. Out of scope were facilities housing a single department, non-federal science infrastructure, mobile assets (e.g., vessels), global research infrastructure (e.g., CERN), and large infrastructure for basic research (e.g., telescopes). [p. 15 PDF; p. 1 print]

Although the Panel defined infrastructure broadly, the focus of this assessment is primarily on buildings and facilities. However, S&T infrastructure can include a variety of resources, as depicted in Figure 1.1

• equipment, instruments, and tools;
• knowledge-based resources such as libraries, archives, specimen collections, and databases; • cyberinfrastructure, communications, and IT support including hardware, software, services, and personnel;
• animal colonies, cell lines, and plant or bacteria strains;
• technical support staff and services; and
• administrative, management, and governance structures.

(Neal et al., 2008) [p. 16 PDF; p. 2 print]

Unfortunately, I can’t include the infrastructure image referred to as Figure 1.1 but you can find it in the report.

Building Excellence: the good stuff

Gender parity

There were four people on the expert panel; two women and two men. This marks the first time I’ve stumbled across a 50/50 split for any of these expert panels. I realize that ‘standard’ gender categories are seen as reductive and that gender can be fluid, dynamic, and multilayered but, for the moment, I’d like to applaud a tiny step for ‘gender parity’ in the right direction.

The future

It’s very encouraging to see that the authors and other contributors (a workshop was held) are looking to not only fix current problems but anticipate future directions for Canadian government research (from Building Excellence),

Leading practices in decision-making for S&T infrastructure investments take into consideration four principles: scientific excellence, collaboration, feasibility, and broader impacts.

These principles help ensure that S&T infrastructure investments build for a future in which agile, cross-disciplinary, collaborative facilities allow government scientists to engage meaningfully with each other, as well as with collaborators from academia, industry, Indigenous communities, non-governmental organizations, and local organizations, to meet challenges as they arise. Robust evaluations of infrastructure investment proposals also consider the needs of government science, including the urgent need to address existing deficits in infrastructure. [p. 11 PDF; p. IX print]

Also, it’s more than nice to see support staff singled out. Too often there’s a failure to recognize the important role that support staff plays (from Building Excellence),

S&T [science and technology] infrastructure that supports collaboration can amplify science outcomes and lead to solutions for complex challenges.

Collaborative S&T infrastructure proposals highlight the ways that new users can find opportunities for engagement within a facility, and support building relationships by addressing potential barriers to access. Dedicated, professional support staff [emphasis mine] hold the institutional knowledge that facilitates relationship building and enables new collaborations to face future challenges. S&T infrastructure proposals that provide different types of spaces — such as private, formal meeting, semi-open, open, virtual, and overbuilt spaces — support different but equally vital aspects of collaborative work. [p. 11 PDF; p. IX print]

Co-creating sounds promising

In engineering and community organizing there’s top-down and bottom-up engineering/organizing; this is the first I’ve heard of ‘middle-out’ which leads, apparently, to co-creation (from Building Excellence),

A “middle-out” approach to developing proposals facilitates relationship building from the outset of the proposal process and can ensure the success of collaborative S&T infrastructure.

In a middle-out approach, funders request proposals that address specific objectives and manage a process in which the community [emphasis mine] refines proposals collaboratively. This approach allows the S&T community to co-create promising proposals that meet government needs. In contrast, bottom-up approaches (developed solely by the community) might overlook government-mandated activities and top-down approaches (developed solely by funders) might limit collaborative opportunities [p. 12 PDF; p. X print]

So, if the proposal comes from the S&T (science and technology) community it’s a bottom-up process? What about the larger community? I gather we don’t count. (sigh) I did indicate this would be focused on the good. Here goes: it’s good to see that there is a focus on co-creating or, what some might call collaboration, between scientists and government funding agencies.

Good stuff: final thoughts

This is a thoughtful, readable, carefully constructed report.

The weird and the overlooked

I find it weird that there isn’t more information and insight solicited from parts of the world that are not in Europe, or one of the Commonwealth countries, or the US, in addition to the Canadian input. Take a look (from Building Excellence),

There is limited publicly available evidence on infrastructure evaluation processes for intramural government S&T facilities. Therefore, the Panel looked to organizations that evaluate proposals for research infrastructure dedicated to basic discovery-oriented research, including large-scale big science facilities. The review of these organizations was complemented by interviews with individuals familiar with top research infrastructure programs around the world. Specifically, the Panel examined evidence for reviewing research infrastructure proposals in:

• Australia: National Collaborative Research Infrastructure Strategy (NCRIS);
• Canada: Canada Foundation for Innovation (CFI);
• Denmark: Nationalt Udvalg for Forskningsinfrastruktur [National Committee for Research Infrastructure] (NUFI);
• European Union: European Strategy Forum on Research Infrastructures (ESFRI);
• Germany: Bundesministerium für Bildung und Forschung [Federal Ministry of Education and Research] (BMBF);
• United Kingdom: Science and Technology Facilities Council (STFC); and
• United States: Major Research Equipment and Facilities Construction (MREFC). [p. 16 PDF; p. 2 print]

It’s quite possible there was an attempt to reach out beyond the ‘usual suspects’ but it’s not apparent so maybe it’s time they started including a section on attempts made to reach out and broaden the expertise brought to the table/report and perhaps note some of the other exclusions and why they had to be made.

As per the head for this posting, there’s no mention of climate change or environmental impact. Given that this is a report about buildings (for the most part) and presumably the old ones will be retrofitted or there will be new buildings, how is there no mention of the environmental impact of these proposed changes? It just seems odd to me especially since the lead on the expert panel is Wendy Watson-Wright, Chief Executive Officer of the Ocean Frontier Institute. Here’s what’s on the Ocean Frontier Institute‘s home page,

SAFE AND SUSTAINABLE DEVELOPMENT OF THE OCEAN FRONTIER

Safe and sustainable, eh? Where is that in the report?

There’s more. A peer review process, a standard practice, was undertaken for this report. It included Karen Dodds, Former Assistant Deputy Minister, Science and Technology Branch, Environment and Climate Change Canada [emphasis mine].

What happened?

It’s a mystery and not one that is likely to be solved unless … somebody would like to contact me and give me the inside story: nano@frogheart.ca.

One other odd thing, the agency which initiated Building Excellence, Public Services and Procurement Canada (PSPC), was in charge of the Phoenix Pay System, which is widely considered one of the greatest government debacles in Canadian history. You can read this Wikipedia entry for a fairly restrained description.

This connection between PSPC and the Phoenix pay system raises questions, in my mind if no one else’s, as to whether or not the agency has learned any lessons from the experience. A July 31, 2018 news item on the Canadian Broadcasting Corporation (CBC) online news website had this title: Senate committee ‘not confident’ government has learned lessons from Phoenix. So who’s going to be in charge of this infrastructure, what failsafes do they have in place, and will warnings be heeded?

The blogger misses an important piece of information

In 2018, the government announced Canada’s Science Vision in a video of Minister of Science Kirsty Duncan posted on October 10, 2018 and I didn’t catch it.

Try as I might, I cannot find a news release for this announcement but I did find a Canada’s Science Vision website.

I think that if I’m going to point out other people’s shortcomings I have to be willing to admit my own and this was definitely a fail on my part.

Final bit

I’m glad to see that infrastructure for government science is being addressed and, as noted earlier, this is a thoughtful report. Let’s hope that climate change and environmental impact will somehow also be considered in the context of science infrastructure and there will be new points of view (experts and/or agencies not based in the European Union, the United States and/or the United Kingdom) represented in any future reports.

Canadian researchers develop bone implant material from cellulose nanocrystals (CNC) while Russian scientists restore internal structure of bone with polycaprolactone nanofibers

Two research groups are working to the same end where bone marrow is concerned, encourage bone cell growth, but they are using different strategies.

University of British Columbia and McMaster University (Canada)

Caption: Researchers treated nanocrystals derived from plant cellulose so that they can link up and form a strong but lightweight sponge (an aerogel) that can compress or expand as needed to completely fill out a bone cavity. Credit: Clare Kiernan, UBC

The samples look a little like teeth, don’t they?

Before diving into the research news, there’s a terminology issue that should be noted as you’ll see when you read the news/press releases. Nanocrystal cellulose/nanocrystalline cellulose (NCC) is a term coined by Canadian researchers. Since those early day, most researchers, internationally, have adopted the term cellulose nanocrystals (CNC) as the standard term. It fits better with the naming conventions for other nnanocellulose materials such as cellulose nanofibrils, etc. By the way, a Canadian company (CelluForce) that produces CNC retained the term nanocrystalline cellulose (NCC) as a trademark for the product, CelluForce NCC®.

For anyone not familiar with aerogels, what the University of British Columbia (UBC) and McMaster University researchers are developing, are also popularly known known as ‘frozen smoke’ (see the Aerogel Wikipedia entry for more).

A March 19, 2019 news item on ScienceDaily announces the research,

Researchers from the University of British Columbia and McMaster University have developed what could be the bone implant material of the future: an airy, foamlike substance that can be injected into the body and provide scaffolding for the growth of new bone.

It’s made by treating nanocrystals derived from plant cellulose so that they link up and form a strong but lightweight sponge — technically speaking, an aerogel — that can compress or expand as needed to completely fill out a bone cavity.

A March 19, 2019 UBC news release (also on EurekAlert), which originated the news item, describes the research in more detail,

“Most bone graft or implants are made of hard, brittle ceramic that doesn’t always conform to the shape of the hole, and those gaps can lead to poor growth of the bone and implant failure,” said study author Daniel Osorio, a PhD student in chemical engineering at McMaster. “We created this cellulose nanocrystal aerogel as a more effective alternative to these synthetic materials.”

For their research, the team worked with two groups of rats, with the first group receiving the aerogel implants and the second group receiving none. Results showed that the group with implants saw 33 per cent more bone growth at the three-week mark and 50 per cent more bone growth at the 12-week mark, compared to the controls.

“These findings show, for the first time in a lab setting, that a cellulose nanocrystal aerogel can support new bone growth,” said study co-author Emily Cranston, a professor of wood science and chemical and biological engineering who holds the President’s Excellence Chair in Forest Bio-products at UBC. She added that the implant should break down into non-toxic components in the body as the bone starts to heal.

The innovation can potentially fill a niche in the $2-billion bone graft market in North America, said study co-author Kathryn Grandfield, a professor of materials science and engineering, and biomedical engineering at McMaster who supervised the work.

“We can see this aerogel being used for a number of applications including dental implants and spinal and joint replacement surgeries,” said Grandfield. “And it will be economical because the raw material, the nanocellulose, is already being produced in commercial quantities.”

The researchers say it will be some time before the aerogel makes it out of the lab and into the operating room.

“This summer, we will study the mechanisms between the bone and implant that lead to bone growth,” said Grandfield. “We’ll also look at how the implant degrades using advanced microscopes. After that, more biological testing will be required before it is ready for clinical trials.”

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

Cross-linked cellulose nanocrystal aerogels as viable bone tissue scaffolds by Daniel A. Osorio, Bryan E. J. Lee, Jacek M. Kwiecien, Xiaoyue Wang, Iflah Shahid, Ariana L. Hurley, Emily D. Cranston and Kathryn Grandfield. Acta Biomaterialia Volume 87, 15 March 2019, Pages 152-165 DOI: https://doi.org/10.1016/j.actbio.2019.01.049

This paper is behind a paywall

Now for the Russian team.

National University of Science and Technology “MISIS” (formerly part of the Moscow Mining Academy)

These scientists have adopted a different strategy as you’ll see in the March 19, 2019 news item on Nanwerk, which, coincidentally, was published on the same day as the Canadian research,

Scientists from the National University of Science and Technology “MISIS” developed a nanomaterial, which will be able to rstore the internal structure of bones damaged due to osteoporosis and osteomyelitis. A special bioactive coating of the material helped to increase the rate of division of bone cells by 3 times. In the future, it can allow to abandon bone marrow transplantation and patients will no longer need to wait for suitable donor material.

A March 19, 2019 National University of Science and Technology (MISIS) press release (also on EurekAlert), which originated the news item, provides detail about the impetus for the research and the technique being developed,

Such diseases as osteoporosis and osteomyelitis cause irreversible degenerative changes in the bone structure. Such diseases require serious complex treatment and surgery and transplantation of the destroyed bone marrow in severe stages. Donor material should have a number of compatibility indicators and even close relationship with the donor cannot guarantee full compatibility.

Research group from the National University of Science and Technology “MISIS” (NUST MISIS), led by Anton Manakhov (Laboratory for Inorganic Nanomaterials) developed material that will allow to restore damaged internal bone structure without bone marrow transplantation.
It is based on nanofibers of polycaprolactone, which is biocompatible self-dissolvable material. Earlier, the same research group has already worked with this material: by adding antibiotics to the nanofibers, scientists have managed to create non-changeable healing bandages.

“If we want the implant to take, not only biocompatibility is needed, but also activation of the natural cell growth on the surface of the material. Polycaprolactone as such is a hydrophobic material, meaning, and cells feel uncomfortable on its surface. They gather on the smooth surface and divide extremely slow”, Elizaveta Permyakova, one of the co-authors and researcher at NUST MISIS Laboratory for Inorganic Nanomaterials, explains.

To increase the hydrophilicity of the material, a thin layer of bioactive film consisting of titanium, calcium, phosphorus, carbon, oxygen and nitrogen (TiCaPCON) was deposited on it. The structure of nanofibers identical to the cell surface was preserved. These films, when immersed in a special salt medium, which chemical composition is identical to human blood plasma, are able to form on its surface a special layer of calcium and phosphorus, which in natural conditions forms the main part of the bone. Due to the chemical similarity and the structure of nanofibers, new bone tissue begins to grow rapidly on this layer. Most importantly, polycaprolactone nanofibers dissolve, having fulfilled their functions. Only new “native” tissue remains in the bone.

In the experimental part of the study, the researchers compared the rate of division of osteoblastic bone cells on the surface of the modified and unmodified material. It was found that the modified material TiCaPCON has a high hydrophilicity. In contrast to the unmodified material, the cells on its surface felt clearly more comfortable, and divided three times faster.

According to scientists, such results open up great prospects for further work with modified polycaprolactone nanofibers as an alternative to bone marrow transplantation.

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

Bioactive TiCaPCON-coated PCL nanofibers as a promising material for bone tissue engineering by Anton Manakhov, Elizaveta S. Permyakova, Sergey Ershov, Alexander Sheveyko, Andrey Kovalskii, Josef Polčák, Irina Y. Zhitnyak, Natalia A. Gloushankova, Lenka Zajíčková, Dmitry V. Shtansky. Applied Surface Science Volume 479, 15 June 2019, Pages 796-802 DOI: https://doi.org/10.1016/j.apsusc.2019.02.163

This paper is behind a paywall.

A nanocomposite biomaterial heart valve from the University of British Columbia (Canada)

I wish the folks at the University of British Columbia (UBC) would include more technical/scientific information in their news releases about research. For those who do like a little more technical information, I included the paper’s abstract at the end of this post.

A March 25, 2019 news item on ScienceDaily trumpets the UBC (Okanagan campus) research,

Researchers at UBC have created the first-ever nanocomposite biomaterial heart-valve developed to reduce or eliminate complications related to heart transplants.

By using a newly developed technique, the researchers were able to build a more durable valve that enables the heart to adapt faster and more seamlessly.

A March 25, 2019 UBC news release (also on EurekAlert) by Patty Wellborn, which originated the news item, gives an accessible description of the ‘new’ valve,

Assistant Professor Hadi Mohammadi runs the Heart Valve Performance Laboratory (HVPL) through UBC Okanagan’s School of Engineering. Lead author on the study, he says the newly developed valve is an example of a transcatheter heart valve, a promising new branch of cardiology. These valves are unique because they can be inserted into a patient through small incisions rather than opening a patient’s chest–a procedure that is generally safer and much less invasive.

“Existing transcatheter heart valves are made of animal tissues, most often the pericardium membrane from a cow’s heart, and have had only moderate success to date,” explains Mohammadi. “The problem is that they face significant implantation risks and can lead to coronary obstruction and acute kidney injury.”

The new valve solves that problem by using naturally derived nanocomposites–a material assembled with a variety of very small components–including gels, vinyl and cellulose. The combination of their new material with the non-invasive nature of transcatheter heart valves makes this new design very promising for use with high-risk patients, according to Mohammadi.

“Not only is the material important but the design and construction of our valve means that it lowers stress on the valve by as much as 40 per cent compared to valves currently available,” says Dylan Goode, a graduate researcher at the HVPL. “It is uniquely manufactured in one continuous form, so it gains strength and flexibility to withstand the circulatory complications that can arise following transplantation.”

Working with researchers from Kelowna General Hospital and Western University, the valve will now undergo vigorous testing to perfect its material composition and design. The testing will include human heart simulators and large animal in-vivo studies. If successful, the valve will then proceed to clinical patient testing.

“This has the potential to become the new standard in heart valve replacement and to provide a safer, longer-term solution for many patients.”

The new design was highlighted in a paper published this month in the Journal of Engineering in Medicine with financial support from the Natural Sciences and Engineering Research Council of Canada [NSERC] .

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

Proposed percutaneous aortic valve prosthesis made of cryogel by Hadi Mohammadi, Dylan Goode, Guy Fradet, Kibret Mequanint. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2019; 095441191983730 DOI: 10.1177/0954411919837302 First Published March 20, 2019

This paper is behind a paywall.

As promised, here’s the abstract,

Transcatheter heart valves are promising for high-risk patients. Generally, their leaflets are made of pericardium stented in a Nitinol basket. Despite their relative success, they are associated with significant complications such as valve migration, implantation risks, stroke, coronary obstruction, myocardial infraction, acute kidney injury (which all are due to the release of detached solid calcific pieces in to the blood stream) and expected issues existing with tissue valves such as leaflet calcification. This study is an attempt to fabricate the first ever polymeric percutaneous valves made of cryogel following the geometry and mechanical properties of porcine aortic valve to address some of the above-mentioned shortcomings. A novel, one-piece, tricuspid percutaneous valve, consisting of leaflets made entirely from the hydrogel, polyvinyl alcohol cryogel reinforced by bacterial cellulose natural nanocomposite, attached to a Nitinol basket was developed and demonstrated. Following the natural geometry of the valve, a novel approach was applied based on the revolution about an axis of a hyperboloid shape. The geometry was modified based on avoiding sharp warpage of leaflets and removal of the central opening orifice area of the valve when valve is fully closed using the finite element analysis. The modified geometry was replaced by a cloud of (control) points and was essentially converted to Bezier surfaces for further adjustment. A cavity mold was then designed and fabricated to form the valve. The fabricated valve was sewn into the Nitinol basket which is covered by Dacron cloth. The models presented in this study merit further development and revisions for both aortic and mitral positions.

So, this new valve partially consists of bacterial cellulose and the design is based on porcine (pig) valves. Cellulose is the most abundant organic material on earth and if it forms part of the nanocomposite, I’d expect to see the word ‘nanocellulose’ mentioned somewhere. What puzzles me is the ‘bacterial cellulose’, a term that is unfamiliar to me. Anyone who cares to clarify the matter for me, please feel free to leave a comment.

Regarding the pig valve, I understand that heart patients who require valves have a choice of a pig valve or a mechanical valve. Apparently, people with porcine valves don’t need to take drugs to counteract rejection amongst other advantages but the valves do have a shorter life span (10 to 15 years) in addition to the other shortcomings mentioned in the abstract.

Assuming I properly understand the abstract, this ‘nanocomposite’ valve could combine the advantages of the mechanical and porcine valves while offering more durability than either one.

Again, should anyone care to increase my understanding of the valves and the advantages of this new one, please do leave a comment.

Ankle exoskeletons good for people who need to do a lot of walking or running on the job

For people who need a little extra ankle support, this might be useful in the, hopefully, not too distant future.

The new ankle exoskeleton design integrates into the shoe and under clothing. Submitted photo. Courtesy of Vanderbilt University Credit: Matthew Yandell

A March 22, 2019 news item on ScienceDaily announces this latest research,

A new lightweight, low-profile and inexpensive ankle exoskeleton could be widely used among elderly people, those with impaired lower-leg muscle strength and workers whose jobs require substantial walking or running.

Developed by Vanderbilt mechanical engineers, the device is believed to be the first ankle exoskeleton that could be worn under clothes without restricting motion. It does not require additional components such as batteries or actuators carried on the back or waist.

A March 21, 2019 Venderbilt University news release (also on EurekAlert but published March 22, 2019), offers more detail,

The study, published online by IEEE Transactions on Neural Systems & Rehabilitation Engineering, builds on a successful and widely cited ankle exoskeleton concept from other researchers in 2015.

“We’ve shown how an unpowered ankle exoskeleton could be redesigned to fit under clothing and inside/under shoes so it more seamlessly integrates into daily life,” said Matt Yandell, a mechanical engineering Ph.D. student and lead author of the study.

In a significant design advancement, the team invented an unpowered friction clutch mechanism that fits under the foot or shoe and is no thicker than a typical shoe insole. The complete device, which includes a soft shank sleeve and assistive spring, weighs just over one pound.

The unpowered ankle exoskeleton costs less than $100 to fabricate, without factoring in optimized design for manufacturing and economies of scale.

“Our design is lightweight, low profile, quiet, uses no motor or batteries, it is low cost to manufacture, and naturally adapts to different walking speeds to assist the ankle muscles,” said Karl Zelik, assistant professor of mechanical engineering and senior author on the study.

Zelik will be presenting this work next week at the Wearable Robotics Association Conference in Phoenix, Arizona [March 26-28, 2019].

The potential applications are broad, from helping aging people stay active to assisting recreational walkers, hikers or runners, he said.

“It could also help reduce fatigue in occupations that involve lots of walking, such as postal and warehouse workers, and soldiers in the field,” Zelik said.

Joshua Tacca, BE’18, also is a co-author. He is now a graduate student in the Integrative Physiology Department at the University of Colorado-Boulder. Several other Vanderbilt undergraduate engineering students also contributed to the device design and pilot testing.

I wonder if this device requires a particular kind of shoe. In any event, here’s a link to and a citation for the study,

Design of a Low Profile, Unpowered Ankle Exoskeleton That Fits Under Clothes: Overcoming Practical Barriers to Widespread Societal Adoption by Matthew B. Yandell, Joshua R. Tacca, and Karl E. Zelik. IEEE Transactions on Neural Systems & Rehabilitation Engineering 2019; 1 DOI: 10.1109/TNSRE.2019.2904924 Date of Publication: 14 March 2019 (early access)

This study appears to be behind a paywall

An art/science and a science event in Vancouver (Canada)

We’re closing off August 2019 with a couple of talks, Curiosity Collider features an art/science event and Café Scientifique features a discussion about protease research.

Collider Café: Art. Science. Hybrids. on August 21, 2019

From an August 14, 2019 Curiosity Collider announcement (received via email),

How can the hybrids of scientific studies and artistic practices – embroidery, botanical art, projection sculpture, and video storytelling – spark creativity and discoveries?

Our #ColliderCafe is a space for artists, scientists, makers, and anyone interested in art+science to meet, discover, and connect.

Are you curious? Join us at “Collider Cafe: Art. Science. Hybrids.” to explore how art and science intersect in the exploration of curiosity.

When: 8:00pm on Wednesday, August 21, 2019. Doors open at 7:30pm.
Where: Pizzeria Barbarella. 654 E Broadway, Vancouver, BC (Google Map).
Cost: $5-10 (sliding scale) cover at the door. Proceeds will be used to cover the cost of running this event, and to fund future Curiosity Collider events.

//Special thanks to Pizzeria Barbarella for hosting the upcoming Collider Cafe!//

With speakers: Heather Talbot (ecosystem, embroidery and felt art): Studying complex systems with thread
Katrina Vera Wong (botanical and climate research informed art): Flower Power
Kat Wadel (projection sculpture & plastic waste): Polymer Legacy
Lucas Kavanagh & Jesse Lupini; Avocado Video (science communication & video storytelling): Experiments in Digital Scientific Storytelling
Head to the Facebook event page – let us know you are coming and share this event with others! Follow updates on Instagram via @curiositycollider or #ColliderCafe. 
Looking for more Art+Science in Vancouver?

September 13, 14 We are excited to announce events for Her Story: Canadian Women Scientists, a film series dedicated to sharing the stories of Canadian women scientists. We will be hosting two screening events in September at the Annex. Get your tickets now!
August 15 Explore our relationships with waterways across Metro Vancouver at Living Legends of Vancouver: a premiere screening of short videos by students from the Emily Carr. This screening will be hosted by the Beaty Biodiversity Museum (admission by donation), and intermixed with interactive presentations and dialogue led by the artists. 
August 28 Our friends at Nerd Nite Vancouver is hosting Nerd Nite Goes to the Movies at the VIFF. The next event will focus on evolution. The event will be followed by a screening of Andrew Niccol’s Gattaca. Get tickets now!
Until September 29  New Media Gallery presents Winds, where artists explore how our perception and understanding of landscape can be interpreted through technology.  
Until November 10 CC friend Katrina Vera Wong (also speaker for Collider Cafe!), and Julya Hajnoczky will present their exhibition Closer at the Beaty Biodiversity Museum. Using different approaches – Hajnoczky with high-resolution still life photographs and Wong with sections of pressed or dried plants – both artists explore the enchanting world of the often overlooked in this unique joint exhibition

For more Vancouver art+science events, visit the Curiosity Collider events calendar.

Café Scientifique: From tadpole tails to diagnosing disease – the evolution of protease research, August 27, 2019

From an August 14, 2019 Café Scientifique announcement (received via email),

Our next café will happen on Tuesday, August 27th at 7:30pm in the back room at Yagger’s Downtown (433 W Pender). Our speaker for the evening will be  Dr. Georgina Butler from the Centre for Blood Research at UBC [University of British Columbia].


From tadpole tails to diagnosing disease – the evolution of protease research  
 
Proteases are enzymes that cut other proteins. Humans have 560 different proteases – why so many? what are they doing? We know that too much protease activity can be detrimental in diseases such as cancer and arthritis, but failed efforts to stop cancer spread by blocking proteases has contributed to the realization that some cuts are essential. In the era of “big data”, at UBC we have developed new techniques (degradomics) to study proteases on a global scale to determine what they really do in health and disease. Hopefully this information will enable us to identify new drug targets as well as novel biomarkers to diagnose or monitor disease.

Dr. Butler completed her undergraduate degree in Biochemistry (with Studies in Italy) at the University of Kent at Canterbury, and her PhD in Biochemistry at the University of Leicester in the UK. She came to UBC as a Wellcome Trust Travelling Fellow in 1999 for 2 years. Still here, she is a Research Associate at the Centre for Blood Research and in Oral, Biological and Medical Sciences at UBC, where she studies novel roles of proteases in health and disease. 

We hope to see you there!

Your Café Sci Vancouver Organizers

You can find Dr. Butler’s UBC profile page here.