Carbon nanotubes as sensors in the body

Rachel Ehrenberg has written an Aug. 21, 2015 news item about the latest and greatest carbon nanotube-based biomedical sensors for the journal Nature,

The future of medical sensors may be going down the tubes. Chemists are developing tiny devices made from carbon nanotubes wrapped with polymers to detect biologically important compounds such as insulin, nitric oxide and the blood-clotting protein fibrinogen. The hope is that these sensors could simplify and automate diagnostic tests.

Preliminary experiments in mice, reported by scientists at a meeting of the American Chemical Society in Boston, Massachusetts, this week [Aug. 16 – 20, 2015], suggest that the devices are safe to introduce into the bloodstream or implant under the skin. Researchers also presented data showing that the nanotube–polymer complexes could measure levels of large molecules, a feat that has been difficult for existing technologies.

Ehrenberg focuses on one laboratory in particular (Note: Links have been removed),

“Anything the body makes, it is meant to degrade,” says chemical engineer Michael Strano, whose lab at the Massachusetts Institute of Technology (MIT) in Cambridge is behind much of the latest work1. “Our vision is to make a sensing platform that can monitor a whole range of molecules, and do it in the long term.”

To design one sensor, MIT  researchers coated nanotubes with a mix of polymers and nucleotides and screened for configurations that would bind to the protein fibrinogen. This large molecule is important for building blood clots; its concentration can indicate bleeding disorders, liver disease or impending cardiovascular trouble. The team recently hit on a material that worked — a first for such a large molecule, according to MIT nanotechnology specialist Gili Bisker. Bisker said at the chemistry meeting that the fibrinogen-detecting nanotubes could be used to measure levels of the protein in blood samples, or implanted in body tissue to detect changing fibrinogen levels that might indicate a clot.

The MIT team has also developed2 a sensor that can be inserted beneath the skin to monitor glucose or insulin levels in real time, Bisker reported. The team imagines putting a small patch that contains a wireless device on the skin just above the embedded sensor. The patch would shine light on the sensor and measure its fluorescence, then transmit that data to a mobile phone for real-time monitoring.

Another version of the sensor, developed3 at MIT by biomedical engineer Nicole Iverson and colleagues, detects nitric oxide. This signalling molecule typically indicates inflammation and is associated with many cancer cells. When embedded in a hydrogel matrix, the sensor kept working in mice for more than 400 days and caused no local inflammation, MIT chemical engineer Michael Lee reported. The nitric oxide sensors also performed well when injected into the bloodstreams of mice, successfully passing through small capillaries in the lungs, which are an area of concern for nanotube toxicity. …

There’s at least one corporate laboratory (Google X), working on biosensors although their focus is a little different. From a Jan. 9, 2015 article by Brian Womack and Anna Edney for BloombergBusiness,

Google Inc. sent employees with ties to its secretive X research group to meet with U.S. regulators who oversee medical devices, raising the possibility of a new product that may involve biosensors from the unit that developed computerized glasses.

The meeting included at least four Google workers, some of whom have connections with Google X — and have done research on sensors, including contact lenses that help wearers monitor their biological data. Google staff met with those at the Food and Drug Administration who regulate eye devices and diagnostics for heart conditions, according to the agency’s public calendar. [emphasis mine]

This approach from Google is considered noninvasive,

“There is actually one interface on the surface of the body that can literally provide us with a window of what happens inside, and that’s the surface of the eye,” Parviz [Babak Parviz, … was involved in the Google Glass project and has talked about putting displays on contact lenses, including lenses that monitor wearer’s health]  said in a video posted on YouTube. “It’s a very interesting chemical interface.”

Of course, the assumption is that all this monitoring is going to result in  healthier people but I can’t help thinking about an old saying ‘a little knowledge can be a dangerous thing’. For example, we lived in a world where bacteria roamed free and then we learned how to make them visible, determined they were disease-causing, and began campaigns for killing them off. Now, it turns out that at least some bacteria are good for us and, moreover, we’ve created other, more dangerous bacteria that are drug-resistant. Based on the bacteria example, is it possible that with these biosensors we will observe new phenomena and make similar mistakes?

Self-assembling copper and physiology

An Aug. 24, 2015 news item on Nanowerk highlights work at Louisiana Tech University (US) on self-assembling copper nanocomposites in liquid form,

Faculty at Louisiana Tech University have discovered, for the first time, a new nanocomposite formed by the self-assembly of copper and a biological component that occurs under physiological conditions, which are similar those found in the human body and could be used in targeted drug delivery for fighting diseases such as cancer.

The team, led by Dr. Mark DeCoster, the James E. Wyche III Endowed Associate Professor in Biomedical Engineering at Louisiana Tech, has also discovered a way for this synthesis to be carried out in liquid form. This would allow for controlling the scale of the synthesis up or down, and to grow structures with larger features, so they can be observed.

An Aug. 24, 2015 Louisiana Tech University news release by Dave Guerin, which originated the news item, describes possible future  applications and the lead researcher’s startup company,

“We are currently investigating how this new material interacts with cells,” said DeCoster. “It may be used, for example for drug delivery, which could be used in theory for fighting diseases such as cancer. Also, as a result of the copper component that we used, there could be some interesting electronics, energy, or optics applications that could impact consumer products. In addition, copper has some interesting and useful antimicrobial features.

“Finally, as the recent environmental spill of mining waste into river systems showed us, metals, including copper, can sometimes make their way into freshwater systems, so our newly discovered metal-composite methods could provide a way to “bind up” unwanted copper into a useful or more stable form.”

DeCoster said there were two aspects of this discovery that surprised him and his research team. First, they found that once formed, these copper nanocomposites were incredibly stable both in liquid or dried form, and remained stable for years. “We have been carrying out this research for at least four years and have a number of samples that are at least two years old and still stable,” DeCoster said.

Second, DeCoster’s group was very surprised that these composites are resistant to agglomeration, which is the process by which material clumps or sticks together.

“This is of benefit because it allows us to work with individual structures in order to separate or modify them chemically,” explains DeCoster. “When materials stick together and clump, as many do, it is much harder to work with them in a logical way. Both of these aspects, however, fit with our hypothesis that the self-assembly that we have discovered is putting positively charged copper together with negatively charged sulfur-containing cystine.”

The research discovery was a team effort that included DeCoster and Louisiana Tech students at the bachelor, master and doctoral level. “The quality of my team in putting together a sustained effort to figure out what was needed to reproducibly carry out the new self-assembly methods and to simplify them really speaks well as to what can be accomplished at Louisiana Tech University,” DeCoster said. “Furthermore, the work is very multi-disciplinary, meaning that it required nanotechnology as well as biological and biochemical insights to make it all work, as well as some essential core instrumentation that we have at Louisiana Tech.”

DeCoster says the future of this research has some potentially high impacts. He and his team are speaking with colleagues and collaborators about how to test these new nanocomposites for applications in bioengineering and larger composites such as materials that would be large enough to be hand-held.

“Our recent publication of the work could generate some interest and new ideas,” said DeCoster. “We are working on new proposals to fund the research and to keep it moving forward. We are currently making these materials on an ‘as needed’ basis, knowing that they can be stored once generated, and if we discover new uses for the nanocomposites, then applications for the materials could lead to income generation through a start-up company that I have formed.”

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

MediumGeneration of Scalable, Metallic High-Aspect Ratio Nanocomposites in a Biological Liquid Medium by Kinsey Cotton Kelly, Jessica R. Wasserman, Sneha Deodhar, Justin Huckaby, and Mark A. DeCoster. J. Vis. Exp. [Journal of Visual Experimentation; JoVE] (101), e52901, doi:10.3791/52901 (2015).

This paper/video is behind a paywall.

The Gaza is running out of water by 2016 if the United Nations predictions are correct

If the notion that people are in imminent danger of dying from thirst isn’t compelling enough, there’s this account of the situation and a possible solution in an August 24, 2015 posting by observers, Abou Assi and Majdi Fathi, with journalist, Dorothée Myriam Kellou for,

Each year, Gaza’s population uses 180 million cubic metres of water but only has capacity for 60 million cubic metres of water usage per year. Running out of water is a constant fear for Gazans.

To understand the context of the crisis, we first spoke to our Observer Majdi Fathi, a photographer who lives in Gaza. He described the daily struggles of living in a place with a shortage of potable water.

The water that comes out of the taps in Gaza is too salty to drink. We only use it for washing. We have to buy bottled water to drink. Each family goes to water vendors. [Editor’s note : Often, families buy water from private companies who run desalination plants with little regulation. Though the water quality is often criticised, it’s still very expensive]. People frequently pay about $2 for 500 litres of water. There are ten people in my family and we can live on 500 litres for about 25 days. Though the authorities give some free water to the very poorest, it’s not enough.

We are all worried about the water shortage. Often, the taps run dry and we end up having to use the drinking water that we purchased for cleaning. Buying water from vendors is not a long-term, sustainable solution!

In a June 25, 2013 posting, I included (in an update) some information about the Gaza situation in the context of water issues in Israel and a special project with the University of Chicago designed to address those issues,

ETA June 27, 2013: There is no hint in the University of Chicago news releases that these water projects will benefit any parties other than Israel and the US but it is tempting to hope that this work might also have an impact in Palestine given its current water crisis there as described in a June 26, 2013 news item in the World Bulletin (Note: Links have been removed),

A tiny wedge of land jammed between Israel, Egypt and the Mediterranean sea, the Gaza Strip is heading inexorably into a water crisis that the United Nations says could make the Palestinian enclave unliveable in just a few years.

With 90-95 percent of the territory’s only aquifer contaminated by sewage, chemicals and seawater, neighbourhood desalination facilities and their public taps are a lifesaver for some of Gaza’s 1.6 million residents.

But these small-scale projects provide water for only about 20 percent of the population, forcing many more residents in the impoverished Gaza Strip to buy bottled water at a premium.

“There is a crisis. There is a serious deficit in the water resources in Gaza and there is a serious deterioration in the water quality,” said Rebhi El Sheikh, deputy chairman of the Palestinian Water Authority (PWA).

A NASA study of satellite data released this year showed that between 2003 and 2009 the region lost 144 cubic km of stored freshwater – equivalent to the amount of water held in the Dead Sea – making an already bad situation much worse.

But the situation in Gaza is particularly acute, with the United Nations warning that its sole aquifer might be unusable by 2016, with the damage potentially irreversible by 2020.

Abou Assi, a Palestinian engineer, thinks he may have a solution (from the Aug. 24, 2015 posting),

The water table, which is the main source of drinking water in Gaza, is being over-exploited and is also polluted by both nitrates used in agriculture and by sea water. Gaza’s groundwater could run out as soon as next year, according to the United Nations.

While I was working on my masters in engineering at the Islamic University in Gaza, I started looking for a radical solution to the problem. Seeing as Gaza is located on the shores of the Mediterranean, I started considering a filtration system that could desalinate sea water.

There are seven different desalination plants in Gaza. They each produce between 45 and 80 cubic metres of water an hour. The problem is that all of these factories use the reverse osmosis procedure [Editor’s note: This is a water purification system that uses a semipermeable membrane to remove larger particles, including salt molecules, from water molecules].

Even though the method is ingenious, it requires a lot of energy. This is a problem in Gaza, because we also have a major energy shortage. Our power plant, which provides Gaza with about a third of its energy, regularly stops working due to fuel shortages.

My team and I conducted 170 experiments in 14 months before we managed to create a machine that reduced the salinity of the seawater enough to make it drinkable.

The machine is very simple: it pumps sea water very quickly through iron pipes. The water passes through electrical boxes that push the water through membranes made from nanomaterials. The membranes have tiny, microscopic pores that block the sodium chloride (salt) molecules but allow the water molecules to go through. After the water is filtered, the useful minerals are re-injected. After all this, the water that comes out of the taps is clean enough to drink!

With this machine, it’s possible to treat one cubic metre of water per day, using 60% less energy than with the old system. The water meets the quality standards of the World Health Organisation, which puts limits on a number of substances, including chlorine, limestone, lead, nitrates, pesticides and bacteria. For now, some so-called “drinkable” water in Gaza has nitrate levels that can reach up to 220 mg per litre even though the WHO recommends a limit of 50 mg per litre. Poorly treated drinking water can cause many health problems, especially for children. [Editor’s note: The WHO recently noted an increase in cases of children with diarrhea in Gaza].

Assi has gone into debt to finance his research despite the fact he has received grants for this work (from the Aug. 24, 2015 posting),

In order to transition from the prototype to a practical application, I need more financial support. I would like to create a model of a smaller version that could be put into people’s homes in Gaza. In order to develop this, all I need is about $20,000.

That said, in order to really resolve the drinking water crisis across Gaza, we would need to build a desalination plant that uses this technique. That would be expensive — about $300,000 million – and there would always be the fear that the plant would be bombed, like with the power plant.

We have attempted to discuss our ideas with officials in both Gaza and Ramallah but, for the time being, we have received no response. We hope for support both from Palestinian institutions and from the international community.

There doesn’t yet seem to be a website or Facebook page or other means of contacting and/or lending other kinds of support to Assi. Hopefully, he will have something soon.

In a February 24, 2014 posting, I featured a nanotechnology laboratory in Oman where they were studying and working to develop desalination technologies. (I noticed that Assi received a grant for his work from the  Middle East Desalination Research Center in Oman.)

Corrections: Hybrid Photonic-Nanomechanical Force Microscopy uses vibration for better chemical analysis

*ETA August 27, 2015: I’ve received an email from one of the paper’s authors (RH Farahi of the US Oak Ridge National Laboratory [ORNL]) who claims some inaccuracies in this piece.  The news release supplied by the University of Central Florida states that Dr. Tetard led the team and that is not so. According to Dr. Farahi, she had a postdoctoral position on the team which she left two years ago. You might also get the impression that some of the work was performed at the University of Central Florida. That is not so according to Dr. Farahi.  As a courtesy Dr. Tetard was retained as first author of the paper.

I suspect some of the misunderstanding was due to overeagerness and/or time pressures. Whoever wrote the news release may have made some assumptions. It’s very easy to make a mistake when talking to an ebullient scientist who can unintentionally lead you to believe something that’s not so. I worked in a high tech company and believed that there was some new software being developed which turned out to be a case of high hopes. Luckily, I said something that triggered a rapid rebuttal to the fantasies. Getting back to this situation, other contributing factors could include the writer not having time to get the news release reviewed the scientist or the scientist skimming the release and missing a few bits due to time pressure.

The August 10, 2015 ORNL news release with all the correct details has been added to the end of this post.*

A researcher at the University of Central Florida (UCF) has developed a microscope that uses vibrations for better analysis of chemical composition. From an Aug. 10, 2015 news item on Nanowerk,

It’s a discovery that could have promising implications for fields as varied as biofuel production, solar energy, opto-electronic devices, pharmaceuticals and medical research.

“What we’re interested in is the tools that allow us to understand the world at a very small scale,” said UCF professor Laurene Tetard, formerly of the Oak Ridge National Laboratory. “Not just the shape of the object, but its mechanical properties, its composition and how it evolves in time.”

An Aug. 10, 2015 UCF news release (also on EurekAlert), which originated the news item, describes the limitations of atomic force microscopy and gives a few details about the hybrid microscope (Note: A link has been removed),

For more than two decades, scientists have used atomic force microscopy – a probe that acts like an ultra-sensitive needle on a record player – to determine the surface characteristics of samples at the microscopic scale. A “needle” that comes to an atoms-thin point traces a path over a sample, mapping the surface features at a sub-cellular level [nanoscale].

But that technology has its limits. It can determine the topographical characteristics of [a] sample, but it can’t identify its composition. And with the standard tools currently used for chemical mapping, anything smaller than roughly half a micron is going to look like a blurry blob, so researchers are out of luck if they want to study what’s happening at the molecular level.

A team led by Tetard has come up with a hybrid form of that technology that produces a much clearer chemical image. As described Aug. 10 in the journal Nature Nanotechnology, Hybrid Photonic-Nanomechanical Force Microscopy (HPFM) can discern a sample’s topographic characteristics together with the chemical properties at a much finer scale.

The HPFM method is able to identify materials based on differences in the vibration produced when they’re subjected to different wavelengths of light – essentially a material’s unique “fingerprint.”

“What we are developing is a completely new way of making that detection possible,” said Tetard, who has joint appointments to UCF’s Physics Department, Material Science and Engineering Department and the NanoScience Technology Center.

The researchers proved the effectiveness of HPFM while examining samples from an eastern cottonwood tree, a potential source of biofuel. By examining the plant samples at the nanoscale, the researchers for the first time were able to determine the molecular traits of both untreated and chemically processed cottonwood inside the plant cell walls.

The research team included Tetard; Ali Passian, R.H. Farahi and Brian Davison, all of Oak Ridge National Laboratory; and Thomas Thundat of the University of Alberta.

Long term, the results will help reveal better methods for producing the most biofuel from the cottonwood, a potential boon for industry. Likewise, the new method could be used to examine samples of myriad plants to determine whether they’re good candidates for biofuel production.

Potential uses of the technology go beyond the world of biofuel. Continued research may allow HPFM to be used as a probe so, for instance, it would be possible to study the effect of new treatments being developed to save plants such as citrus trees from bacterial diseases rapidly decimating the citrus industry, or study fundamental photonically-induced processes in complex systems such as in solar cell materials or opto-electronic devices.

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

Opto-nanomechanical spectroscopic material characterization by L. Tetard, A. Passian, R. H. Farahi, T. Thundat, & B. H. Davison. Nature Nanotechnology (2015) doi:10.1038/nnano.2015.168 Published online 10 August 2015

This paper is behind a paywall.

*ETA August 27, 2015:

August 10, 2015 ORNL news release (Note: Funding information and a link to the paper [previously given] have been removed):

A microscope being developed at the Department of Energy’s Oak Ridge National Laboratory will allow scientists studying biological and synthetic materials to simultaneously observe chemical and physical properties on and beneath the surface.

The Hybrid Photonic Mode-Synthesizing Atomic Force Microscope is unique, according to principal investigator Ali Passian of ORNL’s Quantum Information System group. As a hybrid, the instrument, described in a paper published in Nature Nanotechnology, combines the disciplines of nanospectroscopy and nanomechanical microscopy.

“Our microscope offers a noninvasive rapid method to explore materials simultaneously for their chemical and physical properties,” Passian said. “It allows researchers to study the surface and subsurface of synthetic and biological samples, which is a capability that until now didn’t exist.”

ORNL’s instrument retains all of the advantages of an atomic force microscope while simultaneously offering the potential for discoveries through its high resolution and subsurface spectroscopic capabilities.

“The originality of the instrument and technique lies in its ability to provide information about a material’s chemical composition in the broad infrared spectrum of the chemical composition while showing the morphology of a material’s interior and exterior with nanoscale – a billionth of a meter – resolution,” Passian said.

Researchers will be able to study samples ranging from engineered nanoparticles and nanostructures to naturally occurring biological polymers, tissues and plant cells.

The first application as part of DOE’s BioEnergy Science Center was in the examination of plant cell walls under several treatments to provide submicron characterization. The plant cell wall is a layered nanostructure of biopolymers such as cellulose. Scientists want to convert such biopolymers to free the useful sugars and release energy.

An earlier instrument, also invented at ORNL, provided imaging of poplar cell wall structures that yielded unprecedented topological information, advancing fundamental research in sustainable biofuels.

Because of this new instrument’s impressive capabilities, the researcher team envisions broad applications.
“An urgent need exists for new platforms that can tackle the challenges of subsurface and chemical characterization at the nanometer scale,” said co-author Rubye Farahi. “Hybrid approaches such as ours bring together multiple capabilities, in this case, spectroscopy and high-resolution microscopy.”

Looking inside, the hybrid microscope consists of a photonic module that is incorporated into a mode-synthesizing atomic force microscope. The modular aspect of the system makes it possible to accommodate various radiation sources such as tunable lasers and non-coherent monochromatic or polychromatic sources.

Fixed: The Science/Fiction of Human Enhancement

First the news, Fixed: The Science/Fiction of Human Enhancement is going to be broadcast on KCTS 9 (PBS [Public Broadcasting Service] station for Seattle/Yakima) on Wednesday, Aug. 26, 2015 at 7 pm PDT. From the KCTS 9 schedule,

From botox to bionic limbs, the human body is more “upgradeable” than ever. But how much of it can we alter and still be human? What do we gain or lose in the process? Award-winning documentary, Fixed: The Science/Fiction of Human Enhancement, explores the social impact of human biotechnologies. Haunting and humorous, poignant and political, Fixed rethinks “disability” and “normalcy” by exploring technologies that promise to change our bodies and minds forever.

This 2013 documentary has a predecessor titled ‘Fixed’, which I wrote about in an August 3, 2010 posting. The director for both ‘Fixeds’ is Regan Brashear.

It seems the latest version of Fixed builds on the themes present in the first, while integrating the latest scientific work (to 2013) in the field of human enhancement (from my August 3, 2010 posting),

As for the film, I found this at the University of California, Santa Cruz,

Fixed is a video documentary that explores the burgeoning field of “human enhancement” technologies from the perspective of individuals with disabilities. Fixed uses the current debates surrounding human enhancement technologies (i.e. bionic limbs, brain machine interfaces, prenatal screening technologies such as PGD or pre-implantation genetic diagnosis, etc.) to tackle larger questions about disability, inequality, and citizenship. This documentary asks the question, “Will these technologies ‘liberate’ humanity, or will they create even more inequality?”

You can find out more about the 2013 Fixed on its website or Facebook page (they list opportunities in the US, in Canada, and internationally to see the documentary). There is also a listing of PBS broadcasts available from the Fixed: The Science/Fiction of Human Enhancement Press page.

I recognized two names from the cast list on the Internet Movie Database (IMDB) page for Fixed: The Science/Fiction of Human Enhancement, Gregor Wolbring (he also appeared in the first ‘Fixed’) and Hugh Herr.

Gregor has been mentioned here a few times in connection with human enhancement. A Canadian professor at the University of Calgary, he’s active in the field of bioethics and you can find out more about Gregor and his work here.

Hugh Herr was first mentioned here in a January 30, 2013 posting titled: The ultimate DIY: ‘How to build a robotic man’ on BBC 4. He is a robotocist at the Massachusetts Institute of Technology (MIT).

The two men offering contrasting perspectives, Gregor Wolbring, ‘we should re-examine the notion that some people are impaired and need to be fixed’,  and Hugh Herr, ‘we will eliminate all forms of impairment’. Hopefully, the 2013 documentary has managed to present more of the nuances than I have.

Graphene gains metallic powers after laser-burning

Rice University (Texas, US) researchers have developed a technique for embedding metallic nanoparticles in graphene with the hope of one day replacing platinum catalysts in fuel cells. From an August 20, 2015 news item on ScienceDaily,

Laser-induced graphene, created by the Rice lab of chemist James Tour last year, is a flexible film with a surface of porous graphene made by exposing a common plastic known as polyimide to a commercial laser-scribing beam. The researchers have now found a way to enhance the product with reactive metals.

An August 20, 2015 Rice University news release (also on EurekAlert), which originated the news item, provides further description,

With the discovery, the material that the researchers call “metal oxide-laser induced graphene” (MO-LIG) becomes a new candidate to replace expensive metals like platinum in catalytic fuel-cell applications in which oxygen and hydrogen are converted to water and electricity.

“The wonderful thing about this process is that we can use commercial polymers, with simple inexpensive metal salts added,” Tour said. “We then subject them to the commercial laser scriber, which generates metal nanoparticles embedded in graphene. So much of the chemistry is done by the laser, which generates graphene in the open air at room temperature.

“These composites, which have less than 1 percent metal, respond as ‘super catalysts’ for fuel-cell applications. Other methods to do this take far more steps and require expensive metals and expensive carbon precursors.”

Initially, the researchers made laser-induced graphene with commercially available polyimide sheets. Later, they infused liquid polyimide with boron to produce laser-induced graphene with a greatly increased capacity to store an electrical charge, which made it an effective supercapacitor.

For the latest iteration, they mixed the liquid and one of three concentrations containing cobalt, iron or molybdenum metal salts. After condensing each mixture into a film, they treated it with an infrared laser and then heated it in argon gas for half an hour at 750 degrees Celsius.

That process produced robust MO-LIGs with metallic, 10-nanometer particles spread evenly through the graphene. Tests showed their ability to catalyze oxygen reduction, an essential chemical reaction in fuel cells. Further doping of the material with sulfur allowed for hydrogen evolution, another catalytic process that converts water into hydrogen, Tour said.

“Remarkably, simple treatment of the graphene-molybdenum oxides with sulfur, which converted the metal oxides to metal sulfides, afforded a hydrogen evolution reaction catalyst, underscoring the broad utility of this approach,” he said.

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

In situ Formation of Metal Oxide Nanocrystals Embedded in Laser-Induced Graphene by Ruquan Ye, Zhiwei Peng, Tuo Wang, Yunong Xu, Jibo Zhang, Yilun Li, Lizanne G. Nilewski, Jian Lin, and James M. Tour. ACS Nano, Just Accepted Manuscript DOI: 10.1021/acsnano.5b04138 Publication Date (Web): August 18, 2015
Copyright © 2015 American Chemical Society

This paper is open access provided you have an ACS ID, which is a free registration. ACS is the American Chemical Society.

Foldable glass (well, there’s some plastic too)

Michael Berger has written a fascinating Aug. 11, 2015 Nanowerk Spotlight article on folding glass,

Have you ever heard about foldable glass?


Glass is notorious for its brittleness. Although industry has developed ultra-thin (∼0.1 mm), flexible glass (like Corning’s Willow® Glass) that can be bent for applications liked curved TV and smartphone displays, fully foldable glass had not been demonstrated. Until now.

Khang [Dahl-Young Khang, an Associate Professor in the Department of Materials Science and Engineering at Yonsei University] and his group have now demonstrated substrate platforms of glass and plastics, which can be reversibly and repeatedly foldable at pre designed location(s) without any mechanical failure or deterioration in device performances.

“We have engineered the substrates to have thinned parts on which the folding deformation should occur,” Moon Jong Han, first author of the paper a graduate student in Khang’s lab, says. “This localizes the deformation strain on those thinned parts only.”

He adds that this approach to engineering substrates has another advantage regarding device materials: “There is no need to adopt any novel materials such as nanowires, carbon nanotubes, graphene, etc. Rather, all the conventional materials that have been used for high-performance devices can be directly applied on our engineered substrates.”

Intriguingly, even ITO (indium tin oxide), a very brittle transparent conducting oxide, can be used as electrode on this novel foldable glass platform.

What makes the approach especially intriguing is the ability to reverse the fold and that it doesn’t require special nanomaterials, such as carbon nanotubes, etc. From Berger’s Aug. 11, 2015 article,

The width of the thinned parts, the gap width, plays the key role in implementing dual foldability. The other key element is the asymmetric design of the gap width for the second folding.

The researchers achieved foldability, in part, by copying a technique used for folding mats and oriental hinge-less screens which have thinned areas to allow folding.

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

Glass and Plastics Platforms for Foldable Electronics and Displays by Moon Jung Han and Dahl-Young Khang. Advanced Materials DOI: 10.1002/adma.201501060 First published: 21 July 2015

This paper is behind a paywall.

Berger’s article is not only fascinating, it is also illustrated with some images provided by the researchers.

ISEA (International Symposium on Electronic Arts) 2015 and the pronoun ‘I’

The 2015 International Symposium on Electronic Arts (or ISEA 2015) held  in Vancouver ended yesterday, Aug. 19, 2015. It was quite an experience both as a participant and as a presenter (mentioned in my Aug. 14, 2015 posting, Sneak peek: Steep (1): a digital poetry of gold nanoparticles). Both this ISEA and the one I attended previously in 2009 (Belfast, Northern Ireland, and Dublin, Ireland) were jampacked with sessions, keynote addresses, special events, and exhibitions of various artworks. Exhilarating and exhausting, that is the ISEA experience for me and just about anyone else I talked to here in Vancouver (Canada). In terms of organization, I have to give props to the Irish. Unfortunately, the Vancouver team didn’t seem to have given their volunteers any training and technical difficulties abounded. Basics such as having a poster outside a room noting what session was taking place, signage indicating which artist’s work was being featured, and good technical support (my guy managed to plug in a few things but seemed disinclined or perhaps didn’t have the technical expertise (?) to troubleshoot prior to the presentation) seemed elusive (a keynote presentation had to be moved due to technical requirements [!] plus no one told the volunteer staff who consequently misdirected people). Ooops.

Despite the difficulties, people remained enthusiastic and that’s a tribute to both the participants and, importantly, the organizers. The Vancouver ISEA was a huge undertaking with over 1000 presentation submissions made and over 1800 art work submissions. They had 900+ register and were the first ISEA able to offer payment to artists for their installations. Bravo to Philippe Pasquier, Thecla Schiphorst, Kate Armstrong, Malcolm Levy, and all the others who worked hard to pull this off.

Moving on to ‘I’, while the theme for ISEA 2015 was Disruption, I noticed a number of presentations focused on biology and on networks (in particular, generative networks). In some ways this parallels what’s happening in the sciences where more notice is being given to networks and network communications of all sorts.  For example, there’s an Aug. 19, 2015 news item on ScienceDaily suggesting that our use of the pronoun ‘I’ may become outdated.  What we consider to be an individual may be better understood as a host for a number of communities or networks,

Recent microbiological research has shown that thinking of plants and animals, including humans, as autonomous individuals is a serious over-simplification.

A series of groundbreaking studies have revealed that what we have always thought of as individuals are actually “biomolecular networks” that consist of visible hosts plus millions of invisible microbes that have a significant effect on how the host develops, the diseases it catches, how it behaves and possibly even its social interactions.

“It’s a case of the whole being greater than the sum of its parts,” said Seth Bordenstein, associate professor of biological sciences at Vanderbilt University, who has contributed to the body of scientific knowledge that is pointing to the conclusion that symbiotic microbes play a fundamental role in virtually all aspects of plant and animal biology, including the origin of new species.

In this case, the parts are the host and its genome plus the thousands of different species of bacteria living in or on the host, along with all their genomes, collectively known as the microbiome. (The host is something like the tip of the iceberg while the bacteria are like the part of the iceberg that is underwater: Nine out of every 10 cells in plant and animal bodies are bacterial. But bacterial cells are so much smaller than host cells that they have generally gone unnoticed.)

An Aug. 19, 2015 Vanderbilt University news release, which originated the news item, describes this provocative idea (no more ‘I’)  further,

Microbiologists have coined new terms for these collective entities — holobiont — and for their genomes — hologenome. “These terms are needed to define the assemblage of organisms that makes up the so-called individual,” said Bordenstein.

In the article “Host Biology in Light of the Microbiome: Ten Principles of Holobionts and Hologenomes” published online Aug. 18 [2015] in the open access journal PLOS Biology, Bordenstein and his colleague Kevin Theis from the University of Michigan take the general concepts involved in this new paradigm and break them down into underlying principles that apply to the entire field of biology.

They make specific and refutable predictions based on these principles and call for other biologists to test them theoretically and experimentally.

“One of the basic expectations from this conceptual framework is that animal and plant experiments that do not account for what is happening at the microbiological level will be incomplete and, in some cases, will be misleading as well,” said Bordenstein.

The first principle they advance is that holobionts and hologenomes are fundamental units of biological organization.

Another is that evolutionary forces such as natural selection and drift may act on the hologenome not just on the genome. So mutations in the microbiome that affect the fitness of a holobiont are just as important as mutations in the host’s genome. However, they argue that this does not change the basic rules of evolution but simply upgrades the types of biological units that the rules may act upon.

Although it does not change the basic rules of evolution, holobionts do have a way to respond to environmental challenges that is not available to individual organisms: They can alter the composition of their bacterial communities. For example, if a holobiont is attacked by a pathogen that the host cannot defend against, another symbiont may fulfill the job by manufacturing a toxin that can kill the invader. In this light, the microbes are as much part of the holobiont immune system as the host immune genes themselves.

According to Bordenstein, these ideas are gaining acceptance in the microbiology community. At the American Society of Microbiology General Meeting in June [2015], he convened the inaugural session on “Holobionts and Their Hologenomes” and ASM’s flagship journal mBio plans to publish a special issue on the topic in the coming year. [emphases are mine]

However, adoption of these ideas has been slower in other fields.

“Currently, the field of biology has reached an inflection point. The silos of microbiology, zoology and botany are breaking down and we hope that this framework will help further unify these fields,” said Bordenstein.

Not only will this powerful holistic approach affect the basic biological sciences but it also is likely to impact the practice of personalized medicine as well, Bordenstein said.

Take the missing heritability problem, for example. Although genome-wide studies have provided valuable insights into the genetic basis of a number of simple diseases, they have only found a small portion of the genetic causes of a number of more complex conditions such as autoimmune and metabolic diseases.

These may in part be “missing” because the genetic factors that cause them are in the microbiome, he pointed out.

“Instead of being so ‘germophobic,’ we need to accept the fact that we live in and benefit from a microbial world. We are as much an environment for microbes as microbes are for us,” said Bordenstein.

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

Host Biology in Light of the Microbiome: Ten Principles of Holobionts and Hologenomes by Seth R. Bordenstein and Kevin R. Theis. PLOS DOI: 10.1371/journal.pbio.1002226 Published: August 18, 2015

This is an open access paper.

It’s intriguing to see artists and scientists exploring ideas that resonate with each other. In fact, ISEA 2015 hosted a couple of sessions on BioArt, as well as, having sessions devoted to networks. While, I wasn’t thinking about networks or biological systems when I wrote my poem on gold nanoparticles, I did pose this possibility (how we become the sum of our parts) at the end:

Nature’s alchemy
breathing them
eating them
drinking them
we become gold
discovering what we are

As for how Raewyn handled the idea, words fail, please do go here to see the video here.

Wound healing with cellulose acetate nanofibres

This work on cellulose acetate nanofibres and wound healing (tested on mice) comes from Egypt according to an Aug. 10, 2015 news item on ScienceDaily,

People with diabetes mellitus often suffer from impaired wound healing. Now, scientists in Egypt have developed antibacterial nanofibres of cellulose acetate loaded with silver that could be used in a new type of dressing to promote tissue repair.

An Aug. 10, 2015 Inderscience Publishers press release on the Alpha Galileo website, which originated the news item, provides more detail about the research,

Thanaa Ibrahim Shalaby and colleagues, Nivan Mahmoud Fekry, Amal Sobhy El Sodfy, Amel Gaber El Sheredy and Maisa El Sayed Sayed Ahmed Moustafa, at Alexandria University, prepared nanofibres from cellulose acetate, an inexpensive and easily fabricated, semisynthetic polymer used in everything from photographic film to coatings for eyeglasses and even cigarette filters. It can be spun into fibres and thus used to make an absorbent and safe wound dressing. Shalaby and co-workers used various analytical techniques including scanning electron microscope (SEM) and Fourier-transform infrared (FTIR) spectroscopy to characterise their fibres in which they incorporated silver nanoparticles.

Having characterised the material the team then successfully tested its antibacterial activity against various strains of bacteria that might infect an open wound. They next used the material as a dressing on skin wounds on mice with diabetes and determined how quickly the wound healed with and without the nano dressing. The dressing absorbs fluids exuded by the wound, but also protects the wound from infectious agents while being permeable to air and moisture, the team reports. The use of this dressing also promotes collagen production as the wound heals, which helps to recreate normal skin strength and texture something that is lacking in unassisted wound healing in diabetes mellitus.

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

Preparation and characterisation of antibacterial silver-containing nanofibres for wound healing in diabetic mice by Thanaa Ibrahim Shalaby; Nivan Mahmoud Fekry; Amal Sobhy El Sodfy; Amel Gaber El Sheredy; Maisa El Sayed Sayed Ahmed Moustafa. International Journal of Nanoparticles (IJNP), Vol. 8, No. 1, p. 82 2015 DOI: 10.1504/IJNP.2015.070346

This paper is behind a paywall although there are some exceptions.