Monthly Archives: April 2017

Nanozymes as an antidote for pesticides

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

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

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

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

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

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

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

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

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

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

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

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

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

This paper is behind a paywall.

Nanotechnology and Pakistan

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I don’t often get information about nanotechnology in Pakistan so this March 6, 2017 news article by Mrya Imran on the TheNews.com website provides some welcome insight,

Pakistan has the right level of expert human resource and scientific activity in the field of nanotechnology. A focused national strategy and sustainable funding can make Pakistan one of the leaders in this sector.

These views were expressed by Professor of Physics in University of Illinois and Founder and President of NanoSi Advanced Technology, Inc. Dr Munir H. Nayfeh.  Dr Nayfeh, along with Executive Director, Centre for Nanoscale Science and Technology, and Research Faculty, Department of Agricultural and Biological Engineering, University of Illinois, Dr. Irfan Ahmad and Associate Professor and Director of Medical Physics Programme, Pritzker School of Medicine, University of Chicago, Dr. Bulent Aydogan were invited by COMSATS Institute of Information Technology (CIIT) to deliver lectures on nanotechnology research and entrepreneurship with special focus on cancer nanomedicine.

The objective of the visit was to motivate and mentor faculty and students at COMSATS and also to provide feedback to campus administration and the Federal Ministry of Science and Technology on strategic initiatives to help develop the next generation of science and engineering workforce in Pakistan.

A story of success for the Muslim youth from areas affected by conflict and war, Dr Nayfeh, a Palestinian by origin, was brought up in a conflict area by a mother who did not know how to read and write. For him, the environment was actually a motivator to work hard and study. “My mother was uneducated but she always wanted her children to get the highest degree possible and both my parents supported us in whatever way possible to achieve our dreams,” he recalled.

Comparing Pakistan with other developing countries in scientific research enterprise, he said that despite lack of resources, he has observed some decent amount of research outcome from the existing setups. About their visits to different labs, he said that they found faculty members and researchers in need of for more and more funds. “I don’t blame them as I am also looking for more and more fund even in America. This is a positive sign which shows that these set ups are alive and want to do more.”

…

Dr. Nayfeh is greatly impressed with the number of women researchers and students in Pakistan. “In Tunisia and Algeria, there were decent number of women in this field but Pakistan has the most and there are more publications coming out of Pakistan as compared to other developing countries.”

If you have the time, I suggest you read the article in its entirety.

The Swiss come to a better understanding of nanomaterials

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Just to keep things interesting, after the report suggesting most of the information that the OECD (Organization for Economic Cooperation and Development) has on nanomaterials is of little value for determining risk (see my April 5, 2017 posting for more) the Swiss government has released a report where they claim an improved understanding of nanomaterials than they previously had due to further research into the matter. From an April 6, 2017 news item on Nanowerk,

In the past six years, the [Swiss] National Research Programme “Opportunities and Risks of Nanomaterials” (NRP 64) intensively studied the development, use, behaviour and degradation of engineered nanomaterials, including their impact on humans and on the environment.

Twenty-three research projects on biomedicine, the environment, energy, construction materials and food demonstrated the enormous potential of engineered nanoparticles for numerous applications in industry and medicine. Thanks to these projects we now know a great deal more about the risks associated with nanomaterials and are therefore able to more accurately determine where and how they can be safely used.

An April 6, 2017 Swiss National Science Foundation press release, which originated the news item, expands on the theme,

“One of the specified criteria in the programme was that every project had to examine both the opportunities and the risks, and in some cases this was a major challenge for the researchers,” explains Peter Gehr, President of the NRP 64 Steering Committee.

One development that is nearing industrial application concerns a building material strengthened with nanocellulose that can be used to produce a strong but lightweight insulation material. Successful research was also carried out in the area of energy, where the aim was to find a way to make lithium-ion batteries safer and more efficient.

Promising outlook for nanomedicine

A great deal of potential is predicted for the field of nanomedicine. Nine of the 23 projects in NRP 64 focused on biomedical applications of nanoparticles. These include their use for drug delivery, for example in the fight against viruses, or as immune modulators in a vaccine against asthma. Another promising application concerns the use of nanomagnets for filtering out harmful metallic substances from the blood. One of the projects demonstrated that certain nanoparticles can penetrate the placenta barrier, which points to potential new therapy options. The potential of cartilage and bone substitute materials based on nanocellulose or nanofibres was also studied.

The examination of potential health risks was the focus of NRP 64. A number of projects examined what happens when nanoparticles are inhaled, while two focused on ingestion. One of these investigated whether the human gut is able to absorb iron more efficiently if it is administered in the form of iron nanoparticles in a food additive, while the other studied silicon nanoparticles as they occur in powdered condiments. It was ascertained that further studies will be required in order to determine the doses that can be used without risking an inflammatory reaction in the gut.

What happens to engineered nanomaterials in the environment?

The aim of the seven projects focusing on environmental impact was to gain a better understanding of the toxicity of nanomaterials and their degradability, stability and accumulation in the environment and in biological systems. Here, the research teams monitored how engineered nanoparticles disseminate along their lifecycle, and where they end up or how they can be discarded.

One of the projects established that 95 per cent of silver nanoparticles that are washed out of textiles are collected in sewage treatment plants, while the remaining particles end up in sewage sludge, which in Switzerland is incinerated. In another project a measurement device was developed to determine how aquatic microorganisms react when they come into contact with nanoparticles.

Applying results and making them available to industry

“The findings of the NRP 64 projects form the basis for a safe application of nanomaterials,” says Christoph Studer from the Federal Office of Public Health. “It has become apparent that regulatory instruments such as testing guidelines will have to be adapted at both national and international level.” Studer has been closely monitoring the research programme in his capacity as the Swiss government’s representative in NRP 64. In this context, the precautionary matrix developed by the government is an important instrument by means of which companies can systematically assess the risks associated with the use of nanomaterials in their production processes.

The importance of standardised characterisation and evaluation of engineered nanomaterials was highlighted by the close cooperation among researchers in the programme. “The research network that was built up in the framework of NRP 64 is functioning smoothly and needs to be further nurtured,” says Professor Bernd Nowack from Empa, who headed one of the 23 projects.

The results of NRP 64 show that new key technologies such as the use of nanomaterials need to be closely monitored through basic research due to the lack of data on its long-term effects. As Peter Gehr points out, “We now know a lot more about the risks of nanomaterials and how to keep them under control. However, we need to conduct additional research to learn what happens when humans and the environment are exposed to engineered nanoparticles over longer periods, or what happens a long time after a one-off exposure.”

You can find out more about the Opportunities and Risks of Nanomaterials; National Research Programme (NRP 64) here.

3D printing with cellulose

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The scientists seem quite excited about their work with 3D printing and cellulose. From a March 3, 2017 MIT (Massachusetts Institute of Technology) news release (also on EurekAlert),

For centuries, cellulose has formed the basis of the world’s most abundantly printed-on material: paper. Now, thanks to new research at MIT, it may also become an abundant material to print with — potentially providing a renewable, biodegradable alternative to the polymers currently used in 3-D printing materials.

“Cellulose is the most abundant organic polymer in the world,” says MIT postdoc Sebastian Pattinson, lead author of a paper describing the new system in the journal Advanced Materials Technologies. The paper is co-authored by associate professor of mechanical engineering A. John Hart, the Mitsui Career Development Professor in Contemporary Technology.

Cellulose, Pattinson explains, is “the most important component in giving wood its mechanical properties. And because it’s so inexpensive, it’s biorenewable, biodegradable, and also very chemically versatile, it’s used in a lot of products. Cellulose and its derivatives are used in pharmaceuticals, medical devices, as food additives, building materials, clothing — all sorts of different areas. And a lot of these kinds of products would benefit from the kind of customization that additive manufacturing [3-D printing] enables.”

Meanwhile, 3-D printing technology is rapidly growing. Among other benefits, it “allows you to individually customize each product you make,” Pattinson says.

Using cellulose as a material for additive manufacturing is not a new idea, and many researchers have attempted this but faced major obstacles. When heated, cellulose thermally decomposes before it becomes flowable, partly because of the hydrogen bonds that exist between the cellulose molecules. The intermolecular bonding also makes high-concentration cellulose solutions too viscous to easily extrude.

Instead, the MIT team chose to work with cellulose acetate — a material that is easily made from cellulose and is already widely produced and readily available. Essentially, the number of hydrogen bonds in this material has been reduced by the acetate groups. Cellulose acetate can be dissolved in acetone and extruded through a nozzle. As the acetone quickly evaporates, the cellulose acetate solidifies in place. A subsequent optional treatment replaces the acetate groups and increases the strength of the printed parts.

“After we 3-D print, we restore the hydrogen bonding network through a sodium hydroxide treatment,” Pattinson says. “We find that the strength and toughness of the parts we get … are greater than many commonly used materials” for 3-D printing, including acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA).

To demonstrate the chemical versatility of the production process, Pattinson and Hart added an extra dimension to the innovation. By adding a small amount of antimicrobial dye to the cellulose acetate ink, they 3-D-printed a pair of surgical tweezers with antimicrobial functionality.

“We demonstrated that the parts kill bacteria when you shine fluorescent light on them,” Pattinson says. Such custom-made tools “could be useful for remote medical settings where there’s a need for surgical tools but it’s difficult to deliver new tools as they break, or where there’s a need for customized tools. And with the antimicrobial properties, if the sterility of the operating room is not ideal the antimicrobial function could be essential,” he says.

Because most existing extrusion-based 3-D printers rely on heating polymer to make it flow, their production speed is limited by the amount of heat that can be delivered to the polymer without damaging it. This room-temperature cellulose process, which simply relies on evaporation of the acetone to solidify the part, could potentially be faster, Pattinson says. And various methods could speed it up even further, such as laying down thin ribbons of material to maximize surface area, or blowing hot air over it to speed evaporation. A production system would also seek to recover the evaporated acetone to make the process more cost effective and environmentally friendly.

Cellulose acetate is already widely available as a commodity product. In bulk, the material is comparable in price to that of thermoplastics used for injection molding, and it’s much less expensive than the typical filament materials used for 3-D printing, the researchers say. This, combined with the room-temperature conditions of the process and the ability to functionalize cellulose in a variety of ways, could make it commercially attractive.

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

Additive Manufacturing of Cellulosic Materials with Robust Mechanics and Antimicrobial Functionality by Sebastian W. Pattinson and A. John Hart. Advanced Materials Technologies DOI: 10.1002/admt.201600084 Version of Record online: 30 JAN 2017

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

This paper is behind a paywall.

3D picture language for mathematics

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There’s a new, 3D picture language for mathematics called ‘quon’ according to a March 3, 2017 news item on phys.org,

Galileo called mathematics the “language with which God wrote the universe.” He described a picture-language, and now that language has a new dimension.

The Harvard trio of Arthur Jaffe, the Landon T. Clay Professor of Mathematics and Theoretical Science, postdoctoral fellow Zhengwei Liu, and researcher Alex Wozniakowski has developed a 3-D picture-language for mathematics with potential as a tool across a range of topics, from pure math to physics.

Though not the first pictorial language of mathematics, the new one, called quon, holds promise for being able to transmit not only complex concepts, but also vast amounts of detail in relatively simple images. …

A March 2, 2017 Harvard University news release by Peter Reuell, which originated the news item, provides more context for the research,

“It’s a big deal,” said Jacob Biamonte of the Quantum Complexity Science Initiative after reading the research. “The paper will set a new foundation for a vast topic.”

“This paper is the result of work we’ve been doing for the past year and a half, and we regard this as the start of something new and exciting,” Jaffe said. “It seems to be the tip of an iceberg. We invented our language to solve a problem in quantum information, but we have already found that this language led us to the discovery of new mathematical results in other areas of mathematics. We expect that it will also have interesting applications in physics.”

When it comes to the “language” of mathematics, humans start with the basics — by learning their numbers. As we get older, however, things become more complex.

“We learn to use algebra, and we use letters to represent variables or other values that might be altered,” Liu said. “Now, when we look at research work, we see fewer numbers and more letters and formulas. One of our aims is to replace ‘symbol proof’ by ‘picture proof.’”

The new language relies on images to convey the same information that is found in traditional algebraic equations — and in some cases, even more.

“An image can contain information that is very hard to describe algebraically,” Liu said. “It is very easy to transmit meaning through an image, and easy for people to understand what they see in an image, so we visualize these concepts and instead of words or letters can communicate via pictures.”

“So this pictorial language for mathematics can give you insights and a way of thinking that you don’t see in the usual, algebraic way of approaching mathematics,” Jaffe said. “For centuries there has been a great deal of interaction between mathematics and physics because people were thinking about the same things, but from different points of view. When we put the two subjects together, we found many new insights, and this new language can take that into another dimension.”

In their most recent work, the researchers moved their language into a more literal realm, creating 3-D images that, when manipulated, can trigger mathematical insights.

“Where before we had been working in two dimensions, we now see that it’s valuable to have a language that’s Lego-like, and in three dimensions,” Jaffe said. “By pushing these pictures around, or working with them like an object you can deform, the images can have different mathematical meanings, and in that way we can create equations.”

Among their pictorial feats, Jaffe said, are the complex equations used to describe quantum teleportation. The researchers have pictures for the Pauli matrices, which are fundamental components of quantum information protocols. This shows that the standard protocols are topological, and also leads to discovery of new protocols.

“It turns out one picture is worth 1,000 symbols,” Jaffe said.

“We could describe this algebraically, and it might require an entire page of equations,” Liu added. “But we can do that in one picture, so it can capture a lot of information.”

Having found a fit with quantum information, the researchers are now exploring how their language might also be useful in a number of other subjects in mathematics and physics.

“We don’t want to make claims at this point,” Jaffe said, “but we believe and are thinking about quite a few other areas where this picture-language could be important.”

Sadly, there are no artistic images illustrating quon but this is from the paper,

An n-quon is represented by n hemispheres. We call the flat disc on the boundary of each hemisphere a boundary disc. Each hemisphere contains a neutral diagram with four boundary points on its boundary disk. The dotted box designates the internal structure that specifies the quon vector. For example, the 3-quon is represented as

Courtesy: PNAS and Harvard University

I gather the term ‘quon’ is meant to suggest quantum particles.

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

Quon 3D language for quantum information by Zhengwei Liu, Alex Wozniakowski, and Arthur M. Jaffe. Proceedins of the National Academy of Sciences Published online before print February 6, 2017, doi: 10.1073/pnas.1621345114 PNAS March 7, 2017 vol. 114 no. 10

This paper appears to be open access.

OECD (Organization for Economic Cooperation and Development) Dossiers on Nanomaterials Are of “Little to No Value for assessing risk?”

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The announcement that a significant portion of the OECD’s (Organization for Economic Cooperation and Development) dossiers on 11 nanomaterials have next to no value for assessing risk seems a harsh judgment from the Center for International Environmental Law (CIEL). From a March 1, 2017 posting by Lynn L. Bergeson on the Nanotechnology Now,

On February 23, 2017, the Center for International Environmental Law (CIEL) issued a press release announcing a new report, commissioned by CIEL, the European Environmental Citizens’ Organization for Standardization (ECOS), and the Oeko-Institute, that “shows that most of the information made available by the Sponsorship Testing Programme of the Organisation for Economic Co-operation and Development (OECD) is of little to no value for the regulatory risk assessment of nanomaterials.”

Here’s more from the Feb. 23, 3017 CIEL press release, which originated the posting,

The study published today [Feb. 23, 2017] was delivered by the Institute of Occupational Medicine (IOM) based in Singapore. IOM screened the 11,500 pages of raw data of the OECD dossiers on 11 nanomaterials, and analysed all characterisation and toxicity data on three specific nanomaterials – fullerenes, single-walled carbon nanotubes, and zinc oxide.

“EU policy makers and industry are using the existence of the data to dispel concerns about the potential health and environmental risks of manufactured nanomaterials,” said David Azoulay, Senior Attorney for CIEL. “When you analyse the data, in most cases, it is impossible to assess what material was actually tested. The fact that data exists about a nanomaterial does not mean that the information is reliable to assess the hazards or risks of the material.”

The dossiers were published in 2015 by the OECD’s Working Party on Manufactured Nanomaterials (WPMN), which has yet to draw conclusions on the data quality. Despite this missing analysis, some stakeholders participating in EU policy-making – notably the European Chemicals Agency (ECHA) and the European Commission’s Joint Research Centre – have presented the dossiers as containing information on nano-specific human health and environmental impacts. Industry federations and individual companies have taken this a step further emphasizing that there is enough information available to discard most concerns about potential health or environmental risks of manufactured nanomaterials.

“Our study shows these claims that there is sufficient data available on nanomaterials are not only false, but dangerously so,” said Doreen Fedrigo, Senior Policy Officer of ECOS. ”The lack of nano-specific information in the dossiers means that the results of the tests cannot be used as evidence of no ‘nano-effect’ of the tested material. This information is crucial for regulators and producers who need to know the hazard profile of these materials. Analysing the dossiers has shown that legislation detailing nano-specific information requirements is crucial for the regulatory risk assessment of nanomaterials.”

The report provides important recommendations on future steps in the governance of nanomaterials. “Based on our analysis, serious gaps in current dossiers must be filled in with characterisation information, preparation protocols, and exposure data,” said Andreas Hermann of the Oeko-Institute. “Using these dossiers as they are and ignoring these recommendations would mean making decisions on the safety of nanomaterials based on faulty and incomplete data. Our health and environment requires more from producers and regulators.”

CIEL has an Analysis of OECD WPMN Dossiers Regarding the Availability of Data to Evaluate and Regulate Risk (Dec 2016) webpage which provides more information about the dossiers and about the research into the dossiers and includes links to the report, the executive summer, and the dataset,

The Sponsorship Testing Programme of the Working Party on Manufactured Nanomaterials (WPMN) of the Organisation for Economic Co-operation and Development (OECD) started in 2007 with the aim to test a selection of 13 representative nanomaterials for many endpoints. The main objectives of the programme were to better understand what information on intrinsic properties of the nanomaterials might be relevant for exposure and hazards assessment and assess the validity of OECD chemicals Test Guidelines for nanomaterials. The testing programme concluded in 2015 with the publication of dossiers on 11 nanomaterials: 11,500 pages of raw data to be analysed and interpreted.

The WPMN has not drawn conclusions on the data quality, but some stakeholders participating in EU policy-making – notably the European Chemicals Agency and the European Commission’s Joint Research Centre – presented the dossiers as containing much scientific information that provided a better understanding of their nano-specific human health and environmental impacts. Industry federations and individual companies echoed the views, highlighting that there was enough information available to discard most concerns about potential health or environmental risks of manufactured nanomaterials.

As for the OECD, it concluded, even before the publication of the dossiers, that “many of the existing guidelines are also suitable for the safety assessment of nanomaterials” and “the outcomes (of the sponsorship programme) will provide useful information on the ‘intrinsic properties’ of nanomaterials.”

The Center for International Environmental Law (CIEL), the European Citizens’ Organisation for Standardisation (ECOS) and the Öko-Institut commissioned scientific analysis of these dossiers to assess the relevance of the data for regulatory risk assessment.

The resulting report: Analysis of OECD WPMN dossiers regarding the availability of data to evaluate and regulate risk, provides insights illustratating how most of the information made available by the sponsorship programme is of little to no value in identifying hazards or in assessing risks due to nanomaterials.

The analysis shows that:

  • Most studies and documents in the dossiers contain insufficient characterisation data about the specific nanomaterial addressed (size, particle distribution, surface shape, etc.), making it impossible to assess what material was actually tested.
  • This makes it impossible to make any firm statements regarding the nano-specificity of the hazard data published, or the relationship between observed effects and specific nano-scale properties.
  • Less than 2% of the study records provide detail on the size of the nanomaterial tested. Most studies use mass rather than number or size distribution (so not following scientifically recommended reporting practice).
  • The absence of details on the method used to prepare the nanomaterial makes it virtually impossible to correlate an identified hazard with specific nanomaterial characteristic. Since the studies do not indicate dispersion protocols used, it is impossible to assess whether the final dispersion contained the intended mass concentration (or even the actual presence of nanomaterials in the test system), how much agglomeration may have occurred, and how the preparation protocols may have influenced the size distribution.
  • There is not enough nano-specific information in the dossiers to inform about nano-characteristics of the raw material that influence their toxicology. This information is important for regulators and its absence makes information in the dossier irrelevant to develop read-across guidelines.
  • Only about half of the endpoint study records using OECD Test Guideliness (TGs) were delivered using unaltered OECD TGs, thereby respecting the Guidelines’ requirements. The reasons for modifications of the TGs used in the tests are not clear from the documentation. This includes whether the study record was modified to account for challenges related to specific nanomaterial properties or for other, non-nano-specific reasons.
  • The studies do not contain systematic testing of the influence of nano-specific characteristics on the study outcome, and they do not provide the data needed to assess the effect of nano-scale features on the Test Guidelines. Given the absence of fundamental information on nanomaterial characteristics, the dossiers do not provide evidence of the applicability of existing OECD Test Guidelines to nanomaterials.

The analysis therefore dispels several myths created by some stakeholders following publication of the dossiers and provides important perspective for the governance of nanomaterials. In particular, the analysis makes recommendations to:

  • Systematically assess the validity of existing Test Guidelines for relevance to nanomaterials
  • Develop Test Guidelines for dispersion and other test preparations
  • Define the minimum characteristics of nanomaterials that need to be reported
  • Support the build-up of exposure database
  • Fill the gaps in current dossiers with characterisation information, preparation protocols and exposure data

Read full report.
Read executive summary.
Download full dataset.

This is not my area of expertise and while I find the language a bit inflammatory, it’s my understanding that there are great gaps in our understanding of nanomaterials and testing for risk assessment has been criticized for many of the reasons pointed out by CIEL, ECOS, and the Oeko-Institute.

You can find out more about CIEL here; ECOS here; and the Oeko-Institute (also known as Öko-Institute) here.

Portable nanofibre fabrication device (point-of-use manufacturing)

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A portable nanofiber fabrication device is quite an achievement although it seems it’s not quite ready for prime time yet. From a March 1, 2017 news item on Nanowerk (Note: A link has been removed),

Harvard researchers have developed a lightweight, portable nanofiber fabrication device that could one day be used to dress wounds on a battlefield or dress shoppers in customizable fabrics. The research was published recently in Macromolecular Materials and Engineering (“Design and Fabrication of Fibrous Nanomaterials Using Pull Spinning”)

A schematic of the pull spinning apparatus with a side view illustration of a fiber being pulled from the polymer reservoir. The pull spinning system consists of a rotating bristle that dips and pulls a polymer jet in a spiral trajectory (Leila Deravi/Harvard University)

A March 1, 2017 Harvard University news release (also on EurekAlert) by Leah Burrow,, which originated the news item, describes the current process for nanofiber fabrication and explains how this technique is an improvement,

There are many ways to make nanofibers. These versatile materials — whose target applications include everything from tissue engineering to bullet proof vests — have been made using centrifugal force, capillary force, electric field, stretching, blowing, melting, and evaporation.

Each of these fabrication methods has pros and cons. For example, Rotary Jet-Spinning (RJS) and Immersion Rotary Jet-Spinning (iRJS) are novel manufacturing techniques developed in the Disease Biophysics Group at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering. Both RJS and iRJS dissolve polymers and proteins in a liquid solution and use centrifugal force or precipitation to elongate and solidify polymer jets into nanoscale fibers. These methods are great for producing large amounts of a range of materials – including DNA, nylon, and even Kevlar – but until now they haven’t been particularly portable.

The Disease Biophysics Group recently announced the development of a hand-held device that can quickly produce nanofibers with precise control over fiber orientation. Regulating fiber alignment and deposition is crucial when building nanofiber scaffolds that mimic highly aligned tissue in the body or designing point-of-use garments that fit a specific shape.

“Our main goal for this research was to make a portable machine that you could use to achieve controllable deposition of nanofibers,” said Nina Sinatra, a graduate student in the Disease Biophysics Group and co-first author of the paper. “In order to develop this kind of point-and-shoot device, we needed a technique that could produce highly aligned fibers with a reasonably high throughput.”

The new fabrication method, called pull spinning, uses a high-speed rotating bristle that dips into a polymer or protein reservoir and pulls a droplet from solution into a jet. The fiber travels in a spiral trajectory and solidifies before detaching from the bristle and moving toward a collector. Unlike other processes, which involve multiple manufacturing variables, pull spinning requires only one processing parameter — solution viscosity — to regulate nanofiber diameter. Minimal process parameters translate to ease of use and flexibility at the bench and, one day, in the field.

Pull spinning works with a range of different polymers and proteins. The researchers demonstrated proof-of-concept applications using polycaprolactone and gelatin fibers to direct muscle tissue growth and function on bioscaffolds, and nylon and polyurethane fibers for point-of-wear apparel.

“This simple, proof-of-concept study demonstrates the utility of this system for point-of-use manufacturing,” said Kit Parker, the Tarr Family Professor of Bioengineering and Applied Physics and director of the Disease Biophysics Group. “Future applications for directed production of customizable nanotextiles could extend to spray-on sportswear that gradually heats or cools an athlete’s body, sterile bandages deposited directly onto a wound, and fabrics with locally varying mechanical properties.”

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

Design and Fabrication of Fibrous Nanomaterials Using Pull Spinning by Leila F. Deravi, Nina R. Sinatra, Christophe O. Chantre, Alexander P. Nesmith, Hongyan Yuan, Sahm K. Deravi, Josue A. Goss, Luke A. MacQueen, Mohammad R. Badrossamy, Grant M. Gonzalez, Michael D. Phillips, and Kevin Kit Parker. Macromolecular Materials and Engineering DOI: 10.1002/mame.201600404 Version of Record online: 17 JAN 2017

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

This paper is behind a paywall.

‘No kiln’ ceramics

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Sometimes it’s hard to believe what one reads and this piece about ceramics made without kilns  (for me) fits into that category (from a Feb. 28, 2017 ETH Zurich [English: Swiss Federal Institute of Technology in Zurich] [German: Eidgenössische Technische Hochschule Zürich]) press release (also on EurekAlert) by Fabio Bergamin),

The manufacture of cement, bricks, bathroom tiles and porcelain crockery normally requires a great deal of heat: a kiln is used to fire the ceramic materials at temperatures well in excess of 1,000°C. Now, material scientists from ETH Zurich have developed what seems at first glance to be an astonishingly simple method of manufacture that works at room temperature. The scientists used a calcium carbonate nanopowder as the starting material and instead of firing it, they added a small amount of water and then compacted it.

“The manufacturing process is based on the geological process of rock formation,” explains Florian Bouville, a postdoc in the group of André Studart, Professor of Complex Materials. Sedimentary rock is formed from sediment that is compressed over millions of years through the pressure exerted by overlying deposits. This process turns calcium carbonate sediment into limestone with the help of the surrounding water. As the ETH researchers used calcium carbonate with an extremely fine particle size (nanoparticles) as the starting material, their compacting process took only an hour. “Our work is the first evidence that a piece of ceramic material can be manufactured at room temperature in such a short amount of time and with relatively low pressures,” says ETH professor Studart.

Stronger than concrete

As tests have shown, the new material can withstand about ten times as much force as concrete before it breaks, and is as stiff as stone or concrete. In other words, it is just as hard to deform.

So far, the scientists have produced material samples of about the size of a one-franc piece using a conventional hydraulic press such as those normally used in industry. “The challenge is to generate a sufficiently high pressure for the compacting process. Larger workpieces require a correspondingly greater force,” says Bouville. According to the scientists, ceramic pieces the size of small bathroom tiles should theoretically be feasible.

Energy-efficient and environmentally benign

“For a long time, material scientists have been searching for a way to produce ceramic materials under mild conditions, as the firing process requires a large amount of energy,” says Studart. The new room-temperature method – which experts refer to as cold sintering — is much more energy-efficient and also enables the production of composite materials containing, for example, plastic.

The technique is also of interest with a view to a future CO2-neutral society. Specifically, the carbonate nanoparticles could conceivably be produced using CO2 captured from the atmosphere or from waste gases from thermal power stations. In this scenario, the captured CO2 is allowed to react with a suitable rock in powder form to produce carbonate, which could then be used to manufacture ceramics at room temperature. The climate-damaging CO2 would thus be stored in ceramic products in the long term. These would constitute a CO2 sink and could help thermal power stations to operate on a carbon-neutral basis.

According to the scientists, in the long term, the new approach of cold sintering even has the potential to lead to more environmentally friendly substitutes for cement-based materials. However, great research efforts are needed to reach this goal. Cement production is not only energy-intensive, but it also generates large amounts of CO2 – unlike potential cold-sintered replacement materials.

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

Geologically-inspired strong bulk ceramics made with water at room temperature by Florian Bouville & André R. Studart. Nature Communications 8, Article number: 14655 (2017) doi:10.1038/ncomms14655 Published online: 06 March 2017

This paper is open access.

Florian Bouville’s work in ceramics was last mentioned here in a March 25, 2014 posting.

Revolutionizing electronics with liquid metal technology?

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I’m not sure I’d call it the next big advance in electronics, there are too many advances jockeying for that position but this work from Australia and the US is fascinating. From a Feb. 17, 2017 news item on ScienceDaily,

A new technique using liquid metals to create integrated circuits that are just atoms thick could lead to the next big advance for electronics.

The process opens the way for the production of large wafers around 1.5 nanometres in depth (a sheet of paper, by comparison, is 100,000nm thick).

Other techniques have proven unreliable in terms of quality, difficult to scale up and function only at very high temperatures — 550 degrees or more.

A Feb. 17, 2017 RMIT University press release (also on EurekAlert), which originated the news item, expands on the theme (Note: A link has been removed),

Distinguished Professor Kourosh Kalantar-zadeh, from RMIT’s School of Engineering, led the project, which also included colleagues from RMIT and researchers from CSIRO, Monash University, North Carolina State University and the University of California.

He said the electronics industry had hit a barrier.

“The fundamental technology of car engines has not progressed since 1920 and now the same is happening to electronics. Mobile phones and computers are no more powerful than five years ago.

“That is why this new 2D printing technique is so important – creating many layers of incredibly thin electronic chips on the same surface dramatically increases processing power and reduces costs.

“It will allow for the next revolution in electronics.”

Benjamin Carey, a researcher with RMIT and the CSIRO, said creating electronic wafers just atoms thick could overcome the limitations of current chip production.

It could also produce materials that were extremely bendable, paving the way for flexible electronics.

“However, none of the current technologies are able to create homogenous surfaces of atomically thin semiconductors on large surface areas that are useful for the industrial scale fabrication of chips.

“Our solution is to use the metals gallium and indium, which have a low melting point.

“These metals produce an atomically thin layer of oxide on their surface that naturally protects them. It is this thin oxide which we use in our fabrication method.

“By rolling the liquid metal, the oxide layer can be transferred on to an electronic wafer, which is then sulphurised. The surface of the wafer can be pre-treated to form individual transistors.

“We have used this novel method to create transistors and photo-detectors of very high gain and very high fabrication reliability in large scale.”

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

Wafer-scale two-dimensional semiconductors from printed oxide skin of liquid metals by Benjamin J. Carey, Jian Zhen Ou, Rhiannon M. Clark, Kyle J. Berean, Ali Zavabeti, Anthony S. R. Chesman, Salvy P. Russo, Desmond W. M. Lau, Zai-Quan Xu, Qiaoliang Bao, Omid Kevehei, Brant C. Gibson, Michael D. Dickey, Richard B. Kaner, Torben Daeneke, & Kourosh Kalantar-Zadeh. Nature Communications 8, Article number: 14482 (2017) doi:10.1038/ncomms14482
Published online: 17 February 2017

This paper is open access.