Category Archives: health and safety

US Dept. of Agriculture announces its nanotechnology research grants

I don’t always stumble across the US Department of Agriculture’s nanotechnology research grant announcements but I’m always grateful when I do as it’s good to find out about  nanotechnology research taking place in the agricultural sector. From a July 21, 2017 news item on Nanowerk,,

The U.S. Department of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA) today announced 13 grants totaling $4.6 million for research on the next generation of agricultural technologies and systems to meet the growing demand for food, fuel, and fiber. The grants are funded through NIFA’s Agriculture and Food Research Initiative (AFRI), authorized by the 2014 Farm Bill.

“Nanotechnology is being rapidly implemented in medicine, electronics, energy, and biotechnology, and it has huge potential to enhance the agricultural sector,” said NIFA Director Sonny Ramaswamy. “NIFA research investments can help spur nanotechnology-based improvements to ensure global nutritional security and prosperity in rural communities.”

A July 20, 2017 USDA news release, which originated the news item, lists this year’s grants and provides a brief description of a few of the newly and previously funded projects,

Fiscal year 2016 grants being announced include:

Nanotechnology for Agricultural and Food Systems

  • Kansas State University, Manhattan, Kansas, $450,200
  • Wichita State University, Wichita, Kansas, $340,000
  • University of Massachusetts, Amherst, Massachusetts, $444,550
  • University of Nevada, Las Vegas, Nevada,$150,000
  • North Dakota State University, Fargo, North Dakota, $149,000
  • Cornell University, Ithaca, New York, $455,000
  • Cornell University, Ithaca, New York, $450,200
  • Oregon State University, Corvallis, Oregon, $402,550
  • University of Pennsylvania, Philadelphia, Pennsylvania, $405,055
  • Gordon Research Conferences, West Kingston, Rhode Island, $45,000
  • The University of Tennessee,  Knoxville, Tennessee, $450,200
  • Utah State University, Logan, Utah, $450,200
  • The George Washington University, Washington, D.C., $450,200

Project details can be found at the NIFA website (link is external).

Among the grants, a University of Pennsylvania project will engineer cellulose nanomaterials [emphasis mine] with high toughness for potential use in building materials, automotive components, and consumer products. A University of Nevada-Las Vegas project will develop a rapid, sensitive test to detect Salmonella typhimurium to enhance food supply safety.

Previously funded grants include an Iowa State University project in which a low-cost and disposable biosensor made out of nanoparticle graphene that can detect pesticides in soil was developed. The biosensor also has the potential for use in the biomedical, environmental, and food safety fields. University of Minnesota (link is external) researchers created a sponge that uses nanotechnology to quickly absorb mercury, as well as bacterial and fungal microbes from polluted water. The sponge can be used on tap water, industrial wastewater, and in lakes. It converts contaminants into nontoxic waste that can be disposed in a landfill.

NIFA invests in and advances agricultural research, education, and extension and promotes transformative discoveries that solve societal challenges. NIFA support for the best and brightest scientists and extension personnel has resulted in user-inspired, groundbreaking discoveries that combat childhood obesity, improve and sustain rural economic growth, address water availability issues, increase food production, find new sources of energy, mitigate climate variability and ensure food safety. To learn more about NIFA’s impact on agricultural science, visit www.nifa.usda.gov/impacts, sign up for email updates (link is external) or follow us on Twitter @USDA_NIFA (link is external), #NIFAImpacts (link is external).

Given my interest in nanocellulose materials (Canada was/is a leader in the production of cellulose nanocrystals [CNC] but there has been little news about Canadian research into CNC applications), I used the NIFA link to access the table listing the grants and clicked on ‘brief’ in the View column in the University of Pennsylania row to find this description of the project,

ENGINEERING CELLULOSE NANOMATERIALS WITH HIGH TOUGHNESS

NON-TECHNICAL SUMMARY: Cellulose nanofibrils (CNFs) are natural materials with exceptional mechanical properties that can be obtained from renewable plant-based resources. CNFs are stiff, strong, and lightweight, thus they are ideal for use in structural materials. In particular, there is a significant opportunity to use CNFs to realize polymer composites with improved toughness and resistance to fracture. The overall goal of this project is to establish an understanding of fracture toughness enhancement in polymer composites reinforced with CNFs. A key outcome of this work will be process – structure – fracture property relationships for CNF-reinforced composites. The knowledge developed in this project will enable a new class of tough CNF-reinforced composite materials with applications in areas such as building materials, automotive components, and consumer products.The composite materials that will be investigated are at the convergence of nanotechnology and bio-sourced material trends. Emerging nanocellulose technologies have the potential to move biomass materials into high value-added applications and entirely new markets.

It’s not the only nanocellulose material project being funded in this round, there’s this at North Dakota State University, from the NIFA ‘brief’ project description page,

NOVEL NANOCELLULOSE BASED FIRE RETARDANT FOR POLYMER COMPOSITES

NON-TECHNICAL SUMMARY: Synthetic polymers are quite vulnerable to fire.There are 2.4 million reported fires, resulting in 7.8 billion dollars of direct property loss, an estimated 30 billion dollars of indirect loss, 29,000 civilian injuries, 101,000 firefighter injuries and 6000 civilian fatalities annually in the U.S. There is an urgent need for a safe, potent, and reliable fire retardant (FR) system that can be used in commodity polymers to reduce their flammability and protect lives and properties. The goal of this project is to develop a novel, safe and biobased FR system using agricultural and woody biomass. The project is divided into three major tasks. The first is to manufacture zinc oxide (ZnO) coated cellulose nanoparticles and evaluate their morphological, chemical, structural and thermal characteristics. The second task will be to design and manufacture polymer composites containing nano sized zinc oxide and cellulose crystals. Finally the third task will be to test the fire retardancy and mechanical properties of the composites. Wbelieve that presence of zinc oxide and cellulose nanocrystals in polymers will limit the oxygen supply by charring, shielding the surface and cellulose nanocrystals will make composites strong. The outcome of this project will help in developing a safe, reliable and biobased fire retardant for consumer goods, automotive, building products and will help in saving human lives and property damage due to fire.

One day, I hope to hear about Canadian research into applications for nanocellulose materials. (fingers crossed for good luck)

DISCmini: world’s smallest handheld nanoparticle counter

DISCmini: a handheld diffusion size classifier for nanoparticle measurement Courtesy: Testo

They’/re claiming this is the world’s smallest in a July 12, 2017 news item on Nanowerk,

Testo, Inc., the world’s leading manufacturer of test and measurement instruments, announces the DiSCmini, the smallest handheld instrument for the measurement of nanoparticle. DiSCmini measures: particle number, average particle diameter and lung-deposited surface area (LDSA) with time resolution and logging at 1 second (1 Hz).

Testo’s DISCmini product page offers a video and more details,

Negative health effects due to nanoparticles appear to correlate particularly well with number concentration or surface. Epidemiological and toxicological studies are still mainly based on total mass, or they use fuzzy proxies like “distance from a busy road” to describe personal exposure, although the health-related effects of particle number concentration are well known. We believe that this contradictory situation is due to the lack of adequate sensors on the market.

This gap is now closed with Testo Particle´s handheld version of the “Diffusion Size Classifier”, testo DiSCmini.  The testo DiSCmini is a portable sensor for the measurement of particle number and average diameter with a time resolution of up to 1 second (1 Hz). The simultaneous capture of number concentration and particle size allows the specification of other characteristic parameters, such as the particles surface (Lung Deposited Surface Area, LDSA). The instrument is battery powered with a lifetime of up to 8 hours; data can be recorded on a memory card, and transferred to a external computer via USB cable.

The testo DiSCmini is particularly efficient for personal exposure monitoring in particle-loaded work space with toxic air contaminants such as diesel soot, welding fumes, or industrial nanomaterials.

The testo DiSCmini is based on the electrical charging of the aerosols. Positive air ions generated in a corona discharge are mixed with the aerosol. The charged particles are then detected in two stages by electrometers. The first detector stage is a pile of steel grids; small particles will preferably deposit on it by diffusion. The second stage is a high-efficiency particle filter which captures all the other particles. The mean particle size can be obtained by analysis of the two currents measured on the stages. The particle count is determined with the total current. The testo DiSCmini detects particles ranging in size from 10 to about 700 nm, while the modal value should lie below 300 nm. The concentration range is from about 1’000 to over 1’000’000 particles per cubic centimetre. The accuracy of the measurement depends on the shape of the particle size distribution and number concentration, and is usually around 15-20% compared to a reference CPC. The unit should be serviced and calibrated once a year.

Unlike other instruments the testo DiSCmini needs neither working liquid of any kind nor radioactive sources. Therefore, it can be operated in any position and over extended periods without requiring a liquid refill. Typical applications include the determination of personal exposure in particle-loaded jobs (diesel soot, welding fumes, industrial nanomaterials) or in vulnerable groups (asthmatics, COPD patients). The development of large area survey grids of ambient air is becoming possible. The small size of  the testo DiSCmini makes the instrument particularly suitable for personal carry-on measurement campaigns. The high measurement frequency of 1 Hz allows the instrument to monitor rapid changes in the aerosol. This feature is particularly interesting to local or defined sources of particle generation. The equipment is designed for situations and applications where quick and easy access to particle number concentration and average diameter is desired.

For anyone interested in the technical specifications, there’s the DISCmini product brochure.

Nano with green tea for sensitive teeth

The future will be beautiful if scientists are successful with a new DNA (deoxyribonucleic acid) sunscreen (my Aug. 3, 2017 posting) and a new dental material for people with sensitive teeth. From an Aug. 2, 2017 news item on phys.org,

An ice cold drink is refreshing in the summer, but for people with sensitive teeth, it can cause a painful jolt in the mouth. This condition can be treated, but many current approaches don’t last long. Now researchers report in the journal ACS [American Chemical Society] Applied Materials & Interfaces the development of a new material with an extract from green tea that could fix this problem—and help prevent cavities in these susceptible patients.

An Aug. 2, 2017 ACS news release, which originated the news item, describes the problem and the work in more detail,

Tooth sensitivity commonly occurs when the protective layers of teeth are worn away, revealing a bony tissue called dentin. This tissue contains microscopic hollow tubes that, when exposed, allow hot and cold liquids and food to contact the underlying nerve endings in the teeth, causing pain. Unprotected dentin is also vulnerable to cavity formation. Plugging these tubes with a mineral called nanohydroxyapatite is a long-standing approach to treating sensitivity. But the material doesn’t stand up well to regular brushing, grinding, erosion or acid produced by cavity-causing bacteria. Cui Huang and colleagues wanted to tackle sensitivity and beat the bacteria at the same time.

The researchers encapsulated nanohydroxyapatite and a green tea polyphenol — epigallocatechin-3-gallate, or EGCG — in silica nanoparticles, which can stand up to acid and wear and tear. EGCG has been shown in previous studies to fight Streptococcus mutans, which forms biofilms that cause cavities. Testing on extracted wisdom teeth showed that the material plugged the dentin tubules, released EGCG for at least 96 hours, stood up to tooth erosion and brushing and prevented biofilm formation. It also showed low toxicity. Based on these findings, the researchers say the material could indeed be a good candidate for combating tooth sensitivity and cavities.

The authors acknowledge funding from the National Natural Science Foundation of China, the Natural Science Foundation of Hubei Province of China and the Fundamental Research Funds for the Central Universities.

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

Development of Epigallocatechin-3-gallate-Encapsulated Nanohydroxyapatite/Mesoporous Silica for Therapeutic Management of Dentin Surface by Jian Yu, Hongye Yang, Kang Li, Hongyu Ren, Jinmei Lei, and Cui Huang. ACS Appl. Mater. Interfaces, Article ASAP DOI: 10.1021/acsami.7b06597 Publication Date (Web): July 13, 2017

Copyright © 2017 American Chemical Society

This paper is behind a paywall.

DNA sunscreen: the longer you wear it, the better it gets due to its sacrificial skin

Using this new sunscreen does mean slathering on salmon sperm, more or lees, (read the Methods section of the academic paper cited later in this post). Considering that you’ve likely eaten (insect parts in chocolate) and slathered on more discomfiting stuff already and this development gives you access to an all natural, highly effective sunscreen, if it ever makes its way out of the laboratory, it might not be so bad. From a July 26, 2017 article by Sarah Knapton for The Telegraph,

Sunscreen made from DNA [deoxyribonucleic acid] which acts like a second skin to prevent sun damage is on the horizon.

Scientists in the US have developed a film from the DNA of salmon which gets better at protecting the skin from ultraviolet light the more it is exposed to the Sun.

It also helps lock in moisture beneath the surface which is usually lost during tanning.

Exciting, yes? A July 27, 2017 Binghamton University news release (also on EurekAlert but dated July 26, 2017) provides more detail,

“Ultraviolet (UV) light can actually damage DNA, and that’s not good for the skin,” said Guy German, assistant professor of biomedical engineering at Binghamton University. “We thought, let’s flip it. What happens instead if we actually used DNA as a sacrificial layer? So instead of damaging DNA within the skin, we damage a layer on top of the skin.”

German and a team of researchers developed thin and optically transparent crystalline DNA films and irradiated them with UV light. They found that the more they exposed the film to UV light, the better the film got at absorbing it.

“If you translate that, it means to me that if you use this as a topical cream or sunscreen, the longer that you stay out on the beach, the better it gets at being a sunscreen,” said German.

As an added bonus, the DNA coatings are also hygroscopic, meaning that skin coated with the DNA films can store and hold water much more than uncoated skin. When applied to human skin, they are capable of slowing water evaporation and keeping the tissue hydrated for extended periods of time.

German intends to see next if these materials might be good as a wound covering for hostile environments where 1) you want to be able to see the wound healing without removing the dressing, 2) you want to protect the wound from the sun and 3) you want to keep the wound in a moist environment, known to promote faster wound healing rates.

“Not only do we think this might have applications for sunscreen and moisturizers directly, but if it’s optically transparent and prevents tissue damage from the sun and it’s good at keeping the skin hydrated, we think this might be potentially exploitable as a wound covering for extreme environments,” he said.

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

Non-ionising UV light increases the optical density of hygroscopic self assembled DNA crystal films by Alexandria E. Gasperini, Susy Sanchez, Amber L. Doiron, Mark Lyles & Guy K. German. Scientific Reports 7, Article number: 6631 (2017) doi:10.1038/s41598-017-06884-8 Published online: 26 July 2017

This paper is open access.

Meet Pepper, a robot for health care clinical settings

A Canadian project to introduce robots like Pepper into clinical settings (aside: can seniors’ facilities be far behind?) is the subject of a June 23, 2017 news item on phys.org,

McMaster and Ryerson universities today announced the Smart Robots for Health Communication project, a joint research initiative designed to introduce social robotics and artificial intelligence into clinical health care.

A June 22, 2017 McMaster University news release, which originated the news item, provides more detail,

With the help of Softbank’s humanoid robot Pepper and IBM Bluemix Watson Cognitive Services, the researchers will study health information exchange through a state-of-the-art human-robot interaction system. The project is a collaboration between David Harris Smith, professor in the Department of Communication Studies and Multimedia at McMaster University, Frauke Zeller, professor in the School of Professional Communication at Ryerson University and Hermenio Lima, a dermatologist and professor of medicine at McMaster’s Michael G. DeGroote School of Medicine. His main research interests are in the area of immunodermatology and technology applied to human health.

The research project involves the development and analysis of physical and virtual human-robot interactions, and has the capability to improve healthcare outcomes by helping healthcare professionals better understand patients’ behaviour.

Zeller and Harris Smith have previously worked together on hitchBOT, the friendly hitchhiking robot that travelled across Canada and has since found its new home in the [Canada] Science and Technology Museum in Ottawa.

“Pepper will help us highlight some very important aspects and motives of human behaviour and communication,” said Zeller.

Designed to be used in professional environments, Pepper is a humanoid robot that can interact with people, ‘read’ emotions, learn, move and adapt to its environment, and even recharge on its own. Pepper is able to perform facial recognition and develop individualized relationships when it interacts with people.

Lima, the clinic director, said: “We are excited to have the opportunity to potentially transform patient engagement in a clinical setting, and ultimately improve healthcare outcomes by adapting to clients’ communications needs.”

At Ryerson, Pepper was funded by the Co-lab in the Faculty of Communication and Design. FCAD’s Co-lab provides strategic leadership, technological support and acquisitions of technologies that are shaping the future of communications.

“This partnership is a testament to the collaborative nature of innovation,” said dean of FCAD, Charles Falzon. “I’m thrilled to support this multidisciplinary project that pushes the boundaries of research, and allows our faculty and students to find uses for emerging tech inside and outside the classroom.”

“This project exemplifies the value that research in the Humanities can bring to the wider world, in this case building understanding and enhancing communications in critical settings such as health care,” says McMaster’s Dean of Humanities, Ken Cruikshank.

The integration of IBM Watson cognitive computing services with the state-of-the-art social robot Pepper, offers a rich source of research potential for the projects at Ryerson and McMaster. This integration is also supported by IBM Canada and [Southern Ontario Smart Computing Innovation Platform] SOSCIP by providing the project access to high performance research computing resources and staff in Ontario.

“We see this as the initiation of an ongoing collaborative university and industry research program to develop and test applications of embodied AI, a research program that is well-positioned to integrate and apply emerging improvements in machine learning and social robotics innovations,” said Harris Smith.

I just went to a presentation at the facility where my mother lives and it was all about delivering more individualized and better care for residents. Given that most seniors in British Columbia care facilities do not receive the number of service hours per resident recommended by the province due to funding issues, it seemed a well-meaning initiative offered in the face of daunting odds against success. Now with this news, I wonder what impact ‘Pepper’ might ultimately have on seniors and on the people who currently deliver service. Of course, this assumes that researchers will be able to tackle problems with understanding various accents and communication strategies, which are strongly influenced by culture and, over time, the aging process.

After writing that last paragraph I stumbled onto this June 27, 2017 Sage Publications press release on EurekAlert about a related matter,

Existing digital technologies must be exploited to enable a paradigm shift in current healthcare delivery which focuses on tests, treatments and targets rather than the therapeutic benefits of empathy. Writing in the Journal of the Royal Society of Medicine, Dr Jeremy Howick and Dr Sian Rees of the Oxford Empathy Programme, say a new paradigm of empathy-based medicine is needed to improve patient outcomes, reduce practitioner burnout and save money.

Empathy-based medicine, they write, re-establishes relationship as the heart of healthcare. “Time pressure, conflicting priorities and bureaucracy can make practitioners less likely to express empathy. By re-establishing the clinical encounter as the heart of healthcare, and exploiting available technologies, this can change”, said Dr Howick, a Senior Researcher in Oxford University’s Nuffield Department of Primary Care Health Sciences.

Technology is already available that could reduce the burden of practitioner paperwork by gathering basic information prior to consultation, for example via email or a mobile device in the waiting room.

During the consultation, the computer screen could be placed so that both patient and clinician can see it, a help to both if needed, for example, to show infographics on risks and treatment options to aid decision-making and the joint development of a treatment plan.

Dr Howick said: “The spread of alternatives to face-to-face consultations is still in its infancy, as is our understanding of when a machine will do and when a person-to-person relationship is needed.” However, he warned, technology can also get in the way. A computer screen can become a barrier to communication rather than an aid to decision-making. “Patients and carers need to be involved in determining the need for, and designing, new technologies”, he said.

I sincerely hope that the Canadian project has taken into account some of the issues described in the ’empathy’ press release and in the article, which can be found here,

Overthrowing barriers to empathy in healthcare: empathy in the age of the Internet
by J Howick and S Rees. Journaly= of the Royal Society of Medicine Article first published online: June 27, 2017 DOI: https://doi.org/10.1177/0141076817714443

This article is open access.

Nanoparticle behaviour in the environment unpredictable

These Swiss researchers took on a fairly massive project according to an April 19, 2017 news item on ScienceDaily,

The nanotech industry is booming. Every year, several thousands of tonnes of man-made nanoparticles are produced worldwide; sooner or later, a certain part of them will end up in bodies of water or soil. But even experts find it difficult to say exactly what happens to them there. It is a complex question, not only because there are many different types of man-made (engineered) nanoparticles, but also because the particles behave differently in the environment depending on the prevailing conditions.

Researchers led by Martin Scheringer, Senior Scientist at the Department of Chemistry and Applied Biosciences, wanted to bring some clarity to this issue. They reviewed 270 scientific studies, and the nearly 1,000 laboratory experiments described in them, looking for patterns in the behaviour of engineered nanoparticles. The goal was to make universal predictions about the behaviour of the particles.

An April 19, 2017ETH Zurich press release by Fabio Bergamin (also on EurekAlert), which originated the news item, elaborates,

Particles attach themselves to everything

However, the researchers found a very mixed picture when they looked at the data. “The situation is more complex than many scientists would previously have predicted,” says Scheringer. “We need to recognise that we can’t draw a uniform picture with the data available to us today.”

Nicole Sani-Kast, a doctoral student in Scheringer’s group and first author of the analysis published in the journal PNAS [Proceedings of the National Academy of Sciences], adds: “Engineered nanoparticles behave very dynamically and are highly reactive. They attach themselves to everything they find: to other nanoparticles in order to form agglomerates, or to other molecules present in the environment.”

Network analysis

To what exactly the particles react, and how quickly, depends on various factors such as the acidity of the water or soil, the concentration of the existing minerals and salts, and above all, the composition of the organic substances dissolved in the water or present in the soil. The fact that the engineered nanoparticles often have a surface coating makes things even more complicated. Depending on the environmental conditions, the particles retain or lose their coating, which in turn influences their reaction behaviour.

To evaluate the results available in the literature, Sani-Kast used a network analysis for the first time in this research field. It is a technique familiar in social research for measuring networks of social relations, and allowed her to show that the data available on engineered nanoparticles is inconsistent, insufficiently diverse and poorly structured.

More method for machine learning

“If more structured, consistent and sufficiently diverse data were available, it may be possible to discover universal patterns using machine learning methods,” says Scheringer, “but we’re not there yet.” Enough structured experimental data must first be available.

“In order for the scientific community to carry out such experiments in a systematic and standardised manner, some kind of coordination is necessary,” adds Sani-Kast, but she is aware that such work is difficult to coordinate. Scientists are generally well known for preferring to explore new methods and conditions rather than routinely performing standardized experiments.

[additional material]

Distinguishing man-made and natural nanoparticles

In addition to the lack of systematic research, there is also a second tangible problem in researching the behaviour of engineered nanoparticles: many engineered nanoparticles consist of chemical compounds that occur naturally in the soil. So far it has been difficult to measure the engineered particles in the environment since it is hard to distinguish them from naturally occurring particles with the same chemical composition.

However, researchers at ETH Zurich’s Department of Chemistry and Applied Biosciences, under the direction of ETH Professor Detlef Günther, have recently established an effective method that makes such a distinction possible in routine investigations. They used a state-of-the-art and highly sensitive mass spectrometry technique (called spICP-TOF mass spectrometry) to determine which chemical elements make up individual nanoparticles in a sample.

In collaboration with scientists from the University of Vienna, the ETH researchers applied the method to soil samples with natural cerium-containing particles, into which they mixed engineered cerium dioxide nanoparticles. Using machine learning methods, which were ideally suited to this particular issue, the researchers were able to identify differences in the chemical fingerprints of the two particle classes. “While artificially produced nanoparticles often consist of a single compound, natural nanoparticles usually still contain a number of additional chemical elements,” explains Alexander Gundlach-Graham, a postdoc in Günther’s group.

The new measuring method is very sensitive: the scientists were able to measure engineered particles in samples with up to one hundred times more natural particles.

The researchers have produced a visualization of their network analysis,

The researchers evaluated the experimental data published in the scientific literature using a network analysis. This analysis reveals which types of nanoparticles (blue) have been studied under which environmental conditions (red). (Visualisations: Thomas Kast)

Here are links and citation for two papers associated with this research,

A network perspective reveals decreasing material diversity in studies on nanoparticle interactions with dissolved organic matter by Nicole Sani-Kast, Jérôme Labille, Patrick Ollivier, Danielle Slomberg, Konrad Hungerbühler, and Martin Scheringer. PNAS 2017, 114: E1756-E1765, DOI: 10.1073/pnas.1608106114

Single-particle multi-element fingerprinting (spMEF) using inductively-coupled plasma time-of-flight mass spectrometry (ICP-TOFMS) to identify engineered nanoparticles against the elevated natural background in soils by Antonia Praetorius, Alexander Gundlach-Graham, Eli Goldberg, Willi Fabienke, Jana Navratilova, Andreas Gondikas, Ralf Kaegi, Detlef Günther, Thilo Hofmann, and Frank von der Kammer. Environonmental Science: Nano 2017, 4: 307-314, DOI: 10.1039/c6en00455e

Both papers are behind a paywall.

Is there a risk of resistance to nanosilver?

Anyone who’s noticed how popular silver has become as an antibacterial, antifungal, or antiviral agent may have wondered if resistance might occur as its use becomes more common. I have two bits on the topic, one from Australia and the other from Canada.

Australia

Researchers in Australia don’t have a definitive statement on the issue but are suggesting more caution (from a March 31, 2017 news item on Nanowerk),

Researchers at the University of Technology Sydney [UTS] warn that the broad-spectrum antimicrobial effectiveness of silver is being put at risk by the widespread and inappropriate expansion of nanosilver use in medical and consumer goods.

As well as their use in medical items such as wound dressings and catheters, silver nanoparticles are becoming ubiquitous in everyday items, including toothbrushes and toothpaste, baby bottles and teats, bedding, clothing and household appliances, because of their antibacterial potency and the incorrect assumption that ordinary items should be kept “clean” of microbes.

Nanobiologist Dr Cindy Gunawan, from the ithree institute at UTS and lead researcher on the investigation, said alarm bells should be ringing at the commercialisation of nanosilver use because of a “real threat” that resistance to nanosilver will develop and spread through microorganisms in the human body and the environment.

A March 31 (?), 2017 University of Technology Sydney press release by Fiona McGill, which originated the news item, expands on the theme,

Dr Gunawan and ithree institute director Professor Liz Harry, in collaboration with researchers at UNSW [University of New South Wales] and abroad, investigated more than 140 commercially available medical devices, including wound dressings and tracheal and urinary catheters, and dietary supplements, which are promoted as immunity boosters and consumed by throat or nasal spray.

Their perspective article in the journal ACS Nano concluded that the use of nanosilver in these items could lead to prolonged exposure to bioactive silver in the human body. Such exposure creates the conditions for microbial resistance to develop.

E. coli bacteria. Photo: Flickr/NIAID

 

The use of silver as an antimicrobial agent dates back centuries. Its ability to destroy pathogens while seemingly having low toxicity on human cells has seen it widely employed, in treating burns or purifying water, for example. More recently, ultra-small (less than 10,000th of a millimetre) silver nanoparticles have been engineered for antimicrobial purposes.  Their commercial appeal lies in superior potency at lower concentrations than “bulk” silver.

“Nanosilver is a proven antimicrobial agent whose reliability is being jeopardised by the commercialisation of people’s fear of bacteria,” Dr Gunawan said.

“Our use of it needs to be far more judicious, in the same way we need to approach antibiotic usage. Nanosilver is a useful tool but we need to be careful, use it wisely and only when the benefit outweighs the risk.

“People need to be made aware of just how widely it is used, but more importantly they need to be made aware that the presence of nanosilver has been shown to cause antimicrobial resistance.”

What is also needed, Dr Gunawan said, is a targeted surveillance strategy to monitor for any occurrence of resistance.

Professor Harry said the findings were a significant contribution to addressing the global antimicrobial resistance crisis.

“This research emphasises the threat posed to our health and that of the environment by the inappropriate use of nanosilver as an antibacterial, particularly in ordinary household and consumer items,” she said.

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

Widespread and Indiscriminate Nanosilver Use: Genuine Potential for Microbial Resistance by Cindy Gunawan, Christopher P. Marquis, Rose Amal, Georgios A. Sotiriou, Scott A. Rice⊥, and Elizabeth J. Harry. ACS Nano, Article ASAP DOI: 10.1021/acsnano.7b01166 Publication Date (Web): March 24, 2017

Copyright © 2017 American Chemical Society

This paper is behind a paywall.

Meanwhile, researchers at the University Calgary (Alberta, Canada) may have discovered what could cause resistance to silver.

Canada

This April 25, 2017 news release on EurekAlert is from the Experimental Biology Annual Meeting 2017,

Silver and other metals have been used to fight infections since ancient times. Today, researchers are using sophisticated techniques such as the gene-editing platform Crispr-Cas9 to take a closer look at precisely how silver poisons pathogenic microbes–and when it fails. The work is yielding new insights on how to create effective antimicrobials and avoid the pitfalls of antimicrobial resistance.

Joe Lemire, a postdoctoral fellow at the University of Calgary, will present his work in this area at the American Society for Biochemistry and Molecular Biology annual meeting during the Experimental Biology 2017 meeting, to be held April 22-26 in Chicago.

“Our overarching goal is to deliver the relevant scientific evidence that would aid policymakers in developing guidelines for when and how silver could be used in the clinic to combat and control infectious pathogens,” said Lemire. “With our enhanced mechanistic understanding of silver toxicity, we also aim to develop novel silver-based antimicrobial therapies, and potentially rejuvenate other antibiotic therapies that bacteria have come to resist, via silver-based co-treatment strategies.”

Lemire and his colleagues are using Crispr-Cas9 genome editing to screen for and delete genes that allow certain bacterial species to resist silver’s antimicrobial properties. [emphasis mine] Although previous methods allowed researchers to identify genes that confer antibiotic resistance or tolerance, Crispr-Cas9 is the first technology to allow researchers to cleanly delete these genes from the genome without leaving behind any biochemical markers or “scars.”

The team has discovered many biological pathways involved in silver toxicity and some surprising ways that bacteria avoid succumbing to silver poisoning, Lemire said. While silver is used to control bacteria in many clinical settings and has been incorporated into hundreds of commercial products, gaining a more complete understanding of silver’s antimicrobial properties is necessary if we are to make the most of this ancient remedy for years to come.

###

Joe Lemire will present this research at 12-2:30 p.m. Tuesday, April 25, [2017] in Hall F, McCormick Place Convention Center (poster B379 939.2) (abstract). Contact the media team for more information or to obtain a free press pass to attend the meeting.

About Experimental Biology 2017

Experimental Biology is an annual meeting comprised of more than 14,000 scientists and exhibitors from six host societies and multiple guest societies. With a mission to share the newest scientific concepts and research findings shaping clinical advances, the meeting offers an unparalleled opportunity for exchange among scientists from across the U.S. and the world who represent dozens of scientific areas, from laboratory to translational to clinical research. http://www.experimentalbiology.org #expbio

About the American Society for Biochemistry and Molecular Biology (ASBMB)

ASBMB is a nonprofit scientific and educational organization with more than 12,000 members worldwide. Founded in 1906 to advance the science of biochemistry and molecular biology, the society publishes three peer-reviewed journals, advocates for funding of basic research and education, supports science education at all levels, and promotes the diversity of individuals entering the scientific workforce. http://www.asbmb.org

Lemire’s co-authors for the work presented at the 2017 annual meeting are: Kate Chatfield-Reed (The University of Calgary), Lindsay Kalan (Perelman School of Medicine), Natalie Gugala (The University of Calgary), Connor Westersund (The University of Calgary), Henrik Almblad (The University of Calgary), Gordon Chua (The University of Calgary), Raymond Turner (The University of Calgary).

For anyone who wants to pursue this research a little further, the most recent paper I can find is this one from 2015,

Silver oxynitrate: An Unexplored Silver Compound with Antimicrobial and Antibiofilm Activity by Joe A. Lemire, Lindsay Kalan, Alexandru Bradu, and Raymond J. Turner. Antimicrobial Agents and Chemotherapy 05177-14, doi: 10.1128/AAC.05177-14 Accepted manuscript posted online 27 April 2015

This paper appears to be open access.

European Commission has issued evaluation of nanomaterial risk frameworks and tools

Despite complaints that there should have been more, there has been some research into risks where nanomaterials are concerned. While additional research would be welcome, it’s perhaps more imperative that standardized testing and risk frameworks are developed so, for example, carbon nanotube safety research in Japan can be compared with the similar research in the Netherlands, the US, and elsewhere. This March 15, 2017 news item on Nanowerk features some research analyzing risk assessment frameworks and tools in Europe,

A recent study has evaluated frameworks and tools used in Europe to assess the potential health and environmental risks of manufactured nanomaterials. The study identifies a trend towards tools that provide protocols for conducting experiments, which enable more flexible and efficient hazard testing. Among its conclusions, however, it notes that no existing frameworks meet all the study’s evaluation criteria and calls for a new, more comprehensive framework.

A March 9, 2017 news alert in the European Commission’s Science for Environment Policy series, which originated the news item, provides more detail (Note: Links have been removed),

Nanotechnology is identified as a key emerging technology in the EU’s growth strategy, Europe 2020. It has great potential to contribute to innovation and economic growth and many of its applications have already received large investments. However,there are some uncertainties surrounding the environmental, health and safety risks of manufactured nanomaterials. For effective regulation, careful scientific analysis of their potential impacts is needed, as conducted through risk assessment exercises.

This study, conducted under the EU-funded MARINA project1, reviewed existing frameworks and tools for risk assessing manufactured nanomaterials. The researchers define a framework as a ‘conceptual paradigm’ of how a risk assessment should be conducted and understood, and give the REACH chemical safety assessment as an example. Tools are defined as implements used to carry out a specific task or function, such as experimental protocols, computer models or databases.

In all, 12 frameworks and 48 tools were evaluated. These were identified from other studies and projects. The frameworks were assessed against eight criteria which represent different strengths, such as whether they consider properties specific to nanomaterials, whether they consider the entire life cycle of a nanomaterial and whether they include careful planning and prioritise objectives before the risk assessment is conducted.

The tools were assessed against seven criteria, such as ease of use, whether they provide quantitative information and if they clearly communicate uncertainty in their results. The researchers defined the criteria for both frameworks and tools by reviewing other studies and by interviewing staff at organisations who develop tools.

The evaluation was thus able to produce a list of strengths and areas for improvement for the frameworks and tools, based on whether they meet each of the criteria. Among its many findings, the evaluation showed that most of the frameworks stress that ‘problem formulation’, which sets the goals and scope of an assessment during the planning process, is essential to avoid unnecessary testing. In addition, most frameworks consider routes of exposure in the initial stages of assessment, which is beneficial as it can exclude irrelevant exposure routes and avoid unnecessary tests.

However, none of the frameworks met all eight of the criteria. The study therefore recommends that a new, comprehensive framework is developed that meets all criteria. Such a framework is needed to inform regulation, the researchers say, and should integrate human health and environmental factors, and cover all stages of the life cycle of a product containing nanomaterials.

The evaluation of the tools suggested that many of them are designed to screen risks, and not necessarily to support regulatory risk assessment. However, their strengths include a growing trend in quantitative models, which can assess uncertainty; for example, one tool analysed can identify uncertainties in its results that are due to gaps in knowledge about a material’s origin, characteristics and use.

The researchers also identified a growing trend in tools that provide protocols for experiments, such as identifying materials and test hazards, which are reproducible across laboratories. These tools could lead to a shift from expensive case-by-case testing for risk assessment of manufactured nanomaterials towards a more efficient process based on groupings of nanomaterials; and ‘read-across’ methods, where the properties of one material can be inferred without testing, based on the known properties of a similar material. The researchers do note, however, that although read-across methods are well established for chemical substances, they are still being developed for nanomaterials. To improve nanomaterial read-across methods, they suggest that more data are needed on the links between nanomaterials’ specific properties and their biological effects.

That’s all, folks.

Plasmonic ‘Goldfinger’: antifungal nail polish with metallic nanoparticles

A March 29,.2017 news item on Nanowerk announces a new kind of nanopolish,

Since ancient times, people have used lustrous silver, platinum and gold to make jewelry and other adornments. Researchers have now developed a new way to add the metals to nail polish with minimal additives, resulting in durable, tinted — and potentially antibacterial — nail coloring.

Using metal nanoparticles in clear nail polish makes it durable and colorful without extra additives.
Credit: American Chemical Society

A March 29, 2017 American Chemical Society (ACS) news release (also on EurekAlert), which originated the news item, adds a little more detail (Note: A link has been removed),

Nail polish comes in a bewildering array of colors. Current coloring techniques commonly incorporate pigment powders and additives. Scientists have recently started exploring the use of nanoparticles in polishes and have found that they can improve their durability and, in the case of silver nanoparticles, can treat fungal toenail infections. Marcus Lau, Friedrich Waag and Stephan Barcikowski wanted to see if they could come up with a simple way to integrate metal nanoparticles in nail polish.

The researchers started with store-bought bottles of clear, colorless nail polish and added small pieces of silver, gold, platinum or an alloy to them. To break the metals into nanoparticles, they shone a laser on them in short bursts over 15 minutes. Analysis showed that the method resulted in a variety of colored, transparent polishes with a metallic sheen. The researchers also used laser ablation to produce a master batch of metal nanoparticles in ethyl acetate, a polish thinner, which could then be added to individual bottles of polish. This could help boost the amount of production for commercialization. The researchers say the technique could also be used to create coatings for medical devices.

The authors acknowledge funding from the INTERREG-Program Germany-Netherlands.

A transparent nail varnish can be colored simply and directly with laser-generated nanoparticles. This does not only enable coloring of the varnish for cosmetic purposes, but also gives direct access to nanodoped varnishes to be used on any solid surface. Therefore, nanoparticle properties such as plasmonic properties or antibacterial effects can be easily adapted to surfaces for medical or optical purposes. The presented method for integration of metal (gold, platinum, silver, and alloy) nanoparticles into varnishes is straightforward and gives access to nanodoped polishes with optical properties, difficult to be achieved by dispersing powder pigments in the high-viscosity liquids. Courtesy: Industrial and Engineering & Chemistry Research

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

Direct Integration of Laser-Generated Nanoparticles into Transparent Nail Polish: The Plasmonic “Goldfinger” by Marcus Lau, Friedrich Waag, and Stephan Barcikowski. Ind. Eng. Chem. Res., 2017, 56 (12), pp 3291–3296 DOI: 10.1021/acs.iecr.7b00039 Publication Date (Web): March 7, 2017

Copyright © 2017 American Chemical Society

This paper is behind a paywall.