Category Archives: health and safety

A review of the nanotechnology in green technology

Michael Berger has written a Nov. 18, 2014 Nanowerk Spotlight article focusing on the ‘green’ in nanotechnology (Note: A link has been removed),

There is a general perception that nanotechnologies will have a significant impact on developing ‘green’ and ‘clean’ technologies with considerable environmental benefits. The associated concept of green nanotechnology aims to exploit nanotech-enabled innovations in materials science and engineering to generate products and processes that are energy efficient as well as economically and environmentally sustainable. These applications are expected to impact a large range of economic sectors, such as energy production and storage, clean up-technologies, as well as construction and related infrastructure industries.

A recent review article in Environmental Health (“Opportunities and challenges of nanotechnology in the green economy”) examines opportunities and practical challenges that nanotechnology applications pose in addressing the guiding principles for a green economy.

Here’s a link to and citation for the review article cited by Berger. It is more focused on occupational health and safety then the title suggests but not surprising when you realize all of the authors are employed by the US National Institute of Occupational Safety and Health (NIOSH),,

Opportunities and challenges of nanotechnology in the green economy by Ivo Iavicoli, Veruscka Leso, Walter Ricciard, Laura L Hodson, and Mark D Hoover. Environmental Health 2014, 13:78 doi:10.1186/1476-069X-13-78 Published:    7 October 2014

© 2014 Iavicoli et al.; licensee BioMed Central Ltd.

This is an open access article.

Here’s the background to the work (from the article; Note: Links have been removed),

The “green economy” concept has been driven into the mainstream of policy debate by global economic crisis, expected increase in global demand for energy by more than one third between 2010 to 2035, rising commodity prices as well as the urgent need for addressing global challenges in domains such as energy, environment and health [1-3].

The term “green economy”, chiefly relating to the principles of sustainable development, was first coined in a pioneering 1989 report for the Government of the United Kingdom by a group of leading environmental economists [1]. The most widely used and reliable definition of “green economy” comes from the United Nations Environment Programme which states that “a green economy is one that results in improved human well-being and social equity, while significantly reducing environmental risks and ecological scarcities. It is low carbon, resource efficient, and socially inclusive” [4].

The green economy concept can indeed play a very useful role in changing the way that society manages the interaction of the environmental and economic domains. In this context, nanotechnology, which is the manipulation of matter in the dimension of 1 to 100 nm, offers the opportunity to produce new structures, materials and devices with unique physico-chemical properties (i.e. small size, large surface area to mass ratio) to be employed in energy efficient as well as economically and environmentally sustainable green innovations [8-12].

Although expected to exert a great impact on a large range of industrial and economic sectors, the sustainability of green nano-solutions is currently not completely clear, and it should be carefully faced. In fact, the benefits of incorporating nanomaterials (NMs) in processes and products that contribute to outcomes of sustainability, might bring with them environmental, health and safety risks, ethical and social issues, market and consumer acceptance uncertainty as well as a strong competition with traditional technologies [13].

The present review examines opportunities and practical challenges that nano-applications pose in addressing the guiding principles for a green economy. Examples are provided of the potential for nano-applications to address social and environmental challenges, particularly in energy production and storage thus reducing pressure on raw materials, clean-up technologies as well as in fostering sustainable manufactured products. Moreover, the review aims to critically assess the impact that green nanotechnology may have on the health and safety of workers involved in this innovative sector and proposes action strategies for the management of emerging occupational risks.

The potential nanotechnology impact on green innovations

Green nanotechnology is expected to play a fundamental role in bringing a key functionality across the whole value chain of a product, both through the beneficial properties of NMs included as a small percentage in a final device, as well as through nano-enabled processes and applications without final products containing any NMs [13,14]. However, most of the potential green nano-solutions are still in the lab/start-up phase and very few products have reached the market to date. Further studies are necessary to assess the applicability, efficiency and sustainability of nanotechnologies under more realistic conditions, as well as to validate NM enabled systems in comparison to existing technologies. The following paragraphs will describe the potential fields of application for green nanotechnology innovations.

Intriguingly, there’s no mention (that I could find) of soil remediation (clean-up) although there is reference to water remediation.  As for occupational health and safety and nanotechnology, the authors have this to say (Note: Links have been removed),

In this context according to the proposed principles for green economy, it is important that society, scientific community and industry take advantage of opportunities of nanotechnology while overcoming its practical challenges. However, not all revolutionary changes are sustainable per se and a cautious assessment of the benefits addressing economic, social and environmental implications, as well as the occupational health and safety impact is essential [95,96]. This latter aspect, in particular, should be carefully addressed, in consideration of the expected widespread use of nanotechnology and the consequent increasing likelihood of NM exposure in both living and occupational environments. Moreover, difficulties in nano-manufacturing and handling; uncertainty concerning stability of nano-innovations under aggressive or long-term operation (i.e. in the case of supercapacitors with nano-structured electrode materials or nano-enabled construction products); the lack of information regarding the release and fate of NMs in the environment (i.e. NMs released from water and wastewater treatment devices) as well as the limited knowledge concerning the NM toxicological profile, even further support the need for a careful consideration of the health and safety risks derived from NM exposure.Importantly, as shown in Figure 1, a number of potentially hazardous exposure conditions can be expected for workers involved in nanotechnology activities. In fact, NMs may have significant, still unknown, hazards that can pose risks for a wide range of workers: researchers, laboratory technicians, cleaners, production workers, transportation, storage and retail workers, employees in disposal and waste facilities and potentially, emergency responders who deal with spills and disasters of NMs who may be differently exposed to these potential, innovative xenobiotics.

The review article is quite interesting, albeit its precaution-heavy approach, but if you don’t have time, Berger summarizes the article. He also provides links to related articles he has written on the subjects of energy storage, evaluating ‘green’ nanotechnology in a full life cycle assessment, and more.

Researching a curcumin delivery system—a nutraceutical story

A Nov. 6, 2014 news item on ScienceDaily features research on delivering curcumin’s (a constituent of turmeric) health benefits more efficiently (there is a twist; for the impatient, you may want to scroll down to where I provide an excerpt from the university’s news release) from Ohio State University (US),

The health benefits of over-the-counter curcumin supplements might not get past your gut, but new research shows that a modified formulation of the spice releases its anti-inflammatory goodness throughout the body.

Curcumin is a naturally occurring compound found in the spice turmeric that has been used for centuries as an Ayurvedic medicine treatment for such ailments as allergies, diabetes and ulcers.

Anecdotal and scientific evidence suggests curcumin promotes health because it lowers inflammation, but it is not absorbed well by the body. Most curcumin in food or supplements stays in the gastrointestinal tract, and any portion that’s absorbed is metabolized quickly.

A Nov. 6, 2014 Ohio State University news release by Emily Caldwell (also on EurekAlert), which originated the news item, explains the interest in curcumin in more detail and describes the research in more detail,

Many research groups are testing the compound’s effects on disorders ranging from colon cancer to osteoarthritis. Others, like these Ohio State University scientists, are investigating whether enabling widespread availability of curcumin’s biological effects to the entire body could make it useful both therapeutically and as a daily supplement to combat disease.

“There’s a reason why this compound has been used for hundreds of years in Eastern medicine. And this study suggests that we have identified a better and more effective way to deliver curcumin and know what diseases to use it for so that we can take advantage of its anti-inflammatory power,” said Nicholas Young, a postdoctoral researcher in rheumatology and immunology at Ohio State and lead author of the study.

Curcumin powder was mixed with castor oil and polyethylene glycol in a process called nano-emulsion (think vinaigrette salad dressing), creating fluid teeming with microvesicles that contain curcumin. This process allows the compound to dissolve and be more easily absorbed by the gut to enter the bloodstream and tissues.

Feeding mice this curcumin-based drug shut down an acute inflammatory reaction by blocking activation of a key protein that triggers the immune response. The researchers were also the first to show that curcumin stops recruitment of specific immune cells that, when overactive, are linked to such problems as heart disease and obesity.

Young and his colleagues, including co-senior authors Lai-Chu Wu and Wael Jarjour of the Division of Rheumatology and Immunology at Ohio State’s Wexner Medical Center, now want to know if curcumin in this form can counter the chronic inflammation that is linked to sickness and age-related frailty. They have started with animal studies testing nano-emulsified curcumin’s ability to prevent or control inflammation in a lupus model.

“We envision that this nutraceutical could be used one day both as a daily supplement to help prevent certain diseases and as a therapeutic drug to help combat the bad inflammation observed in many diseases,” Young said. “The distinction will then be in the amount given – perhaps a low dose for daily prevention and higher doses for disease suppression.”

The term nutraceutical refers to foods or nutrients that provide medical or health benefits.

This news release notes the latest research is built on previous work,

The curcumin delivery system was created in Ohio State’s College of Pharmacy, and these researchers previously showed that concentrations of the emulsified curcumin in blood were more than 10 times higher than of curcumin powder suspended in water.

A more precise description of the current research is then provided (from the news release),

… From there, the researchers launched experiments in mice and cell cultures, generating artificial inflammation and comparing the effects of the nano-emulsified curcumin with the effects of curcumin powder in water or no treatment at all. [emphasis mine]

The researchers injected mice with lipopolysaccharide, a bacteria cell wall extract that stimulates an immune reaction in animals. Curcumin can target many molecules, but the research team zeroed in on NF-kB, a protein that is known to play an important role in the immune response.

In a specialized imaging machine, mice receiving plain curcumin lit up with bioluminescent signals indicating that NF-kB was actively triggering an immune response, while mice receiving nano-emulsified curcumin showed minimal signs – a 22-fold reduction – that the protein had been activated at all.

Knowing that curcumin delivered in this way could shut down NF-kB activation throughout the animals’ bodies, researchers looked for further details about the compound’s effects on inflammation. They found that nano-emulsified curcumin halted the recruitment of immune cells called macrophages that “eat” invading pathogens but also contribute to inflammation by secreting pro-inflammatory chemicals. And in cells isolated from human blood samples, macrophages were stopped in their tracks.

“This macrophage-specific effect of curcumin had not been described before,” Young said. “Because of that finding, we propose nano-emulsified curcumin has the best potential against macrophage-associated inflammation.”

Inflammation triggered by overactive macrophages has been linked to cardiovascular disease, disorders that accompany obesity, Crohn’s disease, rheumatoid arthritis, inflammatory bowel disease, diabetes and lupus-related nephritis.

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

Oral Administration of Nano-Emulsion Curcumin in Mice Suppresses Inflammatory-Induced NFκB Signaling and Macrophage Migration by Nicholas A. Young, Michael S. Bruss, Mark Gardner, William L. Willis, Xiaokui Mo, Giancarlo R. Valiente, Yu Cao, Zhongfa Liu, Wael N. Jarjour, and Lai-Chu Wu. PLOS ONE Published: November 04, 2014 DOI: 10.1371/journal.pone.0111559

This paper is open accesss.

I have an Oct. 1, 2014 posting which features research on curcumin for healing wounds and on tumerone for stimulating the formation of stem cells in the brain.

Nanozen: protecting us from nanoparticles (maybe)

Friday, Oct. 24, 2014 the Vancouver Sun (Canada) featured a local nanotechnology company, Nanozen in an article by ‘digital life’ writer, Gillian Shaw. Unfortunately, the article is misleading. Before noting the issues, it should be said that most reporters don’t have much time to prepare stories and are often asked to write on topics that are new or relatively unknown to them. It is a stressful position to be in especially when one is reliant on the interviewee’s expertise and agenda. As for the interviewee, sometimes scientists get excited and enthused and don’t speak with their usual caution.

The article starts off in an unexceptionable manner,

Vancouver startup Nanozen is a creating real-time, wearable particle sensor for use in mines, mills and other industrial locations where dust and other particles can lead to dangerous explosions and debilitating respiratory diseases.

The company founder and, presumably, lead researcher Winnie Chu is described as a former professor of environmental health at the University of British Columbia who has devoted herself to developing a new means of monitoring particles, in particular nanoparticles. Chu is quoted as saying this,

“The current technology is not sufficient to protect workers or the community when concentrations exceed the acceptable level,” she said.

It seems ominous and is made more so with this,

Chu said more than 90 per cent of the firefighters who responded to the 9/11 disaster developed lung disease, having walked into a site full of small and very damaging particles in the air.

“Those nanoparticles go deep into your lungs and cause inflammation and other problems,” Chu said.

It seems odd to mention this particular disaster. The lung issues for the firefighters, first responders and people living close to the site of World Trade Centers collapse are due to a complex mix of materials in the air. Most of the research I can find focuses on micrsoscale particles such as the work from the University of California at Davis’s Delta Group (Detection and Evaluation of the Long-Range Transport of Aerosols). From the Group’s World Trade Center webpage,

The fuming World Trade Center debris pile was a chemical factory that exhaled pollutants in particularly dangerous forms that could penetrate deep into the lungs of workers at Ground Zero, says a new study by UC Davis air-quality experts.

You can find the group’s presentation (-Presentation download (WTC aersols ACS 2003.ppt; 7,500kb)) to an American Chemical Society meeting in 2003 along more details such as this on their webpage,

The conditions would have been “brutal” for people working at Ground Zero without respirators and slightly less so for those working or living in immediately adjacent buildings, said the study’s lead author, Thomas Cahill, a UC Davis professor emeritus of physics and atmospheric science and research professor in engineering.

“Now that we have a model of how the debris pile worked, it gives us a much better idea of what the people working on and near the pile were actually breathing,” Cahill said. “Our first report was based on particles that we collected one mile away. This report gives a reasonable estimate of what type of pollutants were actually present at Ground Zero.

“The debris pile acted like a chemical factory. It cooked together the components of the buildings and their contents, including enormous numbers of computers, and gave off gases of toxic metals, acids and organics for at least six weeks.”

The materials found by this group were not at the nanoscale. In fact, the focus was then and subsequently on materials such as glass shards, asbestos, and metallic aerosols at the microscale, all of which can cause well documented health problems. No doubt effective monitoring would have been helpful It seems the critical issue in the early stages of the disaster was access to a respirator. Also, effective monitoring at later stages which did not seem to have happened would have been a good idea.

A 2004 (?) New York Magazine article by Jennifer Senior titled ‘Fallout‘ had this to say about the air content,

Here, today, is what we know about the dust and air at ground zero: It contained glass shards, pulverized concrete, and many carcinogens, including hundreds of thousands of pounds of asbestos, tens of thousands of pounds of lead, mercury, cadmium, dioxins, PCBs, and polycyclic aromatic hydrocarbons, or PAHs. It also contained benzene. According to a study done by the U.S. Geological Survey, the dust was so caustic in places that its pH exceeded that of ammonia. Thomas Cahill, a scientist who analyzed the plumes from a rooftop one mile away, says that the levels of acids, insoluble particles, high-temperature organic materials, and metals were in most cases higher in very fine particles (which can slip deep into the lungs) than anyplace ever recorded on earth, including the oil fires of Kuwait.

The article describes at some length the problems for first responders and for those who later moved back into their homes nearby the disaster site under the impression the air was clean.

Getting back to the nanoscale, there were carbon nanotubes (CNTs) present as this 2009 research paper, Case Report: Lung Disease in World Trade Center Responders Exposed to Dust and Smoke: Carbon Nanotubes Found in the Lungs of World Trade Center Patients and Dust Samples, noted in relation to a sample of seven patients,

It may well be the most frequent injury pattern in exposed patients with severe respiratory impairment. b) Interstitial disease was present in four cases (Patients A, B, C, and E), characterized by a generally bronchiolocentric pattern of interstitial inflammation and fibrosis of variable severity. The lungs of these patients contained large amounts of silicates, and three of them showed nanotubes.

CNT of commercial origin, common now, would not have been present in substantial numbers in the WTC complex before the disaster in 2001. However, the high temperatures generated during the WTC disaster as a result of the combustion of fuel in the presence of carbon and metals would have been sufficient to locally generate large numbers of CNT. This scenario could have caused the generation of CNT that we have noted in the dust samples and in the lung biopsy specimens.

Given that CNTs are more common now, it would suggest that a monitor for nanoscale materials such as Chu’s proposed equipment could be an excellent idea. Unfortunately, it’s not clear what Chu is trying to achieve as she appears to make a blunder in the article,

Chu said environmental agencies require testing to distinguish between particles equal to or less than 10 microns and smaller particles 2.5 microns or less.

“When we inhale we inhale both size particles but they go into different parts of the lung,” said Chu, who said research shows the smaller the particle the higher the toxicity. [emphasis mine] The monitor she has developed can detect particles as small as one micron and even less.

The word ‘nanoparticle’ is often used generically to include, CNTs, quantum dots, silver nanoparticles, etc. as Chu seems to be doing throughout the article. The only nanomaterial/nanoparticle that researchers agree unequivocally cause lung problems are long carbon nanotubes which resemble asbestos fibres. This is precisely the opposite of Chu’s statement.

For validation, you can conduct your own search or you can check Swiss toxicologist Harald Krug’s (mentioned in my Nanosafety research: a quality control issue posting of Oct. 30, 2014) statement that most health and safety research of nanomaterials and the resultant conclusions are problematic. But he too is unequivocal with regard long carbon nanotubes (from Krug’s study, Nanosafety Research—Are We on the Right Track?).

Comparison of instillation and inhalation experiments: instillation studies have to be carried out with relatively high local doses and, thus, more often meet overload conditions than inhalation studies. Transient inflammatory effects have been observed frequently in both types of lung exposure, irrespective of the type of ENMs used for the experiment. This finding suggests an unspecific particle effect; moreover, the biological response seems to be comparable to a scenario involving exposure to fine dust. Prominent exceptions are long and rigid carbon nanotube (CNT) bundles, which induce a severe tissue reaction (chronic inflammation) that may ultimately result in tumor formation. Overall, the evaluated studies showed no indication of a “nanospecific” effect in the lung. [from the Summary section; 2nd bulleted point]

You can find the Nanozen website here but there doesn’t appear to be any information on the site yet. These search terms ‘about’, ‘team’, ‘technology’, and ‘product’ yielded no results on website as of Oct. 30, 2014 at 1000 hours PDT.

Nanosafety research: a quality control issue

Toxicologist Dr. Harald Krug has published a review of several thousand studies on nanomaterials safety exposing problematic research methodologies and conclusions. From an Oct. 29, 2014 news item on Nanowerk (Note: A link has been removed),

Empa [Swiss Federal Laboratories for Materials Science and Technology] toxicologist Harald Krug has lambasted his colleagues in the journal Angewandte Chemie (“Nanosafety Research—Are We on the Right Track?”). He evaluated several thousand studies on the risks associated with nanoparticles and discovered no end of shortcomings: poorly prepared experiments and results that don’t carry any clout. Instead of merely leveling criticism, however, Empa is also developing new standards for such experiments within an international network.

An Oct. 29, 2014 Empa press release (also on EurekAlert), which originated the news item, describes the new enthusiasm for research into nanomaterials and safety,

Researching the safety of nanoparticles is all the rage. Thousands of scientists worldwide are conducting research on the topic, examining the question of whether titanium dioxide nanoparticles from sun creams can get through the skin and into the body, whether carbon nanotubes from electronic products are as hazardous for the lungs as asbestos used to be or whether nanoparticles in food can get into the blood via the intestinal flora, for instance. Public interest is great, research funds are flowing – and the number of scientific projects is skyrocketing: between 1980 and 2010, a total of 5,000 projects were published, followed by another 5,000 in just the last three years. However, the amount of new knowledge has only increased marginally. After all, according to Krug the majority of the projects are poorly executed and all but useless for risk assessments.

The press release goes on to describe various pathways into the body and problems with research methodologies,

How do nanoparticles get into the body?

Artificial nanoparticles measuring between one and 100 nanometers in size can theoretically enter the body in three ways: through the skin, via the lungs and via the digestive tract. Almost every study concludes that healthy, undamaged skin is an effective protective barrier against nanoparticles. When it comes to the route through the stomach and gut, however, the research community is at odds. But upon closer inspection the value of many alarmist reports is dubious – such as when nanoparticles made of soluble substances like zinc oxide or silver are being studied. Although the particles disintegrate and the ions drifting into the body are cytotoxic, this effect has nothing to do with the topic of nanoparticles but is merely linked to the toxicity of the (dissolved) substance and the ingested dose.

Laboratory animals die in vain – drastic overdoses and other errors

Krug also discovered that some researchers maltreat their laboratory animals with absurdly high amounts of nanoparticles. Chinese scientists, for instance, fed mice five grams of titanium oxide per kilogram of body weight, without detecting any effects. By way of comparison: half the amount of kitchen salt would already have killed the animals. A sloppy job is also being made of things in the study of lung exposure to nanoparticles: inhalation experiments are expensive and complex because a defined number of particles has to be swirled around in the air. Although it is easier to place the particles directly in the animal’s windpipe (“instillation”), some researchers overdo it to such an extent that the animals suffocate on the sheer mass of nanoparticles.

While others might well make do without animal testing and conduct in vitro experiments on cells, here, too, cell cultures are covered by layers of nanoparticles that are 500 nanometers thick, causing them to die from a lack of nutrients and oxygen alone – not from a real nano-effect. And even the most meticulous experiment is worthless if the particles used have not been characterized rigorously beforehand. Some researchers simply skip this preparatory work and use the particles “straight out of the box”. Such experiments are irreproducible, warns Krug.

As noted in the news item, the scientists at Empa have devised a solution to some to of the problems (from the press release),

The solution: inter-laboratory tests with standard materials
Empa is thus collaborating with research groups like EPFL’s Powder Technology Laboratory, with industrial partners and with Switzerland’s Federal Office of Public Health (FOPH) to find a solution to the problem: on 9 October the “NanoScreen” programme, one of the “CCMX Materials Challenges”, got underway, which is expected to yield a set of pre-validated methods for lab experiments over the next few years. It involves using test materials that have a closely defined particle size distribution, possess well-documented biological and chemical properties and can be altered in certain parameters – such as surface charge. “Thanks to these methods and test substances, international labs will be able to compare, verify and, if need be, improve their experiments,” explains Peter Wick, Head of Empa’s laboratory for Materials-Biology Interactions.

Instead of the all-too-familiar “fumbling around in the dark”, this would provide an opportunity for internationally coordinated research strategies to not only clarify the potential risks of new nanoparticles in retrospect but even be able to predict them. The Swiss scientists therefore coordinate their research activities with the National Institute of Standards and Technology (NIST) in the US, the European Commission’s Joint Research Center (JRC) and the Korean Institute of Standards and Science (KRISS).

Bravo! and thank you Dr. Krug and Empa for confirming something I’ve suspected due to hints from more informed commentators. Unfortunately my ignorance. about research protocols has not permitted me to undertake a better analysis of the research. ,

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

Nanosafety Research—Are We on the Right Track? by Prof. Dr. Harald F. Krug. Angewandte Chemie International Edition DOI: 10.1002/anie.201403367 Article first published online: 10 OCT 2014

This is an open access paper.

Lung injury, carbon nanotubes, and aluminum oxide

It’s pretty much undisputed that long, multi-walled carbon nanotubes (MWCNTs) are likely to present a serious health hazard given their resemblance to asbestos fibres. It’s a matter of some concern that has resulted in a US National Institute of Occupational Safety and Health (NIOSH) recommendation for workplace exposure to all carbon nanotubes that is stringent. (My April 26, 2013 posting features the recommendation.)

Some recent research from North Carolina State University (NCSU) suggests that there may be a way to make long, multi-walled carbon nanotubes safer. From an Oct. 3, 2014 news item on Nanowerk,

A new study from North Carolina State University and the National Institute of Environmental Health Sciences (NIEHS) finds that coating multiwalled carbon nanotubes (CNTs) with aluminum oxide reduces the risk of lung scarring, or pulmonary fibrosis, in mice.

“This could be an important finding in the larger field of work that aims to predict and prevent future diseases associated with engineered nanomaterials,” says James Bonner, a professor of environmental and molecular toxicology at NC State …

An Oct. 3, 2014 NCSU news release, which originated the news item, describes the research in a little more detail,

Multiwalled CNTs have a wide array of applications, ranging from sporting goods to electronic devices. And while these materials have not been associated with adverse health effects in humans, research has found that multi-walled CNTs can cause pulmonary fibrosis and lung inflammation in animal models.

“Because multiwalled CNTs are increasingly used in a wide variety of products, it seems likely that humans will be exposed to them at some point,” Bonner says. “That means it’s important for us to understand these materials and the potential risk they pose to human health. The more we know, the better we’ll be able to engineer safer materials.”

For this study, the researchers used atomic layer deposition to coat multiwalled CNTs with a thin film of aluminum oxide and exposed mice to a single dose of the CNTs, via inhalation.

The researchers found that CNTs coated with aluminum oxide were significantly less likely to cause pulmonary fibrosis in mice. However, the coating of aluminum oxide did not prevent lung inflammation.

“The aluminum oxide coating doesn’t eliminate health risks related to multi-walled CNTs,” Bonner says, “but it does lower them.”

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

Atomic Layer Deposition Coating of Carbon Nanotubes with Aluminum Oxide Alters Pro-Fibrogenic Cytokine Expression by Human Mononuclear Phagocytes In Vitro and Reduces Lung Fibrosis in Mice In Vivo by Alexia J. Taylor, Christina D. McClure, Kelly A. Shipkowski, Elizabeth A. Thompson, Salik Hussain, Stavros Garantziotis, Gregory N. Parsons, and James C. Bonner. Published: September 12, 2014 DOI: 10.1371/journal.pone.0106870

This is an open access article.

The researchers offered this conclusion (part of the paper’s abstract),

These findings indicate that ALD [atomic layer deposition] thin film coating of MWCNTs with Al2O3 reduces fibrosis in mice and that in vitro phagocyte expression of IL-6, TNF-α, and OPN, but not IL-1β, predict MWCNT-induced fibrosis in the lungs of mice in vivo.

However, what I found most striking was this from the paper’s Discussion (section),

While the Al2O3 coating on MWCNTs appears to be the major factor that alters cytokine production in THP-1 and PBMCs in vitro, nanotube length is still likely an important determinant of the inflammatory and fibroproliferative effects of MWCNTs in the lung in vivo. In general, long asbestos fibers or rigid MWCNTs (i.e., >20 µm) remain in the lung and are much more persistent than shorter fibers or nanotubes [20]. Therefore, the nanotube fragments resulting from breakage of A-MWCNTs coated with 50 or 100 ALD cycles of Al2O3 would likely be cleared from the lungs more rapidly than uncoated long MWCNTs or those coated with only 10 ALD cycles of Al2O3. We observed that the fracturing of A-MWCNTs occurred only after sonication prior to administration to cells in vitro or mice in vivo. However, unsonicated A-MWCNTs could be more likely to fracture over time in tissues as compared to U-MWCNTs [uncoated]. We did not address the issue of A-MWCNT clearance before or after fracturing in the present study, but future work should focus the relative clearance rates from the lungs of mice exposed to A-MWCNTs in comparison to U-MWCNTs. Another potentially important consideration is whether or not ALD coating with Al2O3 alters the formation of a protein corona around MWCNTs. It is possible that differences in cytokine levels in the supernatants from cells treated with U- or A-MWCNTs could be due to differences in protein corona formation around functionalized MWCNTs that could modify the adsorptive capacity of the nanomaterial. Characterization of the protein corona and the adsorptive capacity for cytokines after ALD modification of MWCNTs should be another important focus for future work. [emphases mine]

In other words, researchers think coating long, MWCNTs with a certain type of aluminum might be safer due to its effect on various proteins and because coated MWCNTs are likely to fracture into smaller pieces and we know that short MWCNTs don’t seem to present a problem when inhaled.

Of course, there’s the research from Duke University (my Oct. 3, 2014 post) which suggests CNTs could present a different set of problems over time as they accumulate in the environment.

Carbon nanotube accumulation in Duke University’s (US) mesocosm

This Oct. 1, 2014 news item on ScienceDaily about carbon nanotubes accumulating in the wetlands is carefully worded,

A Duke University team has found that nanoparticles called single-walled carbon nanotubes accumulate quickly in the bottom sediments of an experimental wetland setting, an action they say could indirectly damage the aquatic food chain. [emphasis mine]

The results indicate little risk to humans ingesting the particles through drinking water, say scientists at Duke’s Center for the Environmental Implications of Nanotechnology (CEINT). But the researchers warn that, based on their previous research, the tendency for the nanotubes to accumulate in sediment could indirectly damage the aquatic food chain in the long term if the nanoparticles provide “Trojan horse” piggyback rides to other harmful molecules. [emphases mine]

There’s a lot of hedging (could, if) in the way this research is being described. I imagine the researchers are indicating they have concerns but have no wish to stimulate panic and worry.

An Oct. 1, 2014 Duke University news release (also on EurekAlert), which originated the news item, goes on to explain the interest in carbon nanotubes specifically,

Carbon nanotubes are rapidly becoming more common because of their usefulness in nanoelectric devices, composite materials and biomedicine.

The Duke study was done using small-scale replications of a wetland environment, called “mesocosms,” that include soil, sediments, microbes, insects, plants and fish. These ecosystems-in-a-box are “semi-closed,” meaning they get fresh air and rainwater but don’t drain to their surroundings. While not perfect representations of a natural environment, mesocosms provide a reasonable compromise between the laboratory and the real world.

“The wetland mesocosms we used are a much closer approximation of the natural processes constantly churning in the environment,” said Lee Ferguson, associate professor of civil and environmental engineering at Duke. “Although it’s impossible to know if our results are fully accurate to natural ecosystems, it is clear that the processes we’ve seen should be considered by regulators and manufacturers.”

Ferguson and his colleagues dosed the mesocosms with single-walled carbon nanotubes and measured their concentrations in the water, soil and living organisms during the course of a year. They found that the vast majority of the nanoparticles quickly accumulated in the sediment on the “pond” floor. However, they found no sign of nanoparticle buildup in any plants, insects or fish living in the mesocosms.

That sounds marvelous and then the researchers provide a few facts about carbon nanotubes,

While this is good news for humans or other animals drinking water after a potential spill or other contamination event, the accumulation in sediment does pose concerns for both sediment-dwelling organisms and the animals that eat them. Previous research has shown that carbon nanotubes take a long time to degrade through natural processes — if they do at all — and any chemical that binds to them cannot easily be degraded either.

“These nanoparticles are really good at latching onto other molecules, including many known organic contaminants,” said Ferguson. “Coupled with their quick accumulation in sediment, this may allow problematic chemicals to linger instead of degrading. The nanoparticle-pollutant package could then be eaten by sediment-dwelling organisms in a sort of ‘Trojan horse’ effect, allowing the adsorbed contaminants to accumulate up the food chain.

“The big question is whether or not these pollutants can be stripped away from the carbon nanotubes by these animals’ digestive systems after being ingested,” continued Ferguson. “That’s a question we’re working to answer now.”

It’s good to see this research is being followed up so quickly. I will keep an eye out for it and, in the meantime, wonder how the followup research will be conducted and what animals will be used for the tests.

Here’s a link to and a citation for the researchers’ most recent paper on possible ‘Trojan’ carbon nanotubes,

Fate of single walled carbon nanotubes in wetland ecosystems by Ariette Schierz, Benjamin Espinasse, Mark R. Wiesner, Joseph H. Bisesi, Tara Sabo-Attwood, and P. Lee Ferguson. Environ. Sci.: Nano, 2014, Advance Article DOI: 10.1039/C4EN00063C First published online 03 Sep 2014

This is an open access paper.

I have written about Duke University and its nanoparticle research in mesocosms before. Most recently, there was a Feb. 28, 2013 posting about work on silver nanoparticles which mentions research in the ‘mesocosm’ (scroll down about 50% of the way). There’s also an Aug. 15, 2011 posting which describes the ‘mesocosm’ project at some length.

For anyone unfamiliar with the Trojan horse story (from its Wikipedia entry; Note: Links have been removed),

The Trojan Horse is a tale from the Trojan War about the subterfuge that the Greeks used to enter the city of Troy and win the war. In the canonical version, after a fruitless 10-year siege, the Greeks constructed a huge wooden horse, and hid a select force of men inside. The Greeks pretended to sail away, and the Trojans pulled the horse into their city as a victory trophy. That night the Greek force crept out of the horse and opened the gates for the rest of the Greek army, which had sailed back under cover of night. The Greeks entered and destroyed the city of Troy, decisively ending the war.

Live webcast about data journalism on July 30, 2014 and a webinar featuring the 2014 NNI (US National Nanotechnology Initiative) EHS (Environment, Health and Safety) Progress Review on July 31, 2014

The Woodrow Wilson International Center for Scholars is hosting a live webcast on data journalism scheduled for July 30, 2014. For those us who are a little fuzzy as to what the term ‘data journalism’ means, this is probably a good opportunity to find out as per the description in the Wilson Center’s July 23, 2014 email announcement,

What is data journalism? Why does it matter? How has the maturing field of data science changed the direction of journalism and global investigative reporting? Our speakers will discuss the implications for policymakers and institutional accountability, and how the balance of power in information gathering is shifting worldwide, with implications for decision-making and open government.

This event will be live webcast and you may follow it on twitter @STIPcommonslab and #DataJournalism

Wednesday, July 30th, 2014
10am – 12pm EST
5th Floor Conference Room
[Woodrow Wilson International Center for Scholars
Ronald Reagan Building and International Trade Center
One Woodrow Wilson Plaza – 1300 Pennsylvania Ave., NW, Washington, DC 20004-3027
T 1-202-691-4000]

Speakers:

Alexander B. Howard
Writer and Editor, TechRepublic and founder of the blog “E Pluribus Unum.” Previously, he was a fellow at the Tow Center for Digital Journalism at Columbia University, the Ash Center at Harvard University and the Washington Correspondent for O’Reilly Media.

Kalev H. Leetaru
Yahoo! Fellow at Georgetown University, a Council Member of the World Economic Forum’s Global Agenda Council on the Future of Government, and a Foreign Policy Magazine Top 100 Global Thinker of 2013. For nearly 20 years he has been studying the web and building systems to interact with and understand the way it is reshaping our global society.

Louise Lief (Moderator)
Public Policy Scholar at the Wilson Center. Her project, “Science and the Media” explores innovative ways to make environmental science more accessible and useful to all journalists. She is investigating how new technologies and civic innovation tools can benefit both the media and science.

I believe you need to RSVP if you are attending in person but it’s not necessary for the livestream.

The other announcement comes via a July 23, 2014 news item on Nanowerk,

The National Nanotechnology Coordination Office (NNCO) will hold a public webinar on Thursday, July 31, 2014, to provide a forum to answer questions related to the “Progress Review on the Coordinated Implementation of the National Nanotechnology Initiative (NNI) 2011 Environmental, Health, and Safety Research Strategy.”

The full notice can be found on the US nano.gov website,

When: The webinar will be live on Thursday, July 31, 2014 from 12:00 pm-1 pm.
Where: Click here to register for the online webcast

While it’s open to the public, I suspect this is an event designed largely for highly interested parties such as the agencies involved in EHS activities, nongovernmental organizations that act as watchdogs, and various government policy wonks. Here’s how they describe their proposed discussions (from the event notice page),

Discussion during the webinar will focus on the research activities undertaken by NNI agencies to advance the current state of the science as highlighted in the Progress Review. Representative research activities as provided in the Progress Review will be discussed in the context of the 2011 NNI EHS Research Strategy’s six core research areas: Nanomaterial Measurement Infrastructure, Human Exposure Assessment, Human Health, the Environment, Risk Assessment and Risk Management Methods, and Informatics and Modeling.

How: During the question-and-answer segment of the webinar, submitted questions will be considered in the order received. A moderator will identify relevant questions and pose them to the panel of NNI agency representatives. Due to time constraints, not all questions may be addressed.  The moderator reserves the right to group similar questions and to skip questions, as appropriate. The NNCO will begin accepting questions and comments via email ([email protected]) at 1 pm on Thursday, July 24th (EDT) until the close of the webinar at 1 pm (EDT) on July 31st.

The Panelists:  The panelists for the webinar are subject matter experts from the Federal Government.

Additional Information: A public copy of the “Progress Review on the Coordinated Implementation of the National Nanotechnology Initiative 2011 Environmental, Health, and Safety Research Strategy” can be accessed at www.nano.gov/2014EHSProgressReview. The 2011 NNI EHS Research Strategy can be accessed at www.nano.gov/node/681.
– See more at: http://www.nano.gov/node/1166#sthash.Ipr0bFeP.dpuf

Carbon nanotubes: OCSiAl’s deal in Korea and their effect on the body after one year

I have two news items related only by their focus on carbon nanotubes. First, there’s a July 3, 2014 news item on Azonano featuring OCSiAl’s deal with a Korean company announced at NANO KOREA 2014,

At NANO KOREA 2014 OCSiAl announced an unprecedentedly large-scale deal with Korean company Applied Carbon Nano Technology [ACN] Co., Ltd. – one of the key industry players.

OCSiAl, the dominating graphene tubes manufacturer, that successfully presented its products and technology in Europe and USA, now to enter Asian nanotech markets. At NANO KOREA 2014 the company introduced TUBALL, the universal nanomodifier of materials featuring >75% of single wall carbon nanotubes, and announced signing of supply agreement with Applied Carbon Nano Technology Co., Ltd. (hereinafter referred to as ACN), a recognized future-oriented innovative company.

A July 3, 2014 OCSiAl news release, which originated the news item, describes the memorandum of understanding (MOU) in greater detail,

Under this MoU ACN would buy 100 kg of TUBALL. The upcoming deal is the first of OCSiAl’s Korean contracts to be performed in 2015 and it turns up the largest throughout SWCNT market, which annual turnover recently hardly reached 500 kg. The agreement is exceptionally significant as it opens fundamental opportunities for manufacturing of new nanomaterial-based product with the unique properties that were not even possible before.

“OCSiAl’s entry to Korean market required thorough preparation. We invested time and efforts to prove that our company, our technology and our products worth credibility, – says Viktor Kim, OCSiAl Vice President, – we urged major playmakers to take TUBALL for testing to verify the quality and effectiveness. We believe that ACN is more than an appropriate partner to start – they are experts at the market and they understand its future perspectives very clearly. We believe that mutually beneficial partnership with ACN will path the way for future contracts, since it will become indicative to other companies in Asia and all over the world”.

“It comes as no surprise that OCSiAl’s products here in Korea will be in a great demand soon. The country strives to become world’s leader in advanced technology, and we do realize the benefits of nanomaterial’s exploitation. TUBALL is a truly versatile additive which may be used across many market sectors, where adoption of new materials with top-class performance is essential”, – says Mr. Dae-Yeol Lee, CEO of ACN.

OCSiAl’s entering to Korean market will undoubtedly have a high-reaching impact on the industry. The recent merger with American Zyvex Technologies made OCSiAl the not only the world’s largest nanomaterial producer but a first-rate developer of modifiers of different materials based on carbon nanotubes. To its Korean partners OCSiAl offers TUBALL, the raw ‘as produced’ SWCNT material and masterbatches, which can be either custom-made or ready-to-use mixtures for different applications, including li-ion batteries, car tires, transparent conductive coatings and many others. “Since Korea is increasingly dynamic, our success here will build on continuous development of our product, – adds Viktor Kim, – And we are constantly working on new applications of graphene tubes to meet sophisticated demands of nanotech-savvy Korean consumers”.

OCSiAl’s Zyvex acquisition was mentioned in a June 23, 2014 posting here.

My second tidbit concerns a July 4, 2014 news item on Nanowerk about carbon nanotubes and their effect on the body (Note: A link has been removed),

Having perfected an isotope labeling method allowing extremely sensitive detection of carbon nanotubes in living organisms, CEA and CNRS researchers have looked at what happens to nanotubes after one year inside an animal. Studies in mice revealed that a very small percentage (0.75%) of the initial quantity of nanotubes inhaled crossed the pulmonary epithelial barrier and translocated to the liver, spleen, and bone marrow. Although these results cannot be extrapolated to humans, this work highlights the importance of developing ultrasensitive methods for assessing the behavior of nanoparticles in animals. It has been published in the journal ACS Nano (“Carbon Nanotube Translocation to Distant Organs after Pulmonary Exposure: Insights from in Situ 14C-Radiolabeling and Tissue Radioimaging”).

A July 1, 2014 CNRS [France Centre national de la recherche scientifique] press release, which originated the news item, describes both applications for carbon nanotubes and the experiment in greater detail,

Carbon nanotubes are highly specific nanoparticles with outstanding mechanical and electronic properties that make them suitable for use in a wide range of applications, from structural materials to certain electronic components. Their many present and future uses explain why research teams around the world are now focusing on their impact on human health and the environment.

Researchers from CEA and the CNRS joined forces to study the distribution over time of these nanoparticles in mice, following contamination by inhalation. They combined radiolabeling with radio imaging tools for optimum detection sensitivity. When making the carbon nanotubes, stable carbon (12C) atoms were replaced directly by radioactive carbon (14C) atoms in the very structure of the tubes. This method allows the use of carbon nanotubes similar to those produced in industry, but labeled with 14C. Radio imaging tools make it possible to detect up to twenty or so carbon nanotubes on an animal tissue sample.

A single dose of 20 µg [micrograms] of labeled nanotubes was administered at the start of the protocol, then monitored for one year. The carbon nanotubes were observed to translocate from the lungs to other organs, especially the liver, spleen, and bone marrow. The study demonstrates that these nanoparticles are capable of crossing the pulmonary epithelial barrier, or air-blood barrier. It was also observed that the quantity of carbon nanotubes in these organs rose steadily over time, thus demonstrating that these particles are not eliminated on this timescale. Further studies will have to determine whether this observation remains true beyond a year.

The CEA [French Alternative Energies and Atomic Energy Commission {Commissariat à l’énergie atomique et aux énergies alternatives}] and CNRS teams have developed highly specific skills that enable them to study the health and environmental impact of nanoparticles from various angles. Nanotoxicology and nanoecotoxicology research such as this is both a priority for society and a scientific challenge, involving experimental approaches and still emerging concepts.

This work is conducted as part of CEA’s interdisciplinary Toxicology and Nanosciences programs. These are management, coordination and support structures set up to promote multidisciplinary approaches for studying the potential impact on living organisms of various components of industrial interest, including heavy metals, radionuclides, and new products.

At the CNRS, these concerns are reflected in particular in major initiatives such as the International Consortium for the Environmental Implications of Nano Technology (i-CEINT), a CNRS-led international initiative focusing on the ecotoxicology of nanoparticles. CNRS teams also have a long tradition of close involvement in matters relating to standards and regulations. Examples of this include the ANR NanoNORMA program, led by the CNRS, or ongoing work within the French C’Nano network.

For those who would either prefer or like to check out  the French language version of the July 1, 2014 CNRS press release (La biodistribution des nanotubes de carbone dans l’organisme), it can be found here.

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

Carbon Nanotube Translocation to Distant Organs after Pulmonary Exposure: Insights from in Situ 14C-Radiolabeling and Tissue Radioimaging by Bertrand Czarny, Dominique Georgin, Fannely Berthon, Gael Plastow, Mathieu Pinault, Gilles Patriarche, Aurélie Thuleau, Martine Mayne L’Hermite, Frédéric Taran, and Vincent Dive. ACS Nano, 2014, 8 (6), pp 5715–5724 DOI: 10.1021/nn500475u Publication Date (Web): May 22, 2014

Copyright © 2014 American Chemical Society

This paper is behind a paywall.

European NanoSafety Cluster issues 2014 compendium of projects

A June 16, 2014 news item on Nanowerk profiles a recently published compendium of projects from the European NanoSafety Cluster (Note:  A link has been removed),

The EU NanoSafety Cluster is an initiative to maximise the synergies between the existing FP6 and FP7 projects addressing all aspects of nanosafety including toxicology, ecotoxicology, exposure assessment, mechanisms of interaction, risk assessment and standardisation.

About fifty projects are either completed or running and represent a total RTD investment of €137M, from the NMP and other programmes, under FP6 (13 projects, €31M) and FP7 (34 projects, €106M). [FP 6 and FP 7 are the Sixth Framework Programme and /seventh Framework, respectively; European Union-wide science funding programmes,the Horizon 2020 funding project supersedes FP 7]

These projects together with a significant number of projects supported by government resources in the EU member states and the FP7 associated states, and other projects addressing safety as side objective, represent the valuable efforts of the scientific and industrial research community for progress.

Here’s a description of the compendium from p. 5 of the PDF version of the Compendium of Projects in the European NanoSafety Cluster 2014 Edition,

This is the fourth edition of the Nanosafety Cluster compendium. It documents the status of important EU-funded projects on nanomaterial toxicity and exposure monitoring, integrated risk management, research infrastructure and coordination and support activities as well as regulatory-focussed research on nanosafety.

The compendium is not intended to be a guidance document for human health and environmental safety management of nanotechnologies, as such guidance documents already exist and are widely available.

Neither is the compendium intended to be a medium for the publication of scientific data and research results, as this task is covered by scientific conferences and the peer reviewed press.

The compendium aims to showcase the exciting and important European-wide collaborative research being undertaken to ensure the safe implementation of nanotechnologies, and to act as a one-stop-shop for all stakeholders interested in acquiring an overview of current research activities.This years’ compendium contains information on 30 running (or very recently finished) projects, including new entries describing the projects resulting from the last call of FP7, including eNanoMapper, NanoDefine and FutureNanoNeeds. …

What a good idea! I wonder if there’s an equivalent for the international scene?

DNA damage from engineered nanoparticles (zinc oxide, silver, silicon dioxide, cerium oxide and iron oxide)

Before launching into this research, there are a few provisos. This work was done in a laboratory, a highly specialized environment that does not mimic real-life conditions, and performed on animal cells (a hamster’s). As well, naturally occurring nanoparticles were not included (my Nov. 24, 2011 post has some information about naturally occurring nanomaterials including nanosilver which we have been ingesting for centuries).

That said, the studies from the Massachusetts Institute of Techology (MIT) and the Harvard School of Public Health (HSPH; last mentioned here in an April 2, 2014 post) are concerning (from an April 9, 2014 news item on Azonano).

A new study from MIT and the Harvard School of Public Health (HSPH) suggests that certain nanoparticles can also harm DNA. This research was led by Bevin Engelward, a professor of biological engineering at MIT, and associate professor Philip Demokritou, director of HSPH’s Center for Nanotechnology and Nanotoxicology.

The researchers found that zinc oxide nanoparticles, often used in sunscreen to block ultraviolet rays, significantly damage DNA. Nanoscale silver, which has been added to toys, toothpaste, clothing, and other products for its antimicrobial properties, also produces substantial DNA damage, they found.

The findings, published in a recent issue of the journal ACS Nano, relied on a high-speed screening technology to analyze DNA damage. This approach makes it possible to study nanoparticles’ potential hazards at a much faster rate and larger scale than previously possible.

More details about current testing requirements and the specific nanoparticles studied can be found in the April 8, 2014 MIT news release, which originated the news item,

The Food and Drug Administration does not require manufacturers to test nanoscale additives for a given material if the bulk material has already been shown to be safe. However, there is evidence that the nanoparticle form of some of these materials may be unsafe: Due to their immensely small size, these materials may exhibit different physical, chemical, and biological properties, and penetrate cells more easily.

“The problem is that if a nanoparticle is made out of something that’s deemed a safe material, it’s typically considered safe. There are people out there who are concerned, but it’s a tough battle because once these things go into production, it’s very hard to undo,” Engelward says.

The researchers focused on five types of engineered nanoparticles — silver, zinc oxide, iron oxide, cerium oxide, and silicon dioxide (also known as amorphous silica) — that are used industrially. Some of these nanomaterials can produce free radicals called reactive oxygen species, which can alter DNA. Once these particles get into the body, they may accumulate in tissues, causing more damage.

“It’s essential to monitor and evaluate the toxicity or the hazards that these materials may possess. There are so many variations of these materials, in different sizes and shapes, and they’re being incorporated into so many products,” says Christa Watson, a postdoc at HSPH and the paper’s lead author. “This toxicological screening platform gives us a standardized method to assess the engineered nanomaterials that are being developed and used at present.”

The researchers hope that this screening technology could also be used to help design safer forms of nanoparticles; they are already working with partners in industry to engineer safer UV-blocking nanoparticles. Demokritou’s lab recently showed that coating zinc oxide particles with a nanothin layer of amorphous silica can reduce the particles’ ability to damage DNA.

Given that Demokritou was part of a team that recently announced a new testing platform (Volumetric Centrifugation Method [VCM]) for nanoparticles as mentioned in my April 2, 2014 post, I was a little curious about the  platform for this project ( the CometChip) and, as always, curious about the results for all the tested engineered nanoparticles (Note: A link has been removed), from the news release,

Until now, most studies of nanoparticle toxicity have focused on cell survival after exposure. Very few have examined genotoxicity, or the ability to damage DNA — a phenomenon that may not necessarily kill a cell, but one that can lead to cancerous mutations if the damage is not repaired.

A common way to study DNA damage in cells is the so-called “comet assay,” named for the comet-shaped smear that damaged DNA forms during the test. The procedure is based on gel electrophoresis, a test in which an electric field is applied to DNA placed in a matrix, forcing the DNA to move across the gel. During electrophoresis, damaged DNA travels farther than undamaged DNA, producing a comet-tail shape.

Measuring how far the DNA can travel reveals how much DNA damage has occurred. This procedure is very sensitive, but also very tedious.

In 2010, Engelward and MIT professor Sangeeta Bhatia developed a much more rapid version of the comet assay, known as the CometChip. Using microfabrication technology, single cells can be trapped in tiny microwells within the matrix. This approach makes it possible to process as many as 1,000 samples in the time that it used to take to process just 30 samples — allowing researchers to test dozens of experimental conditions at a time, which can be analyzed using imaging software.

Wolfgang Kreyling, an epidemiologist at the German Research Center for Environmental Health who was not involved in the study, says this technology should help toxicologists catch up to the rapid rate of deployment of engineered nanoparticles (ENPs).

“High-throughput screening platforms are desperately needed,” Kreyling says. “The proposed approach will be not only an important tool for nanotoxicologists developing high-throughput screening strategies for the assessment of possible adverse health effects associated with ENPs, but also of great importance for material scientists working on the development of novel ENPs and safer-by-design approaches.”

Using the CometChip, the MIT and HSPH researchers tested the nanoparticles’ effects on two types of cells that are commonly used for toxicity studies: a type of human blood cells called lymphoblastoids, and an immortalized line of Chinese hamster ovary cells.

Zinc oxide and silver produced the greatest DNA damage in both cell lines. At a concentration of 10 micrograms per milliliter — a dose not high enough to kill all of the cells — these generated a large number of single-stranded DNA breaks.

Silicon dioxide, which is commonly added during food and drug production, generated very low levels of DNA damage. Iron oxide and cerium oxide also showed low genotoxicity.

Happily the researchers are taking a pragmatic approach to the results (from the news release),

More studies are needed to determine how much exposure to metal oxide nanoparticles could be unsafe for humans, the researchers say.

“The biggest challenge we have as people concerned with exposure biology is deciding when is something dangerous and when is it not, based on the dose level. At low levels, probably these things are fine,” Engelward says. “The question is: At what level does it become problematic, and how long will it take for us to notice?”

One of the areas of greatest concern is occupational exposure to nanoparticles, the researchers say. Children and fetuses are also potentially at greater risk because their cells divide more often, making them more vulnerable to DNA damage.

The most common routes that engineered nanoparticles follow into the body are through the skin, lungs, and stomach, so the researchers are now investigating nanoparticle genotoxicity on those cell types. They are also studying the effects of other engineered nanoparticles, including metal oxides used in printer and photocopier toner, which can become airborne and enter the lungs.

Kudos to the writer for the clarity and care shown here (I think it’s Anne Trafton but MIT is not including bylines as it did previously, so I’m uncertain).

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

High-Throughput Screening Platform for Engineered Nanoparticle-Mediated Genotoxicity Using CometChip Technology by Christa Watson, Jing Ge, Joel Cohen, Georgios Pyrgiotakis, Bevin P. Engelward, and Philip Demokritou. ACS Nano, 2014, 8 (3), pp 2118–2133 DOI: 10.1021/nn404871p Publication Date (Web): March 11, 2014
Copyright © 2014 American Chemical Society

This article is behind a paywall.