Tag Archives: Brazil

‘Nano to go’, a practical guide to safe handling of nanomaterials and other innovative materials in the workplace

If you’ve been looking for a practical guide to handling nanomaterials you may find that nanoToGo fills the bill. From an Oct. 23, 2015 posting by Lynn Bergeson for Nanotechnology Now,

In September 2015, “Nano to go!” was published. See http://nanovalid.eu/index.php/nanovalid-publications/306-nanotogo “Nano to go!” is “a practically oriented guidance on safe handling of nanomaterials and other innovative materials at the workplace.” The German Federal Institute for Occupational Health (BAuA) developed it within the NanoValid project.

From the nanoToGo webpage on the NanoValid project website (Note: Links have been removed),

Nano to go! contains a brochure, field studies, presentations and general documents to comprehensively support risk assessment and risk management. …

Brochure →

The brochure Safe handling of nanomaterials and other advanced materials at workplacessupports risk assessment and risk management when working with nanomaterials. It provides safety strategies and protection measures for handling nanomaterials bound in solid matrices, dissolved in liquids, insoluble or insoluble powder form, and for handling nanofibres. Additional recommendations are given for storage and disposal of nanomaterials, for protection from fire and explosion, for training and instruction courses, and for occupational health.

Field Studies→

The field studies comprise practical examples of expert assessment of safety and health at different workplaces. They contain detailed descriptions of several exposure measurements at pilot plants and laboratories. The reports describe methods, sampling strategies and devices, summarise and discuss results, and combine measurements and non-measurement methods.

General →

Useful information, templates and examples, such as operating instructions, a sampling protocol, a dialogue guide and a short introduction to safety management and nanomaterials.

Presentations →

Ready to use presentations for university lecturers, supervisors and instruction courses, complemented with explanatory notes.

The ‘brochure’ is 56 pages; I would have called it a manual.

As for the NanoValid project, there’s this from the project’s homepage,

The EU FP7 [Framework Programme 7] large-scale integrating project NanoValid (contract: 263147) has been launched on the 1st of November 2011, as one of the “flagship” nanosafety projects. The project consists of 24 European partners from 14 different countries and 6 partners from Brazil, Canada, India and the US and will run from 2011 to 2015, with a total budget of more than 13 mio EUR (EC contribution 9.6 mio EUR). Main objective of NanoValid is to develop a set of reliable reference methods and materials for the fabrication, physicochemical (pc) characterization, hazard identification and exposure assessment of engineered nanomaterials (EN), including methods for dispersion control and labelling of ENs. Based on newly established reference methods, current approaches and strategies for risk and life cycle assessment will be improved, modified and further developed, and their feasibility assessed by means of practical case studies.

I was not expecting to see Canada in there.

At the root of nanotechnology: advances in dentistry

I couldn’t resist the dental wordplay in my headline. Strictly speaking this posting features a research paper that is looking into dentistry’s nanotechnology-enabled future. From an Oct. 19, 2015 news item on phys.org,

Have a cavity? Ask your dentist about filling it with a mixture of nanoparticles including silica and zirconia. These white fillings (known as nano-composite resins) resemble teeth better than their metal alternatives and are less likely to come loose or fracture teeth. This is just the beginning argue Brazilian scientists in a review of “nanodentistry,” published October 19 [2015] in Trends in Biotechnology. Next-generation dental materials incorporating nanotechnology aim to help teeth self-heal, rebuild enamel, and protect against bacterial infections.

An Oct. 19, 2015 Cell Press news release on EurekAlert, which originated the news item, expands on the theme,

“Nanotechnology can be faced sometimes as a paradigm that promised a lot and delivered very little,” says senior author Nelson Durán of the Universidade Estadual de Campinas. “The evolution of dental materials though nanotechnology is real and remarkable, reflecting on a billionaire market. In this way, dentistry was in fact one of the most benefited areas from the development of nanotechnology.”

Since the introduction of nano-composite resins a decade ago, engineers have been exploring how else nanotechnology can safely be used in the dentist’s office. Products could include antimicrobial adhesives made up of carbon nanotubes–creating a kind of wearable toothpaste–or quantum dots combined with cancer-specific antibodies that can be applied inside the mouth, emitting light if they detect any troublesome cells.

“The remineralization of enamel and dentin with the use of nanoparticles (incorporated in different vehicles), a key issue for improving the quality and longevity of resin restorations, is being currently investigated,” says co-author Amauri Jardim de Paula of Universidade Federal do Ceará. “A future perspective is that nanoparticles incorporated in dental materials will prevent and/or control oral diseases through their long-term release and action.”

Although nanodental technologies have evolved quickly, safety and cost will be barriers to getting them on the market. Some nanomaterials might be toxic to healthy cells, so any new nanomaterials to be used for dentistry would need formal pre-clinical and clinical trials before they can receive approval. Patients will also need to be told that a treatment will use materials in the nanometer size range and should be aware of any possible side effects. This new technology could also be expensive, and insurance companies may not want to foot the bill if treatments could be considered cosmetic; composite resins, for example, are still an out-of-pocket cost.

The review authors believe these hurdles can be overcome, however, and that new nanodental products should be available within a few years.

The research has been illustrated,

Caption: This schematic represents the current use and perspectives on the use of nanomaterials on therapeutic dentistry. Credit: Padovania et al./Trends in Biotechnology 2015

Caption: This schematic represents the current use and perspectives on the use of nanomaterials on therapeutic dentistry.
Credit: Padovania et al./Trends in Biotechnology 2015

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

Advances in Dental Materials through Nanotechnology: Facts, Perspectives and Toxicological Aspects by Gislaine C. Padovani, Victor P. Feitosa, Salvatore Sauro, Franklin R. Tay, Gabriela Durán, Amauri J. Paula, & Nelson Durán. Trends in Biotechnology – Cell DOI: http://dx.doi.org/10.1016/j.tibtech.2015.09.005 Publication stage: In Press Corrected Proof Published online Oct. 19, 2015

The paper appears to be open access.

Brazilian scientists and an anti-clumping strategy for nanoparticles

An Oct. 16, 2015 Springer press release (also on EurekAlert) explains why nanoparticle clumping is a problem and presents the proposed solution,

Nanoparticles are ubiquitous in industrial applications ranging from drug delivery and biomedical diagnostics to developing hydrophobic surfaces, lubricant additives and enhanced oil recovery solutions in petroleum fields. For such nanoparticles to be effective, they need to remain well dispersed into the fluid surrounding them. In a study published in EPJ B, Brazilian physicists identified the conditions that lead to instability of nanoparticles and producing aggregates. This happens when the electric force on their surface no longer balances by the sum of the attractive or repulsive forces between nanoparticles. These findings were recently published by Lucas de Lara from the Centre for Natural and Human Sciences, at the University Federal of ABC (UFABC) in Santo André, SP, Brazil and colleagues.

The authors studied silica nanoparticles that do not react with their surroundings in a solution containing two types of salts, table salt and calcium chloride. They then attached an ending to the nanoparticles, a process called functionalisation. Featuring endings that are hydrophilic or hydrophobic can help nanoparticles remain dispersed.

They then varied the temperature and salt concentration and monitored the ion dispersion in the salty solution. In some cases, they observed the accumulation of ions around nanoparticles, leading to the formation of an electric double-layer around the nanoparticles in otherwise overall electrically neutral nanoparticle suspensions.

De Lara and colleagues then determined the factor influencing the stability of such nanoparticles in solutions. Their simulations suggest that the instability of functionalised nanoparticles dispersion in brine depends on several factors preceding their aggregation. The “culprits” include the formation of an electric double layer – observed to be greater for calcium chloride than for table salt – and the narrowing of that double layer. In addition, the considerable variation in the interface tension followed by a steep increase in ion mobility also contribute to instability. The group’s findings on overall neutral nanoparticles are in line with previous work with electrically charged nanoparticles.

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

The stability and interfacial properties of functionalized silica nanoparticles dispersed in brine studied by molecular dynamics by Lucas S. de Lara, Vagner A. Rigo, and Caetano R. Miranda. Eur. Phys. J. B (2015) 88: 261
http://dx.doi.org/10.1140/epjb/e2015-60543-1 Published online: 14 October 2015

This paper is behind a paywall.

Global overview of nano-enabled food and agriculture regulation

First off, this post features an open access paper summarizing global regulation of nanotechnology in agriculture and food production. From a Sept. 11, 2015 news item on Nanowerk,

An overview of regulatory solutions worldwide on the use of nanotechnology in food and feed production shows a differing approach: only the EU and Switzerland have nano-specific provisions incorporated in existing legislation, whereas other countries count on non-legally binding guidance and standards for industry. Collaboration among countries across the globe is required to share information and ensure protection for people and the environment, according to the paper …

A Sept. 11, 2015 European Commission Joint Research Centre press release (also on EurekAlert*), which originated the news item, summarizes the paper in more detail (Note: Links have been removed),

The paper “Regulatory aspects of nanotechnology in the agri/feed/food sector in EU and non-EU countries” reviews how potential risks or the safety of nanotechnology are managed in different countries around the world and recognises that this may have implication on the international market of nano-enabled agricultural and food products.

Nanotechnology offers substantial prospects for the development of innovative products and applications in many industrial sectors, including agricultural production, animal feed and treatment, food processing and food contact materials. While some applications are already marketed, many other nano-enabled products are currently under research and development, and may enter the market in the near future. Expected benefits of such products include increased efficacy of agrochemicals through nano-encapsulation, enhanced bioavailability of nutrients or more secure packaging material through microbial nanoparticles.

As with any other regulated product, applicants applying for market approval have to demonstrate the safe use of such new products without posing undue safety risks to the consumer and the environment. Some countries have been more active than others in examining the appropriateness of their regulatory frameworks for dealing with the safety of nanotechnologies. As a consequence, different approaches have been adopted in regulating nano-based products in the agri/feed/food sector.

The analysis shows that the EU along with Switzerland are the only ones which have introduced binding nanomaterial definitions and/or specific provisions for some nanotechnology applications. An example would be the EU labelling requirements for food ingredients in the form of ‘engineered nanomaterials’. Other regions in the world regulate nanomaterials more implicitly mainly by building on non-legally binding guidance and standards for industry.

The overview of existing legislation and guidances published as an open access article in the Journal Regulatory Toxicology and Pharmacology is based on information gathered by the JRC, RIKILT-Wageningen and the European Food Safety Agency (EFSA) through literature research and a dedicated survey.

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

Regulatory aspects of nanotechnology in the agri/feed/food sector in EU and non-EU countries by Valeria Amenta, Karin Aschberger, , Maria Arena, Hans Bouwmeester, Filipa Botelho Moniz, Puck Brandhoff, Stefania Gottardo, Hans J.P. Marvin, Agnieszka Mech, Laia Quiros Pesudo, Hubert Rauscher, Reinhilde Schoonjans, Maria Vittoria Vettori, Stefan Weigel, Ruud J. Peters. Regulatory Toxicology and Pharmacology Volume 73, Issue 1, October 2015, Pages 463–476 doi:10.1016/j.yrtph.2015.06.016

This is the most inclusive overview I’ve seen yet. The authors cover Asian countries, South America, Africa, and the MIddle East, as well as, the usual suspects in Europe and North America.

Given I’m a Canadian blogger I feel obliged to include their summary of the Canadian situation (Note: Links have been removed),

4.2. Canada

The Canadian Food Inspection Agency (CFIA) and Public Health Agency of Canada (PHAC), who have recently joined the Health Portfolio of Health Canada, are responsible for food regulation in Canada. No specific regulation for nanotechnology-based food products is available but such products are regulated under the existing legislative and regulatory frameworks.11 In October 2011 Health Canada published a “Policy Statement on Health Canada’s Working Definition for Nanomaterials” (Health Canada, 2011), the document provides a (working) definition of NM which is focused, similarly to the US definition, on the nanoscale dimensions, or on the nanoscale properties/phenomena of the material (see Annex I). For what concerns general chemicals regulation in Canada, the New Substances (NS) program must ensure that new substances, including substances that are at the nano-scale (i.e. NMs), are assessed in order to determine their toxicological profile ( Environment Canada, 2014). The approach applied involves a pre-manufacture and pre-import notification and assessment process. In 2014, the New Substances program published a guidance aimed at increasing clarity on which NMs are subject to assessment in Canada ( Environment Canada, 2014).

Canadian and US regulatory agencies are working towards harmonising the regulatory approaches for NMs under the US-Canada Regulatory Cooperation Council (RCC) Nanotechnology Initiative.12 Canada and the US recently published a Joint Forward Plan where findings and lessons learnt from the RCC Nanotechnology Initiative are discussed (Canada–United States Regulatory Cooperation Council (RCC) 2014).

Based on their summary of the Canadian situation, with which I am familiar, they’ve done a good job of summarizing. Here are a few of the countries whose regulatory instruments have not been mentioned here before (Note: Links have been removed),

In Turkey a national or regional policy for the responsible development of nanotechnology is under development (OECD, 2013b). Nanotechnology is considered as a strategic technological field and at present 32 nanotechnology research centres are working in this field. Turkey participates as an observer in the EFSA Nano Network (Section 3.6) along with other EU candidate countries Former Yugoslav Republic of Macedonia, and Montenegro (EFSA, 2012). The Inventory and Control of Chemicals Regulation entered into force in Turkey in 2008, which represents a scale-down version of the REACH Regulation (Bergeson et al. 2010). Moreover, the Ministry of Environment and Urban Planning published a Turkish version of CLP Regulation (known as SEA in Turkish) to enter into force as of 1st June 2016 (Intertek).

The Russian legislation on food safety is based on regulatory documents such as the Sanitary Rules and Regulations (“SanPiN”), but also on national standards (known as “GOST”) and technical regulations (Office of Agricultural Affairs of the USDA, 2009). The Russian policy on nanotechnology in the industrial sector has been defined in some national programmes (e.g. Nanotechnology Industry Development Program) and a Russian Corporation of Nanotechnologies was established in 2007.15 As reported by FAO/WHO (FAO/WHO, 2013), 17 documents which deal with the risk assessment of NMs in the food sector were released within such federal programs. Safe reference levels on nanoparticles impact on the human body were developed and implemented in the sanitary regulation for the nanoforms of silver and titanium dioxide and, single wall carbon nanotubes (FAO/WHO, 2013).

Other countries included in this overview are Brazil, India, Japan, China, Malaysia, Iran, Thailand, Taiwan, Australia, New Zealand, US, South Africa, South Korea, Switzerland, and the countries of the European Union.

*EurekAlert link added Sept. 14, 2015.

Brazilian company encapsulates silver nanoparticles in milk packaging for longer product life

They’ve managed to double the shelf life for fresh milk from seven days to 15 be encapsulating silver nanoparticles in ceramic microparticles in packaging for fresh milk. From an Aug. 4, 2015 news item on Nanowerk,

Agrindus, an agribusiness company located in São Carlos, São Paulo state, Brazil, has increased the shelf life of grade A pasteurized fresh whole milk from seven to 15 days.

This feat was achieved by incorporating silver-based microparticles with bactericidal, antimicrobial and self-sterilizing properties into the rigid plastic bottles used as packaging for the milk.

The technology was developed by Nanox, also located in São Carlos. Supported by FAPESP’s Innovative Research in Small Business (PIPE) program, the nanotechnology company is a spinoff from the Center for Research and Development of Functional Materials (CDFM), one of the Research, Innovation and Dissemination Centers (RIDCs) supported by São Paulo Research Foundation (FAPESP).

“We already knew use of our antimicrobial and bactericidal material in rigid or flexible plastic food packaging improves conservation and extends shelf life. So we decided to test it in the polyethylene used to bottle grade A fresh milk in Brazil. The result was that we more than doubled the product’s shelf life solely by adding the material to the packaging, without mixing any additives with the milk”, said the Nanox CEO, Luiz Pagotto Simões.

An Aug. 4, 2015 Fundação de Amparo à Pesquisa do Estado de São Paulo news release on EurekAlert, which originated the news item, expands on the theme,

According to Simões, the microparticles are included as a powder in the polyethylene preform that is used to make plastic bottles by blow or injection molding. The microparticles are inert, so there is no risk of their detaching from the packaging and coming into contact with the milk.

Tests of the material’s effectiveness in extending the shelf life of fresh milk were performed for a year by Agrindus, Nanox and independent laboratories. “Only after shelf life extension had been certified did we decide to bring the material to market,” Simões said.

In addition to Agrindus, the material is also being tested by two other dairies that distribute fresh milk in plastic bottles in São Paulo and Minas Gerais and by dairies in the Brazilian southern region that sell fresh milk in flexible plastic packaging.

“In milk bags, the material is capable of extending shelf life from four to ten days,” he said.

Nanox plans to market the product in Europe and the United States, where much larger volumes of fresh milk are consumed than in Brazil.

The kind of milk most consumed in Brazil is ultra-high temperature (UHT), or “long life” milk, which is sterilized at temperatures ranging from 130°C to 150°C for two to four seconds to kill most of the bacterial spores. Unopened UHT milk has a shelf life of up to four months at room temperature.

Whole milk, known as grade A in Brazil, is pasteurized at much lower temperatures by the farmer and requires refrigeration. “Doubling the shelf life of whole milk translates into significant benefits in terms of logistics, storage, quality and food safety,” Simões said.

Countless applications

The silver-based microparticles developed by Nanox are currently being used in several other products other than packaging for fresh milk, including plastic utensils, PVC film for wrapping food, toilet seats, shoe insoles, hair dryers and flatirons, paints, resins, and ceramics, as well as coatings for medical and dental instruments such as grippers, drills and scalpels.

But the company’s largest markets today are makers of rugs, carpets, and white goods, such as refrigerators, drinking fountains and air conditioners.

“We’ve supplied several products to white goods manufacturers since 2007,” Simões said. “This material is shipped to the leading players in the market.” Nanox currently exports the product to 12 countries via local distributors in Chile, China, Colombia, Italy, Mexico and Japan, among others.

The company now wants to enter the United States, having won approval in 2013 from the Food & Drug Administration (FDA) to market the bactericidal material for use in food packaging.

“We’ve applied for clearance by the EPA [the Environmental Protection Agency] so that we can sell to a larger proportion of the US market,” Simões said.

Neither Brazil nor the US has clear legislation on the use of particles at the nanometer scale [a billionth of a meter] in products that involve contact with food, so the company uses nanotechnology processes that result in silver-based particles at the micrometer scale [a millionth of a meter], he said.

The core of the technology consists of coating ceramic particles made of silica with silver nanoparticles. The silver nanoparticles bond with the ceramic matrix to form a micrometre scale composite with bactericidal properties.

“The combination of silver particles with a ceramic matrix produces synergistic effects. Silver has bactericidal properties, and while silica doesn’t, it boosts those of the silver and helps control the release of silver particles to kill bacteria,” he said.

I wonder if they’ve done any ‘life cycle’ analysis. In other words, what happens to the packaging and those encapsulated silver nanoparticles when the milk jugs (and Nanox’s other silver-based products) are recycled or put in the garbage dump?

You can find out more about Nanox (English language version) here and about Agrindus, a division of Letti?, (you will need Portuguese language reading skills) here.

US Navy and its science diplomacy efforts

I gather the US military has decided to adopt something they call science diplomacy . A July 30, 2015 US Navy news release on EurekAlert describes the latest effort,

Scientific diplomacy took a giant step forward July 24 as Chief of Naval Research (CNR) Rear Adm. Mat Winter officially opened the new Office of Naval Research Global (ONR Global) office in Sao Paulo, Brazil.

ONR Global-charged with providing international science and technology (S&T) solutions for current and future naval challenges-engages with the international S&T community around the world. Officials note the new office in Brazil will be critical to the advancement of open-source, unclassified knowledge and collaboration in a region marked by rapidly-expanding economies and significant growth in cutting-edge science.

“The opening of the Sao Paulo office reflects the strong, longstanding S&T relationships ONR has with the international community,” Winter noted. “This office will serve as a regional hub for collaboration with researchers across South America to share discovery and invention, which are the lifeblood of scientific advancement.”

Present at the event were governmental representatives from both the U.S. and Brazil. Members of the academic community were also in attendance at the official opening celebration-some of whom may be involved in the many future S&T-related exchanges and more that will be sponsored by ONR Global as part of the new office’s mission.

Recent collaborative research between South American and U.S. scientists includes academic gatherings in the fields of alternative energy, underwater acoustics, augmented reality and more, as well as research projects involving topics ranging from flood prediction to materials stress and marine genomics.

The new office will help coordinate activities across the vast South American continent with ONR Global’s existing office in Santiago, Chile.

Capt. Clark Troyer, ONR Global’s commanding officer, noted that the new Brazil hub is expected to deliver significant positive impacts for the future force.

“The opening of a new office in the largest country in South America is an important development, emphasizing that breakthrough science and technology capabilities generally come about only through collaboration and partnerships,” he said. “Those who follow S&T from a naval perspective recognize that Brazil is significant both in its impressive academic and research communities, as well as the wealth of opportunities to conduct research in unique ecological settings.”

ONR Global has offices on multiple continents, including Asia, Europe, North America and South America. Its commanding officer and technical director are based in London. An important part of the command’s collaborative efforts are associate directors, who promote collaboration with international scientists; and science advisors, who identify fleet needs.

Both groups serve as the CNR’s “science ambassadors,” creating essential links with both the international S&T community and operational forces to successfully execute the Naval S&T Strategy.

As I hinted earlier this isn’t the first US military science diplomacy effort I’ve stumbled across. A July 30, 2015 posting titled. Science diplomacy: high school age Pakistani students (terror attack survivors) attend NanoDiscovery Institute in New York State features a US military presence,

The students will also visit West Point to see the similarities and differences with their military school back home.

To finish up the trip, the students will present their final nanotech projects to SUNY Poly staff, and will fly back to Washington to present the projects to U.S. military officials. [emphasis mine]

Of course, it makes sense that students at an army school in Pakistan might want to see West Point. As for showing their nano projects to US military officials, that’s somewhat understandable.

I guess it’s a question of timing but it seems odd that two military-oriented science diplomacy efforts are being featured in the news in a relatively short space of time. Is the US military gearing up its science diplomacy efforts? And, what does science diplomacy really mean to the US military?

Nanomaterials and UV (ultraviolet) light for environmental cleanups

I think this is the first time I’ve seen anything about a technology that removes toxic materials from both water and soil; it’s usually one or the other. A July 22, 2015 news item on Nanowerk makes the announcement (Note: A link has been removed),

Many human-made pollutants in the environment resist degradation through natural processes, and disrupt hormonal and other systems in mammals and other animals. Removing these toxic materials — which include pesticides and endocrine disruptors such as bisphenol A (BPA) — with existing methods is often expensive and time-consuming.

In a new paper published this week in Nature Communications (“Nanoparticles with photoinduced precipitation for the extraction of pollutants from water and soil”), researchers from MIT [Massachusetts Institute of Technology] and the Federal University of Goiás in Brazil demonstrate a novel method for using nanoparticles and ultraviolet (UV) light to quickly isolate and extract a variety of contaminants from soil and water.

A July 21, 2015 MIT news release by Jonathan Mingle, which originated the news item, describes the inspiration and the research in more detail,

Ferdinand Brandl and Nicolas Bertrand, the two lead authors, are former postdocs in the laboratory of Robert Langer, the David H. Koch Institute Professor at MIT’s Koch Institute for Integrative Cancer Research. (Eliana Martins Lima, of the Federal University of Goiás, is the other co-author.) Both Brandl and Bertrand are trained as pharmacists, and describe their discovery as a happy accident: They initially sought to develop nanoparticles that could be used to deliver drugs to cancer cells.

Brandl had previously synthesized polymers that could be cleaved apart by exposure to UV light. But he and Bertrand came to question their suitability for drug delivery, since UV light can be damaging to tissue and cells, and doesn’t penetrate through the skin. When they learned that UV light was used to disinfect water in certain treatment plants, they began to ask a different question.

“We thought if they are already using UV light, maybe they could use our particles as well,” Brandl says. “Then we came up with the idea to use our particles to remove toxic chemicals, pollutants, or hormones from water, because we saw that the particles aggregate once you irradiate them with UV light.”

A trap for ‘water-fearing’ pollution

The researchers synthesized polymers from polyethylene glycol, a widely used compound found in laxatives, toothpaste, and eye drops and approved by the Food and Drug Administration as a food additive, and polylactic acid, a biodegradable plastic used in compostable cups and glassware.

Nanoparticles made from these polymers have a hydrophobic core and a hydrophilic shell. Due to molecular-scale forces, in a solution hydrophobic pollutant molecules move toward the hydrophobic nanoparticles, and adsorb onto their surface, where they effectively become “trapped.” This same phenomenon is at work when spaghetti sauce stains the surface of plastic containers, turning them red: In that case, both the plastic and the oil-based sauce are hydrophobic and interact together.

If left alone, these nanomaterials would remain suspended and dispersed evenly in water. But when exposed to UV light, the stabilizing outer shell of the particles is shed, and — now “enriched” by the pollutants — they form larger aggregates that can then be removed through filtration, sedimentation, or other methods.

The researchers used the method to extract phthalates, hormone-disrupting chemicals used to soften plastics, from wastewater; BPA, another endocrine-disrupting synthetic compound widely used in plastic bottles and other resinous consumer goods, from thermal printing paper samples; and polycyclic aromatic hydrocarbons, carcinogenic compounds formed from incomplete combustion of fuels, from contaminated soil.

The process is irreversible and the polymers are biodegradable, minimizing the risks of leaving toxic secondary products to persist in, say, a body of water. “Once they switch to this macro situation where they’re big clumps,” Bertrand says, “you won’t be able to bring them back to the nano state again.”

The fundamental breakthrough, according to the researchers, was confirming that small molecules do indeed adsorb passively onto the surface of nanoparticles.

“To the best of our knowledge, it is the first time that the interactions of small molecules with pre-formed nanoparticles can be directly measured,” they write in Nature Communications.

Nano cleansing

Even more exciting, they say, is the wide range of potential uses, from environmental remediation to medical analysis.

The polymers are synthesized at room temperature, and don’t need to be specially prepared to target specific compounds; they are broadly applicable to all kinds of hydrophobic chemicals and molecules.

“The interactions we exploit to remove the pollutants are non-specific,” Brandl says. “We can remove hormones, BPA, and pesticides that are all present in the same sample, and we can do this in one step.”

And the nanoparticles’ high surface-area-to-volume ratio means that only a small amount is needed to remove a relatively large quantity of pollutants. The technique could thus offer potential for the cost-effective cleanup of contaminated water and soil on a wider scale.

“From the applied perspective, we showed in a system that the adsorption of small molecules on the surface of the nanoparticles can be used for extraction of any kind,” Bertrand says. “It opens the door for many other applications down the line.”

This approach could possibly be further developed, he speculates, to replace the widespread use of organic solvents for everything from decaffeinating coffee to making paint thinners. Bertrand cites DDT, banned for use as a pesticide in the U.S. since 1972 but still widely used in other parts of the world, as another example of a persistent pollutant that could potentially be remediated using these nanomaterials. “And for analytical applications where you don’t need as much volume to purify or concentrate, this might be interesting,” Bertrand says, offering the example of a cheap testing kit for urine analysis of medical patients.

The study also suggests the broader potential for adapting nanoscale drug-delivery techniques developed for use in environmental remediation.

“That we can apply some of the highly sophisticated, high-precision tools developed for the pharmaceutical industry, and now look at the use of these technologies in broader terms, is phenomenal,” says Frank Gu, an assistant professor of chemical engineering at the University of Waterloo in Canada, and an expert in nanoengineering for health care and medical applications.

“When you think about field deployment, that’s far down the road, but this paper offers a really exciting opportunity to crack a problem that is persistently present,” says Gu, who was not involved in the research. “If you take the normal conventional civil engineering or chemical engineering approach to treating it, it just won’t touch it. That’s where the most exciting part is.”

The researchers have made this illustration of their work available,

Nanoparticles that lose their stability upon irradiation with light have been designed to extract endocrine disruptors, pesticides, and other contaminants from water and soils. The system exploits the large surface-to-volume ratio of nanoparticles, while the photoinduced precipitation ensures nanomaterials are not released in the environment. Image: Nicolas Bertrand Courtesy: MIT

Nanoparticles that lose their stability upon irradiation with light have been designed to extract endocrine disruptors, pesticides, and other contaminants from water and soils. The system exploits the large surface-to-volume ratio of nanoparticles, while the photoinduced precipitation ensures nanomaterials are not released in the environment.
Image: Nicolas Bertrand Courtesy: MIT

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

Nanoparticles with photoinduced precipitation for the extraction of pollutants from water and soil by Ferdinand Brandl, Nicolas Bertrand, Eliana Martins Lima & Robert Langer. Nature Communications 6, Article number: 7765 doi:10.1038/ncomms8765 Published 21 July 2015

This paper is open access.

Herbicide nanometric sensor could help diagnose multiple sclerosis

This research into nanometric sensors and multiple sclerosis comes from Brazil. According to a June 23, 2015 news item on Nanowerk (Note: A link has been removed),

The early diagnosis of certain types of cancer, as well as nervous system diseases such as multiple sclerosis and neuromyelitis optica, may soon be facilitated by the use of a nanosensor capable of identifying biomarkers of these pathological conditions (“A Nanobiosensor Based on 4-Hydroxyphenylpyruvate Dioxygenase Enzyme for Mesotrione Detection”).

The nanobiosensor was developed at the Federal University of São Carlos (UFSCar), Sorocaba, in partnership with the São Paulo Federal Institute of Education, Science & Technology (IFSP), Itapetininga, São Paulo State, Brazil. It was originally designed to detect herbicides, heavy metals and other pollutants.

A June 23, 2015 Fundação de Amparo à Pesquisa do Estado de São Paulo news release on EurekAlert, which originated the news item, describes the sensor as it was originally used and explains its new function as a diagnostic tool for multiple sclerosis and other diseases,

“It’s a highly sensitive device, which we developed in collaboration with Alberto Luís Dario Moreau, a professor at IFSP. “We were able to increase sensitivity dramatically by going down to the nanometric scale,” said physicist Fábio de Lima Leite, a professor at UFSCar and the coordinator of the research group.

The nanobiosensor consists of a silicon nitride (Si3N4) or silicon (Si) nanoprobe with a molecular-scale elastic constant and a nanotip coupled to an enzyme, protein or other molecule.

When this molecule touches a target of interest, such as an antibody or antigen, the probe bends as the two molecules adhere. The deflection is detected and measured by the device, enabling scientists to identify the target.

“We started by detecting herbicides and heavy metals. Now we’re testing the device for use in detecting target molecules typical of nervous system diseases, in partnership with colleagues at leading centers of research on demyelinating diseases of the central nervous system”

The migration from herbicide detection to antibody detection was motivated mainly by the difficulty of diagnosing demyelinating diseases, cancer and other chronic diseases before they have advanced beyond an initial stage.

The criteria for establishing a diagnosis of multiple sclerosis or neuromyelitis optica are clinical (supplemented by MRI scans), and patients do not always present with a characteristic clinical picture. More precise diagnosis entails ruling out several other diseases.

The development of nanodevices will be of assistance in identifying these diseases and reducing the chances of false diagnosis.

The procedure can be as simple as placing a drop of the patient’s cerebrospinal fluid on a glass slide and observing its interaction with the nanobiosensor.

“If the interaction is low, we’ll be able to rule out multiple sclerosis with great confidence,” Leite said. “High interaction will indicate that the person is very likely to have the disease.” In this case, further testing would be required to exclude the possibility of a false positive.

“Different nervous system diseases have highly similar symptoms. Multiple sclerosis and neuromyelitis optica are just two examples. Even specialists experience difficulties or take a long time to diagnose them. Our technique would provide a differential diagnostic tool,” Leite said.

The next step for the group is to research biomarkers for these diseases that have not been completely mapped, including antibodies and antigens, among others. The group has begun tests for the detection of head and neck cancer.

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

A Nanobiosensor Based on 4-Hydroxyphenylpyruvate Dioxygenase Enzyme for Mesotrione Detection by P. Soto Garcia, A.L.D Moreau, J.C. Magalhaes Ierich,  A.C Araujo Vig, A.M. Higa, G.S. Oliveira, F. Camargo Abdalla, M. Hausen, & F.L. Leite. Sensors Journal, IEEE  (Volume:15 ,  Issue: 4) pp. 2106 – 2113 Date of Publication: 20 November 2014 Date of Current Version: 27 January 2015 Issue Date: April 2015  DOI 10.1109/JSEN.2014.2371773

This paper is behind a paywall.

South American countries and others visit Iran’s Nanotechnology Initiative Council

The Iran Nanotechnology Initiative Council (INIC) news release states eight South American countries visited. By my count there were six South American countries (Argentina, Brazil, Ecuador, Bolivia, Venezuela, and Uruguay,), one North American country (Mexico), and one Caribbean country (Cuba). All eight can be described as Latin American countries.

An easy to understand error (I once forgot Mexico is part of North America and, for heaven sakes, I live in Canada and really should know better) as the designations can be confusing. That cleared up, here’s what the June 15, 2015 INIC news release had to say about the visit,

The ambassadors and charge d’affaires of 8 South American countries of Argentina, Brazil, Ecuador, Bolivia, Cuba, Venezuela, Uruguay and Mexico paid a visit to Iran Nanotechnology Initiative Council (INIC) to become familiar with its activities.

Among the objectives of the visit, which was requested by the abovementioned countries, mention can be made of introduction with INIC and its activities, presentation of nanotechnology achievements and products in the country by the INIC, creation and modification of international cooperation and creation of appropriate environment for exporting nanotechnology-based products to these countries.

In this visit, the programs, achievements and objectives of nanotechnology development in Iran were explained by the authorities of INIC. In addition and due to the needs of the countries whose representatives were present in the visit, a number of experts from the Iranian knowledge-based companies presented their nanotechnology products in the fields of packaging of agricultural products with long durability and water purification.

As usual with something from INIC, I long for more detail, e.g., when did the visit take place?

H/t to Nanotechnology Now June 15, 2015 news item.

Seven miniature frog species in the Brazilian Atlantic Rainforest

Caption: One of the species of miniaturized frog found in the Brazilian Atlantic Forest, shows the extent of the miniaturization. Credit: Luiz Fernando Ribeiro, CC BY SA

Caption: One of the species of miniaturized frog found in the Brazilian Atlantic Forest, shows the extent of the miniaturization.
Credit: Luiz Fernando Ribeiro, CC BY SA

Seven new species of frogs, with many of them in the 1cm range as adults, have been found in the Brazilian Atlantic Rainforest. From a June 4, 2015 PeerJ news release on EurekAlert,

Following nearly 5 years of exploration in mountainous areas of the southern Brazilian Atlantic Rainforest, a team of researchers has uncovered seven new species of a highly miniaturized, brightly colored frog genus known as Brachycephalus. Each species is remarkably endemic, being restricted to cloud forests in one or a few adjacent mountaintops, thus making them highly vulnerable to extinction, particularly due to shifts in the distribution of cloud forest due to climate change.

The Atlantic Rainforest of Brazil harbors a highly unique group of frogs that have intrigued naturalists for over a century. Known as Brachycephalus, these frogs are among the smallest terrestrial vertebrates, with adult sizes often not exceeding 1 cm in length, leading to a variety of changes in their body structure, such as reduction in the number of toes and fingers. In addition, many species of Brachycephalus are brightly colored, possibly as a warning to the presence of a highly potent neurotoxin in their skin known as tetrodotoxin.

Most species of Brachycephalus are highly endemic, being found exclusively on one, or a few, adjacent mountaintops. Such high levels of endemism is caused by their adaptation to a specific kind of habitat – the cloud forests – which simultaneously prevents them from migrating across valleys and promotes the formation of new species.

The first species of Brachycephalus was described in 1842 by the famous German naturalist Johann Baptist von Spix, yet most species in the genus have been discovered only in the past decade, particularly due to their highly endemic nature and the difficulty in reaching remote montane sites. Over the course of five years of fieldwork, a team of researchers has provided the largest addition to the known diversity of Brachycephalus, with seven new species.

“Although getting to many of the field sites is exhausting, there was always the feeling of anticipation and curiosity about what new species could look like”, said Marcio Pie, a professor at the Universidade Federal do Paraná, who led the project.

Luiz Ribeiro, a research associate to the Mater Natura Institute for Environmental Studies, is optimistic about the prospects for future studies “This is only the beginning, especially given the fact that we have already found additional species that we are in the process of formally describing.”

A major concern regarding the new species is that the same factors that led to their endemism might also be a ticket to their extinction. Cloud forests are highly sensitive to climatic changes, and the long-term preservation of these species might involve not only the protection of their habitats but also more direct management efforts, such as rearing in captivity.

This is the first time I’ve come across a PeerJ news release, so here’s how they describe themselves in the release (Note: A link has been removed),

PeerJ is an Open Access publisher of peer reviewed articles, which offers researchers a lifetime publication plan, for a single low price, providing them with the ability to openly publish all future articles for free. PeerJ is based in San Francisco, CA and London, UK and can be accessed at https://peerj.com/. PeerJ’s mission is to help the world efficiently publish its knowledge.

All works published in PeerJ are Open Access and published using a Creative Commons license (CC-BY 4.0). Everything is immediately available–to read, download, redistribute, include in databases and otherwise use–without cost to anyone, anywhere, subject only to the condition that the original authors and source are properly attributed.

PeerJ has an Editorial Board of over 1,000 respected academics, including 5 Nobel Laureates. PeerJ was the recipient of the 2013 ALPSP Award for Publishing Innovation.

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

Seven new microendemic species of Brachycephalus (Anura: Brachycephalidae) from southern Brazil by Luiz F. Ribeiro, Marcos R. Bornschein, Ricardo Belmonte-Lopes, Carina R. Firkowski, Sergio A.A. Morato, & Marcio R. Pie. PeerJ 3:e1011 https://dx.doi.org/10.7717/peerj.1011 June 4, 2015

This is an open access paper.