Bureaucratese is not my first language so the US Food and Drug Administration’s final guidance on the use of nanomaterials in animal food seems a little vague to me. That said, here’s the Aug. 5, 2015 news item on Nanowerk, which announced the guidance (Note: A link has been removed),
The U.S. Food and Drug Administration has issued a final guidance for industry, ‘Use of Nanomaterials in Food for Animals’ (pdf), which is intended to assist industry and other stakeholders in identifying potential issues related to safety or regulatory status of food for animals containing nanomaterials or otherwise involving the application of nanotechnology. This guidance is applicable to food ingredients intended for use in animal food which (1) consist entirely of nanomaterials, (2) contain nanomaterials as a component or (3) otherwise involve the application of nanotechnology.
This final guidance addresses the legal framework for adding nanomaterial substances to food for animals and includes recommendations for submitting a Food Additive Petition (FAP) for a nanomaterial animal food ingredient. This guidance also recommends manufacturers consult with FDA early in the development of their nanomaterial animal food ingredient and before submitting an FAP. At this time, we are not aware of any animal food ingredient engineered on the nanometer scale for which there is generally available safety data sufficient to serve as the foundation for a determination that the use of such an animal food ingredient is generally recognized as safe (GRAS).
Nanotechnology is an emerging technology that allows scientists to create, explore, and manipulate materials on a scale measured in nanometers – particles so small that they cannot be seen with a regular microscope. These particles can have chemical, physical, and biological properties that differ from those of their larger counterparts, and nanotechnology has a broad range of potential applications.
Guidance documents represent the FDA’s current thinking on particular topics, policies, and regulatory issues. While “guidance for industry” documents are prepared primarily for industry, they also are used by FDA staff and other stakeholders to understand the agency’s interpretation of laws and policies.
Although this guidance has been finalized, you can submit comments at any time. To submit comments to the docket by mail, use the following address. Be sure to include docket number FDA-2013-D-1009 on each page of your written comments.
Division of Dockets Management
Food and Drug Administration
5630 Fishers Lane, Room 1061
Rockville, MD 20852
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.
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.
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?
Getting condiments out of their bottles should be a lot easier in several European countries in the near future. A June 30, 2015 news item on Nanowerk describes the technology and the business deal (Note: A link has been removed),
The days of wasting condiments — and other products — that stick stubbornly to the sides of their bottles may be gone, thanks to MIT [Massachusetts Institute of Technology] spinout LiquiGlide, which has licensed its nonstick coating to a major consumer-goods company.
Developed in 2009 by MIT’s Kripa Varanasi and David Smith, LiquiGlide is a liquid-impregnated coating that acts as a slippery barrier between a surface and a viscous liquid. Applied inside a condiment bottle, for instance, the coating clings permanently to its sides, while allowing the condiment to glide off completely, with no residue.
In 2012, amidst a flurry of media attention following LiquiGlide’s entry in MIT’s $100K Entrepreneurship Competition, Smith and Varanasi founded the startup — with help from the Institute — to commercialize the coating.
Today [June 30, 2015], Norwegian consumer-goods producer Orkla has signed a licensing agreement to use the LiquiGlide’s coating for mayonnaise products sold in Germany, Scandinavia, and several other European nations. This comes on the heels of another licensing deal, with Elmer’s [Elmer’s Glue & Adhesives], announced in March .
But this is only the beginning, says Varanasi, an associate professor of mechanical engineering who is now on LiquiGlide’s board of directors and chief science advisor. The startup, which just entered the consumer-goods market, is courting deals with numerous producers of foods, beauty supplies, and household products. “Our coatings can work with a whole range of products, because we can tailor each coating to meet the specific requirements of each application,” Varanasi says.
Apart from providing savings and convenience, LiquiGlide aims to reduce the surprising amount of wasted products — especially food — that stick to container sides and get tossed. For instance, in 2009 Consumer Reports found that up to 15 percent of bottled condiments are ultimately thrown away. Keeping bottles clean, Varanasi adds, could also drastically cut the use of water and energy, as well as the costs associated with rinsing bottles before recycling. “It has huge potential in terms of critical sustainability,” he says.
Varanasi says LiquiGlide aims next to tackle buildup in oil and gas pipelines, which can cause corrosion and clogs that reduce flow. [emphasis mine] Future uses, he adds, could include coatings for medical devices such as catheters, deicing roofs and airplane wings, and improving manufacturing and process efficiency. “Interfaces are ubiquitous,” he says. “We want to be everywhere.”
The news release goes on to describe the research process in more detail and offers a plug for MIT’s innovation efforts,
LiquiGlide was originally developed while Smith worked on his graduate research in Varanasi’s research group. Smith and Varanasi were interested in preventing ice buildup on airplane surfaces and methane hydrate buildup in oil and gas pipelines.
Some initial work was on superhydrophobic surfaces, which trap pockets of air and naturally repel water. But both researchers found that these surfaces don’t, in fact, shed every bit of liquid. During phase transitions — when vapor turns to liquid, for instance — water droplets condense within microscopic gaps on surfaces, and steadily accumulate. This leads to loss of anti-icing properties of the surface. “Something that is nonwetting to macroscopic drops does not remain nonwetting for microscopic drops,” Varanasi says.
Inspired by the work of researcher David Quéré, of ESPCI in Paris, on slippery “hemisolid-hemiliquid” surfaces, Varanasi and Smith invented permanently wet “liquid-impregnated surfaces” — coatings that don’t have such microscopic gaps. The coatings consist of textured solid material that traps a liquid lubricant through capillary and intermolecular forces. The coating wicks through the textured solid surface, clinging permanently under the product, allowing the product to slide off the surface easily; other materials can’t enter the gaps or displace the coating. “One can say that it’s a self-lubricating surface,” Varanasi says.
Mixing and matching the materials, however, is a complicated process, Varanasi says. Liquid components of the coating, for instance, must be compatible with the chemical and physical properties of the sticky product, and generally immiscible. The solid material must form a textured structure while adhering to the container. And the coating can’t spoil the contents: Foodstuffs, for instance, require safe, edible materials, such as plants and insoluble fibers.
To help choose ingredients, Smith and Varanasi developed the basic scientific principles and algorithms that calculate how the liquid and solid coating materials, and the product, as well as the geometry of the surface structures will all interact to find the optimal “recipe.”
Today, LiquiGlide develops coatings for clients and licenses the recipes to them. Included are instructions that detail the materials, equipment, and process required to create and apply the coating for their specific needs. “The state of the coating we end up with depends entirely on the properties of the product you want to slide over the surface,” says Smith, now LiquiGlide’s CEO.
Having researched materials for hundreds of different viscous liquids over the years — from peanut butter to crude oil to blood — LiquiGlide also has a database of optimal ingredients for its algorithms to pull from when customizing recipes. “Given any new product you want LiquiGlide for, we can zero in on a solution that meets all requirements necessary,” Varanasi says.
MIT: A lab for entrepreneurs
For years, Smith and Varanasi toyed around with commercial applications for LiquiGlide. But in 2012, with help from MIT’s entrepreneurial ecosystem, LiquiGlide went from lab to market in a matter of months.
Initially the idea was to bring coatings to the oil and gas industry. But one day, in early 2012, Varanasi saw his wife struggling to pour honey from its container. “And I thought, ‘We have a solution for that,’” Varanasi says.
The focus then became consumer packaging. Smith and Varanasi took the idea through several entrepreneurship classes — such as 6.933 (Entrepreneurship in Engineering: The Founder’s Journey) — and MIT’s Venture Mentoring Service and Innovation Teams, where student teams research the commercial potential of MIT technologies.
“I did pretty much every last thing you could do,” Smith says. “Because we have such a brilliant network here at MIT, I thought I should take advantage of it.”
That May , Smith, Varanasi, and several MIT students entered LiquiGlide in the MIT $100K Entrepreneurship Competition, earning the Audience Choice Award — and the national spotlight. A video of ketchup sliding out of a LiquiGlide-coated bottle went viral. Numerous media outlets picked up the story, while hundreds of companies reached out to Varanasi to buy the coating. “My phone didn’t stop ringing, my website crashed for a month,” Varanasi says. “It just went crazy.”
That summer , Smith and Varanasi took their startup idea to MIT’s Global Founders’ Skills Accelerator program, which introduced them to a robust network of local investors and helped them build a solid business plan. Soon after, they raised money from family and friends, and won $100,000 at the MassChallenge Entrepreneurship Competition.
When LiquiGlide Inc. launched in August 2012, clients were already knocking down the door. The startup chose a select number to pay for the development and testing of the coating for its products. Within a year, LiquiGlide was cash-flow positive, and had grown from three to 18 employees in its current Cambridge headquarters.
Looking back, Varanasi attributes much of LiquiGlide’s success to MIT’s innovation-based ecosystem, which promotes rapid prototyping for the marketplace through experimentation and collaboration. This ecosystem includes the Deshpande Center for Technological Innovation, the Martin Trust Center for MIT Entrepreneurship, the Venture Mentoring Service, and the Technology Licensing Office, among other initiatives. “Having a lab where we could think about … translating the technology to real-world applications, and having this ability to meet people, and bounce ideas … that whole MIT ecosystem was key,” Varanasi says.
I had thought the EU (European Union) offered more roadblocks to marketing nanotechnology-enabled products used in food packaging than the US. If anyone knows why a US company would market its products in Europe first I would love to find out.
The researchers haven’t published a study and they have used fruit flies as their testing mechanism (animal models) so, it’s a little difficult (futile) to analyze the work at this stage but it is intriguing. A June 9, 2015 news item on Azonano announces a research collaboration designed to examine the impact engineered nanoparticles have on the gut and the gut microbiome,
Researchers at Binghamton University believe understanding nano particles’ ability to influence our metabolic processing may be integral to mediating metabolic disorders and obesity, both of which are on the rise and have been linked to processed foods.
Anthony Fiumera, associate professor of biological sciences, and Gretchen Mahler, assistant professor of biomedical engineering, are collaborating on a research project funded by a Binghamton University Transdisciplinary Areas of Excellence (TAE) grant to discover the role ingested nanoparticles play in the physiology and function of the gut and gut microbiome.
The gut microbiome is the population of microbes living within the human intestine, consisting of tens of trillions of microorganisms (including at least 1,000 different species of known bacteria). Nanoparticles, which are often added to processed foods to enhance texture and color, have been linked to changes in gut function. As processed foods become more common elements of our diet, there has been a significant increase in concentrations of these particles found in the human body.
Fiumera works in vivo with fruit flies while Mahler works in vitro using a 3-D cell-culture model of the gastrointestinal (GI) tract to understand how ingesting nanoparticles influences glucose processing and the gut microbiome. By using complementary research methods, the researchers have helped advance each other’s understanding of nanoparticles.
Using fruit flies, Fiumera looks at the effects of nanoparticles on development, physiology and biochemical composition, as well as the microbial community in the GI tract of the fly. The fly model offers two advantages: 1) research can be done on a wide range of traits that might be altered by changes in metabolism and 2) the metabolic processes within the fly are similar to those in humans. Fiumera also aims to investigate which genes are associated with responses to the nanoparticles, which ultimately may help us understand why individuals react differently to nanoparticles.
For this project, Mahler expanded her GI tract model to include a commensal intestinal bacterial species and used the model to determine a more detailed mechanism of the role of nanoparticle exposure on gut bacteria and intestinal function. Early results have shown that nanoparticle ingestion alters glucose absorption, and that the presence of beneficial gut bacteria eliminates these effects.
Mahler was already investigating nanoparticles when she reached out to Fiumera and proposed they combine their respective expertise. With the help of undergraduate students Gabriella Shull and John Fountain and graduate student Jonathan Richter, Fiumera and Mahler have begun to uncover some effects of ingesting nanoparticles. Since they are using realistic, low concentrations of nanoparticles, the effects are slight, but eventually may be additive.
The most interesting aspect of this research (to me) is the notion that the impact may be additive. In short, you might be able to tolerate a few more nanoparticles in your gut but as more engineered nanoparticles become part of our food and drink (including water) and your gut receives more and more that tolerance may no longer possible.
There is increasing concern about engineered nanoparticles as they cycle through environment and the US Environmental Protection Agency (EPA) funded a programed by Arizona State University (ASU), LCnano Network (part of the EPA’s larger Life Cycle of Nanomaterials project). You can find out more about the ASU program in my April 8, 2014 post (scroll down about 50% of the way).
Getting back to Binghamton, I look forward to hearing more about the research as it progresses.
I’m back in Florida (US), so to speak. Last mentioned here in an April 7, 2015 post about citrus canker and zinkicide, a story about a disease which endangers citrus production in the US, this latest story concerns a possible solution to the problem of a fungus, which attacks ornamental horticultural plants in Florida. From a May 5, 2015 news item on Azonano,
Deep in the soil, underneath more than 400 plant and tree species, lurks a lethal fungus threatening Florida’s $15 billion a year ornamental horticulture industry.
But University of Florida plant pathologist G. Shad Ali has found an economical and eco-friendly way to combat the plant destroyer known as phytophthora before it attacks the leaves and roots of everything from tomato plants to oak trees.
Ali and a team of researchers with UF’s Institute of Food and Agricultural Sciences, along with the University of Central Florida and the New Jersey Institute of Technology, have found that silver nanoparticles produced with an extract of wormwood, an herb with strong antioxidant properties, can stop several strains of the deadly fungus.
“The silver nanoparticles are extremely effective in eliminating the fungus in all stages of its life cycle,” Ali said. “In addition, it has no adverse effects on plant growth.” [emphasis mine]
The silver nanoparticles measure 5 to 100 nanometers in diameter – about one one-thousandth the width of a human hair. Once the nanoparticles are sprayed onto a plant, they shield it from fungus. Since the nanoparticles display multiple ways of inhibiting fungus growth, the chances of pathogens developing resistance to them are minimized, Ali said. Because of that, they may be used for controlling fungicide-resistant plant pathogens more effectively.
That’s good news for the horticulture industry. Worldwide crop losses due to phytophthora fungus diseases are estimated to be in the multibillion dollar range, with $6.7 billion in losses in potato crops due to late blight – the cause of the Irish Potato Famine in the mid-1800s when more than 1 million people died – and $1 billion to $2 billion in soybean loss.
Silver nanoparticles are being investigated for applications in various industries, including medicine, diagnostics, cosmetics and food processing. They already are used in wound dressings, food packaging and in consumer products such as textiles and footwear for fighting odor-causing microorganisms.
Other members of the UF research team were Mohammad Ali, a visiting doctoral student from the Quaid-i-Azam University, Islamabad, Pakistan; David Norman and Mary Brennan with the University of Florida’s Plant Pathology-Mid Florida Research and Education Center; Bosung Kim with the University of Central Florida’s chemistry department; Kevin Belfield with the College of Science and Liberal Arts at the New Jersey Institute of Technology and the University of Central Florida’s chemistry department.
Ali’s comment about silver nanoparticles not having any adverse effects on plant growth is in contrast to findings by Mark Wiesner and other researchers at Duke University (North Carolina, US). From my Feb. 28, 2013 posting (which also features a Finnish-Estonia study showing no adverse effects from silver nanoparticles in crustaceans),
… there’s a study from Duke University suggests that silver nanoparticles in wastewater which is later put to agricultural use may cause problems. From the Feb. 27, 2013 news release on EurekAlert,
In experiments mimicking a natural environment, Duke University researchers have demonstrated that the silver nanoparticles used in many consumer products can have an adverse effect on plants and microorganisms.
The main route by which these particles enter the environment is as a by-product of water and sewage treatment plants. [emphasis] The nanoparticles are too small to be filtered out, so they and other materials end up in the resulting “sludge,” which is then spread on the land surface as a fertilizer.
The researchers found that one of the plants studied, a common annual grass known as Microstegium vimeneum, had 32 percent less biomass in the mesocosms treated with the nanoparticles. Microbes were also affected by the nanoparticles, Colman [Benjamin Colman, a post-doctoral fellow in Duke’s biology department and a member of the Center for the Environmental Implications of Nanotechnology (CEINT)] said. One enzyme associated with helping microbes deal with external stresses was 52 percent less active, while another enzyme that helps regulate processes within the cell was 27 percent less active. The overall biomass of the microbes was also 35 percent lower, he said.
“Our field studies show adverse responses of plants and microorganisms following a single low dose of silver nanoparticles applied by a sewage biosolid,” Colman said. “An estimated 60 percent of the average 5.6 million tons of biosolids produced each year is applied to the land for various reasons, and this practice represents an important and understudied route of exposure of natural ecosystems to engineered nanoparticles.”
“Our results show that silver nanoparticles in the biosolids, added at concentrations that would be expected, caused ecosystem-level impacts,” Colman said. “Specifically, the nanoparticles led to an increase in nitrous oxide fluxes, changes in microbial community composition, biomass, and extracellular enzyme activity, as well as species-specific effects on the above-ground vegetation.”
Getting back to Florida, you can find Ali’s abstract here,
For anyone who recognized that wormwood is a constituent of Absinthe, a liquor that is banned in many parts of the world due to possible side effects associated with the wormwood, here’s more about it from the Wormwood overview page on WebMD (Note: Links have been removed),
Wormwood is an herb. The above-ground plant parts and oil are used for medicine.
Wormwood is used in some alcoholic beverages. Vermouth, for example, is a wine beverage flavored with extracts of wormwood. Absinthe is another well-known alcoholic beverage made with wormwood. It is an emerald-green alcoholic drink that is prepared from wormwood oil, often along with other dried herbs such as anise and fennel. Absinthe was popularized by famous artists and writers such as Toulouse-Lautrec, Degas, Manet, van Gogh, Picasso, Hemingway, and Oscar Wilde. It is now banned in many countries, including the U.S. But it is still allowed in European Union countries as long as the thujone content is less than 35 mg/kg. Thujone is a potentially poisonous chemical found in wormwood. Distilling wormwood in alcohol increases the thujone concentration.
Returning to the matter at hand, as I’ve noted previously elsewhere, research into the toxic effects associated with nanomaterials (e.g. silver nanoparticles) is a complex process.
What happens when you eat or drink nanoparticles, metallic or otherwise? No one really knows. Part of the problem with doing research now is there are no benchmarks for the quantity we’ve been ingesting over the centuries. Nanoparticles do occur naturally, as well, people who’ve eaten with utensils made of or coated with silver or gold have ingested silver or gold nanoparticles that were shed by those very utensils. In short, we’ve been ingesting any number of nanoparticles through our food, drink, and utensils in addition to the engineered nanoparticles that are found in consumer products. So, part of what researchers need to determine is the point at which we need to be concerned about nanoparticles. That’s trickier than it might seem since we ingest our nanoparticles and recycle them into the environment (air, water, soil) to reingest (inhale, drink, eat, etc.) them at a later date. The endeavour to understand what impact engineered nanoparticles in particular will have on us as more are used in our products is akin to assembling a puzzle.
There’s a May 5, 2015 news item on Azonano which describes research into the effects that metallic nanoparticles have on the micriobiome (bacteria) in our guts,
Exposure of a model human colon to metal oxide nanoparticles, at levels that could be present in foods, consumer goods, or treated drinking water, led to multiple, measurable differences in the normal microbial community that inhabits the human gut. The changes observed in microbial metabolism and the gut microenvironment with exposure to nanoparticles could have implications for overall human health, as discussed in an article published in Environmental Engineering Science, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available free on the Environmental Engineering Science website until June 1, 2015.
Alicia Taylor, Ian Marcus, Risa Guysi, and Sharon Walker, University of California, Riverside, individually introduced three different nanoparticles–zinc oxide, cerium dioxide, and titanium dioxide–commonly used in products such as toothpastes, cosmetics, sunscreens, coatings, and paints, into a model of the human colon. The model colon mimics the normal gut environment and contains the microorganisms typically present in the human microbiome.
In the article “Metal Oxide Nanoparticles Induce Minimal Phenotypic Changes in a Model Colon Gut Microbiota” the researchers described changes in both specific characteristics of the microbial community and of the gut microenvironment after exposure to the nanoparticles.
I’ve taken a quick look at the research while it’s still open access (till June 1, 2015) to highlight the bits I consider interesting. There’s this about the nanoparticle (NP) quantities used in the study (Note: Links have been removed),
Environmentally relevant NP concentrations were chosen to emulate human exposures to NPs through ingestion of both food and drinking water at 0.01 μg/L ZnO NP, 0.01 μg/L CeO2 NP, and 3 mg/L TiO2 NP (Gottschalk et al., 2009; Kiser et al., 2009, 2013; Weir et al., 2012; Keller and Lazareva, 2013). Recent work has also indicated that adults in the USA ingest 5 mg TiO2 per day, half of which is in the nano-size range (Lomer et al., 2000; Powell et al., 2010). Exposure routes and reliable dosing information of NPs that are embedded in solid matrices are difficult to predict, and this is often a limitation of analytical techniques (Nowack et al., 2012; Yang and Westerhoff, 2014). The exposure levels used in this study were predominately selected from literature values that give predictions on amount of NPs in water and food sources (Gottschalk et al., 2009; Kiser et al., 2009; Weir et al., 2012; Keller and Lazareva, 2013; Keller et al., 2013).
For anyone unfamiliar with chemical notations, ZnO NP is zinc oxide nanoparticle, 0.01 μg/L is one/one hundredth of a microgram per litre, CeO2 is cesisum dioxide NP, and TiO2 is titanium dioxide NP while 3 mg/L, is 3 milligrams per litre.
After assuring the quantities used in the study are the same as they expect humans to be ingesting on a regular basis, the researchers describe some of the factors which may affect the interaction between the tested nanoparticles and the bacteria (Note: Links have been removed),
It is essential to note that interactions between NPs and bacteria in the intestines may be dependent on numerous factors: the surface charge of the NPs and bacteria, the chemical composition and surface charge of the digested food, and variability in diet. These factors may ultimately correlate to effects seen in humans on an individual basis. In fact, similar work has demonstrated that exposing common NPs found in food to stomach-like conditions will change their surface chemistry from negative to neutral or positive, causing the NPs to interact with negatively charged mucus proteins in the gastrointestinal tract and, in turn, affecting the transport of NPs within the intestine (McCracken et al., 2013). The purpose of this work was to measure responses of the microbial community during the NP exposures. Based on previous research, it is anticipated that the NPs altered by stomach-like conditions would also cause changes in the gut environment (McCracken et al., 2013).
Here’s some of what they discovered,
Our initial hypothesis, that NPs induce phenotypic changes in a gut microbial community, was affirmed through significant measurable effects seen in the data. Tests that supported that NPs caused changes in the phenotype included hydrophobicity, EPM, sugar content of the EPS, cell size, conductivity, and SFCA (specifically butyric acid) production. Data for cell concentration and the protein content of the EPS demonstrated no significant results. Data were inconclusive for pH. With such a complex biological system, it is very likely that the phenotypic and biochemical changes observed are combinations of responses happening in parallel. The effects seen may be attributed to both changes induced by the NPs and natural phenomena associated with microbial community activity and other metabolic processes in a multifaceted environment such as the gut. Some examples of natural processes that could also influence the phenotypic and biochemical parameters are osmolarity, active metabolites, and electrolyte concentrations (Miller and Wood, 1996; Record et al., 1998).
Here’s the concluding sentence from the abstract,
Overall, the NPs caused nonlethal, significant changes to the microbial community’s phenotype, which may be related to overall health effects. [emphasis mine]
This research like the work I featured in a June 27, 2013 posting points to some issues with researching the impact that nanoparticles may have on our bodies. There was no cause for immediate alarm in 2013 and it appears that is still the case in 2015. However, that assumes quantities being ingested don’t increase significantly.
I wonder just how much funding the US Dept. of Agriculture (USDA) is devoting to nanotechnology this year (2015). I first came across an announcement of $23M in the body of a news item about Zinkicide (my April 7, 2015 posting),
Found in Florida orchards in 2005, a citrus canker, citrus greening, poses a serious threat to the US state’s fruit industry. An April 2, 2105 news item on phys.org describes a possible solution to the problem,
Since it was discovered in South Florida in 2005, the plague of citrus greening has spread to nearly every grove in the state, stoking fears among growers that the $10.7 billion-a-year industry may someday disappear.
Now the U.S. Department of Agriculture has awarded the University of Florida a $4.6 million grant aimed at testing a potential new weapon in the fight against citrus greening: Zinkicide, a bactericide invented by a nanoparticle researcher at the University of Central Florida.
An April 29, 2015 article by Diego Flammini for Farm.com describes the latest USDA nanotechnology funding announcement,
In an effort to increase America’s food security, nutrition, food safety and environmental protection, the United States Department of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA) announced $3.8 million in nanotechnology research grants.
Flammini lists three of the eight recipients,
University of Georgia
With $496,192, the research team will develop different sensors that are able to detect fungal pathogens in crops. The project will also develop a smartphone app for farmers to have so they can access their information whenever necessary.
The school will use its $450,000 to conduct a nationwide survey about nanotechnology and gauge consumer beliefs about it and its relationship to health. Among the specifics it will touch on is the use of visuals to communicate nanotechnology.
University of Massachusetts
The researchers will concentrate their $444,200 on developing a platform to detect pathogens in food that is better than the current methods.
An April 30, 2015 news item on Azonano describes essential oil research at Wayne State University (Detroit, Michigan, US),
Nearly half of foodborne illnesses in the U.S. from 1998 through 2008 have been attributed to contaminated fresh produce. Prevention and control of bacterial contamination on fresh produce is critical to ensure food safety. The current strategy remains industrial washing of the product in water containing chlorine. However, due to sanitizer ineffectiveness there is an urgent need to identify alternative antimicrobials, particularly those of natural origin, for the produce industry.
A team of researchers at Wayne State University have been exploring natural, safe and alternative antimicrobials to reduce bacterial contamination. Plant essential oils such as those from thyme, oregano and clove are known to have a strong antimicrobial effect, but currently their use in food protection is limited due to their low solubility in water. The team, led by Yifan Zhang, Ph.D., assistant professor of nutrition and food science in the College of Liberal Arts and Sciences, explored ways to formulate oil nanoemulsions to increase the solubility and stability of essential oils, and consequently, enhance their antimicrobial activity.
“Much of the research on the antimicrobial efficacy of essential oils has been conducted using products made by mixing immiscible oils in water or phosphate buffered saline,” said Zhang. “However, because of the hydrophobic nature of essential oils, organic compounds from produce may interfere with reducing the sanitizing effect or duration of the effectiveness of these essential oils. Our team set out to find a new approach to inhibit these bacteria with the use of oregano oil, one of the most effective plant essential oils with antimicrobial effect.”
Zhang, and then-Ph.D. student, Kanika Bhargava, currently assistant professor of human environmental sciences at the University of Central Oklahoma, approached Sandro da Rocha, Ph.D., associate professor of chemical engineering and materials science in the College of Engineering at Wayne State, to explore options.
“In our research, we discovered that oregano oil was able to inhibit common foodborne bacteria, such as E. coli O157, Salmonella and Listeria, in artificially contaminated fresh lettuce” said Zhang. “We wanted to explore the possibility of a nanodelivery system for the oil, which is an area of expertise of Dr. da Rocha.”
The team initially considered the use of solid polymeric nanoparticles for the delivery of the oil, but da Rocha suggested the use of nanoemulsions.
“My team felt the use of nanoemulsions would improve the rate of release compared to other nanoformulations, and the ability of the food grade surfactant to wet the surface of the produce,” said da Rocha. “We were able to reduce L. monocytogenes, S. Typhimurium, and E. coli O157 on fresh lettuce. Former Ph.D. student Denise S. Conti, now at the Generics Division of the FDA, helped design the nanocarriers and characterize them.”
The team added that while there is still work to be done, their study suggests promise for the use of essential oil nanoemulsions as a natural alternative to chemicals for safety controls in produce.
“Our future research aims to investigate the antimicrobial effects of essential oil nanoemulsions in various combinations, as well as formulate the best proportions of each ingredient at the lowest possible necessary levels needed for food application, which ultimately will aid in maintaining the taste of the produce.”
Courtesy: MIT (Massachusetts Institute of Technology)
I love this .gif; it says a lot without a word. However for details, you need words and here’s what an April 15, 2015 news item on Nanowerk has to say about the research illustrated by the .gif,
MIT [Massachusetts Institute of Technology] chemists have devised an inexpensive, portable sensor that can detect gases emitted by rotting meat, allowing consumers to determine whether the meat in their grocery store or refrigerator is safe to eat.
The sensor, which consists of chemically modified carbon nanotubes, could be deployed in “smart packaging” that would offer much more accurate safety information than the expiration date on the package, says Timothy Swager, the John D. MacArthur Professor of Chemistry at MIT.
It could also cut down on food waste, he adds. “People are constantly throwing things out that probably aren’t bad,” says Swager, who is the senior author of a paper describing the new sensor this week in the journal Angewandte Chemie.
This latest study is builds on previous work at Swager’s lab (Note: Links have been removed),
The sensor is similar to other carbon nanotube devices that Swager’s lab has developed in recent years, including one that detects the ripeness of fruit. All of these devices work on the same principle: Carbon nanotubes can be chemically modified so that their ability to carry an electric current changes in the presence of a particular gas.
In this case, the researchers modified the carbon nanotubes with metal-containing compounds called metalloporphyrins, which contain a central metal atom bound to several nitrogen-containing rings. Hemoglobin, which carries oxygen in the blood, is a metalloporphyrin with iron as the central atom.
For this sensor, the researchers used a metalloporphyrin with cobalt at its center. Metalloporphyrins are very good at binding to nitrogen-containing compounds called amines. Of particular interest to the researchers were the so-called biogenic amines, such as putrescine and cadaverine, which are produced by decaying meat.
When the cobalt-containing porphyrin binds to any of these amines, it increases the electrical resistance of the carbon nanotube, which can be easily measured.
“We use these porphyrins to fabricate a very simple device where we apply a potential across the device and then monitor the current. When the device encounters amines, which are markers of decaying meat, the current of the device will become lower,” Liu says.
In this study, the researchers tested the sensor on four types of meat: pork, chicken, cod, and salmon. They found that when refrigerated, all four types stayed fresh over four days. Left unrefrigerated, the samples all decayed, but at varying rates.
There are other sensors that can detect the signs of decaying meat, but they are usually large and expensive instruments that require expertise to operate. “The advantage we have is these are the cheapest, smallest, easiest-to-manufacture sensors,” Swager says.
“There are several potential advantages in having an inexpensive sensor for measuring, in real time, the freshness of meat and fish products, including preventing foodborne illness, increasing overall customer satisfaction, and reducing food waste at grocery stores and in consumers’ homes,” says Roberto Forloni, a senior science fellow at Sealed Air, a major supplier of food packaging, who was not part of the research team.
The new device also requires very little power and could be incorporated into a wireless platform Swager’s lab recently developed that allows a regular smartphone to read output from carbon nanotube sensors such as this one.
The funding sources are interesting, as I am appreciating with increasing frequency these days (from the news release),
The researchers have filed for a patent on the technology and hope to license it for commercial development. The research was funded by the National Science Foundation and the Army Research Office through MIT’s Institute for Soldier Nanotechnologies.
There are other posts here about the quest to create food sensors including this Sept. 26, 2013 piece which features a critique (by another blogger) about trying to create food sensors that may be more expensive than the item they are protecting, a problem Swager claims to have overcome in an April 17, 2015 article by Ben Schiller for Fast Company (Note: Links have been removed),
Swager has set up a company to commercialize the technology and he expects to do the first demonstrations to interested clients this summer. The first applications are likely to be for food workers working with meat and fish, but there’s no reason why consumers shouldn’t get their own devices in due time.
There are efforts to create visual clues for food status. But Swager says his method is better because it doesn’t rely on perception: it produces hard data that can be logged and tracked. And it also has potential to be very cheap.
“The resistance method is a game-changer because it’s two to three orders of magnitude cheaper than other technology. It’s hard to imagine doing this cheaper,” he says.
Happily, I’m getting more nanotechnology (for the most part) information from Japan. Given Japan’s prominence in this field of endeavour I’ve long felt FrogHeart has not adequately represented Japanese contributions. Now that I’m receiving English language translations, I hope to better address the situation.
This morning (March 26, 2015), there were two news releases from Kawasaki INnovation Gateway at SKYFRONT (KING SKYFRONT), Coastal Area International Strategy Office, Kawasaki City, Japan in my mailbox. Before getting on to the news releases, here’s a little about the city of Kawasaki and about its innovation gateway. From the Kawasaki, Kanagawa entry in Wikipedia (Note: Links have been removed),
Kawasaki (川崎市 Kawasaki-shi?) is a city in Kanagawa Prefecture, Japan, located between Tokyo and Yokohama. It is the 9th most populated city in Japan and one of the main cities forming the Greater Tokyo Area and Keihin Industrial Area.
Kawasaki occupies a belt of land stretching about 30 kilometres (19 mi) along the south bank of the Tama River, which divides it from Tokyo. The eastern end of the belt, centered on JR Kawasaki Station, is flat and largely consists of industrial zones and densely built working-class housing, the Western end mountainous and more suburban. The coastline of Tokyo Bay is occupied by vast heavy industrial complexes built on reclaimed land.
There is a 2014 video about Kawasaki’s innovation gateway, which despite its 14 mins. 39 secs. running time I am embedding here. (Caution: They highlight their animal testing facility at some length.)
Now on to the two news releases. The first concerns research on gold nanoparticles that was published in 2014. From a March 26, 2015 Kawasaki INnovation Gateway news release,
Gold nanoparticles size up to cancer treatment
Incorporating gold nanoparticles helps optimise treatment carrier size and stability to improve delivery of cancer treatment to cells.
Treatments that attack cancer cells through the targeted silencing of cancer genes could be developed using small interfering RNA molecules (siRNA). However delivering the siRNA into the cells intact is a challenge as it is readily degraded by enzymes in the blood and small enough to be eliminated from the blood stream by kidney filtration. Now Kazunori Kataoka at the University of Tokyo and colleagues at Tokyo Institute of Technology have designed a protective treatment delivery vehicle with optimum stability and size for delivering siRNA to cells.
The researchers formed a polymer complex with a single siRNA molecule. The siRNA-loaded complex was then bonded to a 20 nm gold nanoparticle, which thanks to advances in synthesis techniques can be produced with a reliably low size distribution. The resulting nanoarchitecture had the optimum overall size – small enough to infiltrate cells while large enough to accumulate.
In an assay containing heparin – a biological anti-coagulant with a high negative charge density – the complex was found to release the siRNA due to electrostatic interactions. However when the gold nanoparticle was incorporated the complex remained stable. Instead, release of the siRNA from the complex with the gold nanoparticle could be triggered once inside the cell by the presence of glutathione, which is present in high concentrations in intracellular fluid. The glutathione bonded with the gold nanoparticles and the complex, detaching them from each other and leaving the siRNA prone to release.
The researchers further tested their carrier in a subcutaneous tumour model. The authors concluded that the complex bonded to the gold nanoparticle “enabled the efficient tumor accumulation of siRNA and significant in vivo gene silencing effect in the tumor, demonstrating the potential for siRNA-based cancer therapies.”
The news release provides links to the March 2015 newsletter which highlights this research and to the specific article and video,
The second March 26, 2015 Kawasaki INnovation Gateway news release concerns a DNA chip and food-borne pathogens,
Rapid and efficient DNA chip technology for testing 14 major types of food borne pathogens
Conventional methods for testing food-borne pathogens is based on the cultivation of pathogens, a process that is complicated and time consuming. So there is demand for alternative methods to test for food-borne pathogens that are simpler, quick and applicable to a wide range of potential applications.
Now Toshiba Ltd and Kawasaki City Institute for Public Health have collaborated in the development of a rapid and efficient automatic abbreviated DNA detection technology that can test for 14 major types of food borne pathogens. The so called ‘DNA chip card’ employs electrochemical DNA chips and overcomes the complicated procedures associated with genetic testing of conventional methods. The ‘DNA chip card’ is expected to find applications in hygiene management in food manufacture, pharmaceuticals, and cosmetics.
The so-called automatic abbreviated DNA detection technology ‘DNA chip card’ was developed by Toshiba Ltd and in a collaboration with Kawasaki City Institute for Public Health, used to simultaneously detect 14 different types of food-borne pathogens in less than 90 minutes. The detection sensitivity depends on the target pathogen and has a range of 1E+01~05 cfu/mL.
Notably, such tests would usually take 4-5 days using conventional methods based on pathogen cultivation. Furthermore, in contrast to conventional DNA protocols that require high levels of skill and expertise, the ‘DNA chip card’ only requires the operator to inject nucleic acid, thereby making the procedure easier to use and without specialized operating skills.
Examples of pathogens associated with food poisoning that were tested with the “DNA chip card”
Enterohemorrhagic Escherichia coli
Enterotoxigenic Escherichia coli
Enteroaggregative Escherichia coli
Enteropathogenic Escherichia coli
I think 14 is the highest number of tests I’ve seen for one of these chips. This chip is quite an achievement.
One final bit from the news release about the DNA chip provides a brief description of the gateway and something they call King SkyFront,
About KING SKYFRONT
The Kawasaki INnovation Gateway (KING) SKYFRONT is the flagship science and technology innovation hub of Kawasaki City. KING SKYFRONT is a 40 hectare area located in the Tonomachi area of the Keihin Industrial Region that spans Tokyo and Kanagawa Prefecture and Tokyo International Airport (also often referred to as Haneda Airport).
KING SKYFRONT was launched in 2013 as a base for scholars, industrialists and government administrators to work together to devise real life solutions to global issues in the life sciences and environment.
I find this emphasis on the city interesting. It seems that cities are becoming increasingly important and active where science research and development are concerned. Europe seems to have adopted a biannual event wherein a city is declared a European City of Science in conjunction with the EuroScience Open Forum (ESOF) conferences. The first such city was Dublin in 2012 (I believe the Irish came up with the concept themselves) and was later adopted by Copenhagen for 2014. The latest city to embrace the banner will be Manchester in 2016.