Category Archives: health and safety

DNA as a sensor

McMaster University (Ontario, Canada) researchers have developed a technique for using DNA (deoxyribonucleic acid) as a sensor according to a July 7, 2016 news item on ScienceDaily,

Researchers at McMaster University have established a way to harness DNA as the engine of a microscopic “machine” they can turn on to detect trace amounts of substances that range from viruses and bacteria to cocaine and metals.

“It’s a completely new platform that can be adapted to many kinds of uses,” says John Brennan, director of McMaster’s Biointerfaces Insitute and co-author of a paper in the journal Nature Communications that describes the technology. “These DNA nano-architectures are adaptable, so that any target should be detectable.”

A July 7, 2016 McMaster University news release (also on EurekAlert), which originated the news item, expands on the theme,

DNA is best known as a genetic material, but is also a very programmable molecule that lends itself to engineering for synthetic applications.

The new method shapes separately programmed pieces of DNA material into pairs of interlocking circles.

The first remains inactive until it is released by the second, like a bicycle wheel in a lock. When the second circle, acting as the lock, is exposed to even a trace of the target substance, it opens, freeing the first circle of DNA, which replicates quickly and creates a signal, such as a colour change.

“The key is that it’s selectively triggered by whatever we want to detect,” says Brennan, who holds the Canada Research Chair in Bioanalytical Chemistry and Biointerfaces. “We have essentially taken a piece of DNA and forced it to do something it was never designed to do. We can design the lock to be specific to a certain key. All the parts are made of DNA, and ultimately that key is defined by how we build it.”

The idea for the “DNA nanomachine” comes from nature itself, explains co-author Yingfu Li, who holds the Canada Research Chair in Nucleic Acids Research.

“Biology uses all kinds of nanoscale molecular machines to achieve important functions in cells,” Li says. “For the first time, we have designed a DNA-based nano-machine that is capable of achieving ultra-sensitive detection of a bacterial pathogen.”

The DNA-based nanomachine is being further developed into a user-friendly detection kit that will enable rapid testing of a variety of substances, and could move to clinical testing within a year.

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

Programming a topologically constrained DNA nanostructure into a sensor by Meng Liu, Qiang Zhang, Zhongping Li, Jimmy Gu, John D. Brennan, & Yingfu Li. Nature Communications 7, Article number: 12074  doi:10.1038/ncomms12074 Published 23 June 2016

This paper is open access.

Wireless, wearable carbon nanotube-based gas sensors for soldiers

Researchers at MIT (Massachusetts Institute of Technology) are hoping to make wireless, toxic gas detectors the size of badges. From a June 30, 2016 news item on Nanowerk,

MIT researchers have developed low-cost chemical sensors, made from chemically altered carbon nanotubes, that enable smartphones or other wireless devices to detect trace amounts of toxic gases.

Using the sensors, the researchers hope to design lightweight, inexpensive radio-frequency identification (RFID) badges to be used for personal safety and security. Such badges could be worn by soldiers on the battlefield to rapidly detect the presence of chemical weapons — such as nerve gas or choking agents — and by people who work around hazardous chemicals prone to leakage.

A June 30, 2016 MIT news release (also on EurekAlert), which originated the news item, describes the technology further,

“Soldiers have all this extra equipment that ends up weighing way too much and they can’t sustain it,” says Timothy Swager, the John D. MacArthur Professor of Chemistry and lead author on a paper describing the sensors that was published in the Journal of the American Chemical Society. “We have something that would weigh less than a credit card. And [soldiers] already have wireless technologies with them, so it’s something that can be readily integrated into a soldier’s uniform that can give them a protective capacity.”

The sensor is a circuit loaded with carbon nanotubes, which are normally highly conductive but have been wrapped in an insulating material that keeps them in a highly resistive state. When exposed to certain toxic gases, the insulating material breaks apart, and the nanotubes become significantly more conductive. This sends a signal that’s readable by a smartphone with near-field communication (NFC) technology, which allows devices to transmit data over short distances.

The sensors are sensitive enough to detect less than 10 parts per million of target toxic gases in about five seconds. “We are matching what you could do with benchtop laboratory equipment, such as gas chromatographs and spectrometers, that is far more expensive and requires skilled operators to use,” Swager says.

Moreover, the sensors each cost about a nickel to make; roughly 4 million can be made from about 1 gram of the carbon nanotube materials. “You really can’t make anything cheaper,” Swager says. “That’s a way of getting distributed sensing into many people’s hands.”

The paper’s other co-authors are from Swager’s lab: Shinsuke Ishihara, a postdoc who is also a member of the International Center for Materials Nanoarchitectonics at the National Institute for Materials Science, in Japan; and PhD students Joseph Azzarelli and Markrete Krikorian.

Wrapping nanotubes

In recent years, Swager’s lab has developed other inexpensive, wireless sensors, called chemiresistors, that have detected spoiled meat and the ripeness of fruit, among other things [go to the end of this post for links to previous posts about Swager’s work]. All are designed similarly, with carbon nanotubes that are chemically modified, so their ability to carry an electric current changes when exposed to a target chemical.

This time, the researchers designed sensors highly sensitive to “electrophilic,” or electron-loving, chemical substances, which are often toxic and used for chemical weapons.

To do so, they created a new type of metallo-supramolecular polymer, a material made of metals binding to polymer chains. The polymer acts as an insulation, wrapping around each of the sensor’s tens of thousands of single-walled carbon nanotubes, separating them and keeping them highly resistant to electricity. But electrophilic substances trigger the polymer to disassemble, allowing the carbon nanotubes to once again come together, which leads to an increase in conductivity.

In their study, the researchers drop-cast the nanotube/polymer material onto gold electrodes, and exposed the electrodes to diethyl chlorophosphate, a skin irritant and reactive simulant of nerve gas. Using a device that measures electric current, they observed a 2,000 percent increase in electrical conductivity after five seconds of exposure. Similar conductivity increases were observed for trace amounts of numerous other electrophilic substances, such as thionyl chloride (SOCl2), a reactive simulant in choking agents. Conductivity was significantly lower in response to common volatile organic compounds, and exposure to most nontarget chemicals actually increased resistivity.

Creating the polymer was a delicate balancing act but critical to the design, Swager says. As a polymer, the material needs to hold the carbon nanotubes apart. But as it disassembles, its individual monomers need to interact more weakly, letting the nanotubes regroup. “We hit this sweet spot where it only works when it’s all hooked together,” Swager says.

Resistance is readable

To build their wireless system, the researchers created an NFC tag that turns on when its electrical resistance dips below a certain threshold.

Smartphones send out short pulses of electromagnetic fields that resonate with an NFC tag at radio frequency, inducing an electric current, which relays information to the phone. But smartphones can’t resonate with tags that have a resistance higher than 1 ohm.

The researchers applied their nanotube/polymer material to the NFC tag’s antenna. When exposed to 10 parts per million of SOCl2 for five seconds, the material’s resistance dropped to the point that the smartphone could ping the tag. Basically, it’s an “on/off indicator” to determine if toxic gas is present, Swager says.

According to the researchers, such a wireless system could be used to detect leaks in Li-SOCl2 (lithium thionyl chloride) batteries, which are used in medical instruments, fire alarms, and military systems.

The next step, Swager says, is to test the sensors on live chemical agents, outside of the lab, which are more dispersed and harder to detect, especially at trace levels. In the future, there’s also hope for developing a mobile app that could make more sophisticated measurements of the signal strength of an NFC tag: Differences in the signal will mean higher or lower concentrations of a toxic gas. “But creating new cell phone apps is a little beyond us right now,” Swager says. “We’re chemists.”

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

Ultratrace Detection of Toxic Chemicals: Triggered Disassembly of Supramolecular Nanotube Wrappers by Shinsuke Ishihara, Joseph M. Azzarelli, Markrete Krikorian, and Timothy M. Swager. J. Am. Chem. Soc., Article ASAP DOI: 10.1021/jacs.6b03869 Publication Date (Web): June 23, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Here are links to other posts about Swager’s work featured here previously:

Carbon nanotubes sense spoiled food (April 23, 2015 post)

Smart suits for US soldiers—an update of sorts from the Lawrence Livermore National Laboratory (Feb. 25, 2014 post)

Come, see my etchings … they detect poison gases (Oct. 9, 2012 post)

Soldiers sniff overripe fruit (May 1, 2012 post)

Nano and food discussion for beginners

I try to make sure there are a range of posts here for various levels of ‘nanotechnology sophistication’ but over time I’ve given less attention to ‘beginner’ posts, i.e., pieces where nanotechnology basics are explained as best as possible. This is largely due to concerns about repetition; I mean, how many times do you want to read that nano means one billionth?

In that spirit, this June 22, 2016 news item on Nanowerk about food and nanotechnology provides a good entry piece that is not terribly repetitive,

Every mouthful of food we eat is teeming with chemical reactions. Adding ingredients and cooking helps us control these reactions and makes the food taste better and last longer. So what if we could target food at the molecular level, sending in specially designed particles to control reactions even more tightly? Well, this is exactly what scientists are trying to do and it has already produced some impressive results – from food that tastes salty without the health risks of adding salt, to bread that contains healthy fish oil but without any fishy aftertaste.

But while this nanotechnology could significantly enhance our food, it also raises big questions about safety. We only have to look at the strong reaction against genetically modified foods to see how important this issue is. How can we ensure that nanotechnology in food will be different? Will our food be safe? And will people accept these new foods?

Nanotechnology is an emerging technology that creates and uses materials and particles at the scale of a nanometre, one billionth of a metre. To get an understanding of just how small this is, if you imagine a nanoparticle was the size of a football then an animal like a sheep would be as big as our planet.

Working with such small particles allows us to create materials and products with improved properties, from lighter bicycles and more durable beer bottles to cosmetic creams with better absorption and toothpastes that stop bacteria from growing. Being able to change a material’s properties means nanotechnology can help create many innovative food products and applications that change the way we process, preserve and package foods.

For example, nanotechnology can be used for “smart” packaging that can monitor the condition of foods while they are stored and transported. When foods are contaminated or going off, the sensors on the packaging pick up gases produced by bacteria and change colour to alert anyone who wants to eat the food.

A June 22, 2016 essay by Seda Erdem (University of Stirling; UK) on The Conversation, which originated the news item, provides more information in this excerpt,

Silver is already used in healthcare products such as dental equipment for its antibacterial properties. Nano-sizing silver particles improves their ability to kill bacteria because it increases the surface area of silver the bacteria are exposed to. Israeli scientists found that also coating packaging paper with nano-sized silver particles [also known as silver nanoparticles] combats bacteria such as E. coli and extends product shelf life.

Another example of nanotechnology’s use in food manufacturing is nano-encapsulation. This technology has been used to mask the taste and odour of tuna fish oil so that it could be used to enrich bread with heart healthy Omega-3 fatty acids. Fish oil particles are packed into a film coating that prevents the fish oil from reacting with oxygen and releasing its smell. The nanocapsules break open only when they reach the stomach so you can receive the health benefits of eating them without experiencing the odour.

Meanwhile, researchers at Nottingham University are looking into nanoscale salt particles than can increase the saltiness of food without increasing the amount of salt.

As with silver, breaking salt into smaller nanosize increases its surface area. This means its flavour can be spread more efficiently. The researchers claim this can reduce the salt content of standard crisps by 90% while keeping the same flavour.

Despite all the opportunities nanotechnology offers the food industry, most developments remain at the research and development stage. This slow uptake is due to the lack of information about the health and environmental impacts of the technology. For example, there is a concern whether ingested nanomaterials migrate to different parts of the body and accumulate in certain organs, such as liver and kidneys. This may then affect the functionality of these organs in the medium to long term.

Unknown risks

However, our knowledge of the risks associated with the use of nanomaterials is incomplete. These issues need to be better understood and addressed for the public to accept nanotechnology in food. This will also depend on the public’s understanding of the technology and how much they trust the food industry and the regulatory process watching over it.

Research has shown, for example, that consumers are more likely to accept nanotechnology when it is used in food packaging rather than in food processing. But nanotechnology in food production was seen as more acceptable if it increased the food’s health benefits, although consumers weren’t necessarily willing to pay more for this.

In our recent research, we found no strong attitudes towards or resistance to nanotechnology in food packaging in the UK. But there was still concern among a small group of consumers about the safety of foods. This shows how important it will be for food producers and regulators to provide consumers with the best available information about nanotechnology, including any uncertainties about the technology.

There you have it.

nanoIndEx publishes guidance document on assessing exposure to airborne nanomaterials

Lynn Bergeson’s June 21, 2016 posting on Nanotechnology Now announced a newly published guidance document from the European Union’s nanoIndEx,

… The guidance document summarizes the key findings of the project, and is intended to present the state of the art in personal exposure assessment for nanomaterials. The conclusions section states: “Unfortunately, many nanotoxicological studies have used excessive, unrealistically high doses of [manufactured nanomaterials] and it is therefore debatable what their findings mean for the lower real-world exposures of humans. Moreover, it is not clear how to establish realistic exposure dose testing in toxicological studies, as available data on occupational exposure levels are still sparse.” According to the guidance document, future studies should focus on the potentially adverse effects of low-level and realistic exposure to manufactured nanomaterials, especially through the use of exposure doses similar to those identified in environmental sampling.

You can find the 49pp PDF here or here. To whet your appetite, here’s a bit from the introduction to the “Exposure to Airborne Nanomaterials; A Guidance Document,”

… While human exposure to MNMs may in principle occur during any stage of the material’s lifecycle, it is most likely in workplaces, where these materials are produced or handled in large quantities or over long periods of time. Inhalation is considered as the most critical uptake route, because the small particles are able to penetrate deep into the lung and deposit in the gas exchange region. Inhalation exposure to airborne nanomaterials therefore needs to be assessed in view of worker protection.

Exposure to airborne particles can generally best be assessed by measuring the individual exposure in the personal breathing zone (PBZ) of an individual. The PBZ is defined as a 30 cm hemisphere around mouth and nose [2]. Measurements in the PBZ require instruments that are small and light-weight. The individual exposure specifically to MNMs [manufactured nanomaterials, sometimes also known as engineered nanomaterials or nanoparticles] has not been assessable in the past due to the lack of suitable personal samplers and/or monitors. Instead, most studies related to exposure to MNMs have been carried out using either bulky static measurement equipment or not nanospecific personal samplers. In recent years, novel samplers and monitors have been introduced that allow for an assessment of the more nanospecific personal exposure to airborne MNMs. In the terminology used in nanoIndEx, samplers are devices that collect particles on a substrate, e.g. a filter
of flat surface, for subsequent analysis, whereas monitors are real-time instruments that deliver
information on the airborne concentrations with high time resolution. Scientifically sound investigations on the accuracy, comparability and field applicability of these novel samplers and monitors had been lacking. … (p. 4 print; p. 6 PDF)

There’s also a brief description of the nanoindEX project in the Introduction,

The three-year project started on June 1st, 2013, and has been funded under the frame of SIINN, the ERA-NET [European Research Area Network] for a Safe Implementation of Innovative Nanoscience and Nanotechnology [SINN]. The aim of the project was to scrutinise the instrumentation available for personal exposure assessment concerning their field readiness and usability in order to use this information to generate reliable data on personal exposure in real workplaces and to eventually widely distribute the findings among the interested public. This Guidance Document you are holding in your hands summarises the key findings of the project. (p. 5 print; p. 7 PDF)

As I understand it, the area of most concern where nanotoxicology is concerned would be inhalation of nanoparticles into the lungs as the body has fewer protections in the respiratory tract than it has elsewhere, e.g. skin or digestive system.

Nanotechnology Molecular Tagging for sniffing out explosives

A nifty technology for sniffing out explosives is described in a June 22, 2016 news item in Government Security News magazine. I do think they might have eased up on the Egypt Air disaster reference and the implication that it might have been avoided with the use of this technology,

The crash of an Egypt Air Flight 804 recently again raised concerns over whether a vulnerability in pre-flight security has led to another deadly terrorist attacks. Officials haven’t found a cause for the crash yet, but news reports indicate that officials believe either a bomb or fire are what brought the plane down [link included from press release].

Regardless of the cause, the Chief Executive Officer of British-based Ancon Technologies said that the incident shows the compelling need for more versatile and affordable explosive detection technology.

“There are still too many vulnerabilities in transportation systems around the world,” said CEO Dr. Robert Muir. “That’s why our focus has been on developing explosive detection technology that is highly efficient, easily deployable and economically priced.”

A June 21, 2015 Ancon Technologies press release on PR Web, which originated the news item, describes the technology in a little more detail,

Using nanotechnology to scan sensitive vapour readings, Ancon Technologies has developed unique security devices with exception sensitivity to detect explosive chemicals and materials. Called Nanotechnology Molecular Tagging, the technology is used to look for specific molecular markers that are emitted from the chemicals used in explosive compounds. An NMT device can then be programmed to look for these compounds and gauge concentrations.

“The result is unprecedented sensitivity for a device that is portable and versatile,” Dr. Muir said. “The technology is also highly selective, meaning it can distinguish the molecules is testing for against the backdrop of other chemicals and readings in the air.”

If terrorism is responsible for the crash of the Egypt Air flight on route to Cairo from Paris’ Charles de Gaulle Airport, the incident further shows the need for heightened screening processes, Muir said. Concerns about air travel’s vulnerabilities to terrorism were further raised in October when a Russian plane flying out of Egypt crashed in what several officials believe was a terrorist bombing.

Both cases show the need for improved security measures in airports around the world, especially those related to early explosive detection, Muir said. CNN reported that the Egypt Air crash would likely generate even more attention to airport security while Egypt has already been investing in new security measures following the October attack.

“An NMT device can bring laboratory-level sensitivity to the airport screening procedure, adding another level of safety in places where it’s needed most,” Muir said. “By being able to detect a compound at concentrations as small as a single molecule, NMT can pinpoint a threat and provide security teams with the early warning they need.”

The NMT device’s sensitivity and accuracy can also help balance another concern with airport security: long waits. Already, the Transportation Security Agency is coming under fire this summer for extended airport security screening lines, reports USA Today.

“An NMT device can produce results from test samples in minutes, meaning screenings can proceed at a reasonable pace without jeopardizing security,” Muir said.

Ancon Technologies has working arrangements with military and security agencies in both the United Kingdom and the United States, Muir said, following a recent round of investments. The company is headquartered in Canterbury, Kent and has an office in the U.S. in Bloomington, Minnesota.

So this is a sensing device and I believe this particular type can also be described as an artificial nose.

International nano news bits: Belarus and Vietnam

I have two nano news bits, one concerning Belarus and the other concerning Vietnam.

Belarus

From a June 21, 2016 news item on Belarus News,

In the current five-year term Belarus will put efforts into developing robot technology, nano and biotechnologies, medical industry and a number of other branches of the national economy that can make innovative products, BelTA learned from Belarusian Economy Minister Vladimir Zinovsky on 21 June [2016].

The Minister underlined that the creation of new kinds of products, the development of conventional industries will produce their own results in economy and will allow securing a GDP growth rate as high as 112-115% in the current five-year term.

The last time Belarus was mentioned here was in a June 24, 2014 posting (scroll down about 25% of the way to see Belarus mentioned) about the European Union’s Graphene Flagship programme and new partners in the project. There was also a March 6, 2013 posting about Belarus and a nanotechnology partnership with Indonesia. (There are other mentions but those are the most recent.)

Vietnam

Vietnam has put into operation its first bio-nano production plant. From a June 21, 2016 news item on vietnamnet,

The Vietlife biological nano-plant was officially put into operation on June 20 [2016] at the North Thang Long Industrial Park in Hanoi.

It is the first plant producing biological nano-products developed entirely by Vietnamese scientists with a successful combination of traditional medicine, nanotechnology and modern drugs.

At the inauguration, Professor, Academician Nguyen Van Hieu, former president of Vietnam Academy of Science and Technology, who is the first to bring nanotechnology to Vietnam, reviewed the milestones of nanotechnology around the world and in the country.

In 2000, former US President Bill Clinton proposed American scientists research and develop nanotechnology for the first time.

Japan and the Republic of Korea then began developing the new technology.

Just two years later, in 2002, Vietnamese scientists also recommended research on nanotechnology and got the approval from the Party and State.

Academician Hieu said that Vietnam does not currently use nanotechnology to manufacture flat-screen TVs or smartphones. However, in Southeast Asia Vietnam has pioneered the research and successful applications of nanotechnology in production of probiotics combined with traditional medicine in health care, opening up a new potential science research in Vietnam.

Cam Ha JSC and scientists at the Vietnam Academy of Science and Technology have co-operated with a number of laboratories in the US, Australia and Japan to study and successfully develop a bio-nano production line in sync with diverse technologies.

Vietlife is the first plant to combine traditional medicine with nanotechnology and modern medicine. It consists of three technological lines: NANO MICELLE No. 1, 2 and 3; a NANO SOL-GEL chain; a packaging line, and a bio-nano research centre.

Nghia [Prof. Dr. Nguyen Duc Nghia, former deputy director of the Chemistry Institute under the Vietnam Academy of Science and Technology] said the factory has successfully produced some typical bio products, including Nanocurcumin NDN22+ from Vietnamese turmeric by nano micelle and Nano Sol-Gel methods. Preclinical experiment results indicate that at a concentration of about 40ppm, NDN22+ solution can kill 100% of rectum cancer tumors and prostate tumor cells within 72 hours. [emphasis mine]

In addition, it also manufactures other bio-nano products like Nanorutin from luscious trees and Nanolycopen from gac (Momordica cochinchinensis) oil.

Unfortunately, this news item does not include links to the research supporting the claims regarding nanocurcumin NDN22+. Hopefully, I will stumble across it soon.

Lungs: EU SmartNanoTox and Pneumo NP

I have three news bits about lungs one concerning relatively new techniques for testing the impact nanomaterials may have on lungs and two concerning developments at PneumoNP; the first regarding a new technique for getting antibiotics to a lung infected with pneumonia and the second, a new antibiotic.

Predicting nanotoxicity in the lungs

From a June 13, 2016 news item on Nanowerk,

Scientists at the Helmholtz Zentrum München [German Research Centre for Environmental Health] have received more than one million euros in the framework of the European Horizon 2020 Initiative [a major European Commission science funding initiative successor to the Framework Programme 7 initiative]. Dr. Tobias Stöger and Dr. Otmar Schmid from the Institute of Lung Biology and Disease and the Comprehensive Pneumology Center (CPC) will be using the funds to develop new tests to assess risks posed by nanomaterials in the airways. This could contribute to reducing the need for complex toxicity tests.

A June 13, 2016 Helmholtz Zentrum München (German Research Centre for Environmental Health) press release, which originated the news item, expands on the theme,

Nanoparticles are extremely small particles that can penetrate into remote parts of the body. While researchers are investigating various strategies for harvesting the potential of nanoparticles for medical applications, they could also pose inherent health risks*. Currently the hazard assessment of nanomaterials necessitates a complex and laborious procedure. In addition to complete material characterization, controlled exposure studies are needed for each nanomaterial in order to guarantee the toxicological safety.

As a part of the EU SmartNanoTox project, which has now been funded with a total of eight million euros, eleven European research partners, including the Helmholtz Zentrum München, want to develop a new concept for the toxicological assessment of nanomaterials.

Reference database for hazardous substances

Biologist Tobias Stöger and physicist Otmar Schmid, both research group heads at the Institute of Lung Biology and Disease, hope that the use of modern methods will help to advance the assessment procedure. “We hope to make more reliable nanotoxicity predictions by using modern approaches involving systems biology, computer modelling, and appropriate statistical methods,” states Stöger.

The lung experts are concentrating primarily on the respiratory tract. The approach involves defining a representative selection of toxic nanomaterials and conducting an in-depth examination of their structure and the various molecular modes of action that lead to their toxicity. These data are then digitalized and transferred to a reference database for new nanomaterials. Economical tests that are easy to conduct should then make it possible to assess the toxicological potential of these new nanomaterials by comparing the test results s with what is already known from the database. “This should make it possible to predict whether or not a newly developed nanomaterial poses a health risk,” Otmar Schmid says.

* Review: Schmid, O. and Stoeger, T. (2016). Surface area is the biologically most effective dose metric for acute nanoparticle toxicity in the lung. Journal of Aerosol Science, DOI:10.1016/j.jaerosci.2015.12.006

The SmartNanoTox webpage is here on the European Commission’s Cordis website.

Carrying antibiotics into lungs (PneumoNP)

I received this news from the European Commission’s PneumoNP project (I wrote about PneumoNP in a June 26, 2014 posting when it was first announced). This latest development is from a March 21, 2016 email (the original can be found here on the How to pack antibiotics in nanocarriers webpage on the PneumoNP website),

PneumoNP researchers work on a complex task: attach or encapsulate antibiotics with nanocarriers that are stable enough to be included in an aerosol formulation, to pass through respiratory tracts and finally deliver antibiotics on areas of lungs affected by pneumonia infections. The good news is that they finally identify two promising methods to generate nanocarriers.

So far, compacting polymer coils into single-chain nanoparticles in water and mild conditions was an unsolved issue. But in Spain, IK4-CIDETEC scientists developed a covalent-based method that produces nanocarriers with remarkable stability under those particular conditions. Cherry on the cake, the preparation is scalable for more industrial production. IK4-CIDETEC patented the process.

Fig.: A polymer coil (step 1) compacts into a nanocarrier with cross-linkers (step 2). Then, antibiotics get attached to the nanocarrier (step 3).

Fig.: A polymer coil (step 1) compacts into a nanocarrier with cross-linkers (step 2). Then, antibiotics get attached to the nanocarrier (step 3).

At the same time, another route to produce lipidic nanocarriers have been developed by researchers from Utrecht University. In particular, they optimized the method consisting in assembling lipids directly around a drug. As a result, generated lipidic nanocarriers show encouraging stability properties and are able to carry sufficient quantity of antibiotics.

Fig.: On presence of antibiotics, the lipidic layer (step 1) aggregates the the drug (step 2) until the lipids forms a capsule around the antibiotics (step 3).

Fig.: On presence of antibiotics, a lipidic layer (step 1) aggregates the drug (step 2) until the lipids forms a capsule around antibiotics (step 3).

Assays of both polymeric and lipidic nanocarriers are currently performed by ITEM Fraunhofer Institute in Germany, Ingeniatrics Tecnologias in Spain and Erasmus Medical Centre in the Netherlands. Part of these tests allows to make sure that the nanocarriers are not toxic to cells. Other tests are also done to verify that the efficiency of antibiotics on Klebsiella Pneumoniae bacteria when they are attached to nanocarriers.

A new antibiotic for pneumonia (PneumoNP)

A June 14, 2016 PneumoNP press release (received via email) announces work on a promising new approach to an antibiotic for pneumonia,

The antimicrobial peptide M33 may be the long-sought substitute to treat difficult lung infections, like multi-drug resistant pneumonia.

In 2013, the European Respiratory Society predicted 3 millions cases of pneumonia in Europe every year [1]. The standard treatment for pneumonia is an intravenous administration of a combination of drugs. This leads to the development of antibiotic resistance in the population. Gradually, doctors are running out of solutions to cure patients. An Italian company suggests a new option: the M33 peptide.

Few years ago, the Italian company SetLance SRL decided to investigate the M33 peptide. The antimicrobial peptide is an optimized version of an artificial peptide sequence selected for its efficacy and stability. So far, it showed encouraging in-vitro results against multidrug-resistant Gram-negative bacteria, including Klebsiella Pneumoniae. With the support of EU funding to the PneumoNP project, SetLance SRL had the opportunity to develop a new formulation of M33 that enhances its antimicrobial activity.

The new formulation of M33 fights Gram-negative bacteria in three steps. First of all, the M33 binds with the lipopolysaccharides (LPS) on the outer membrane of bacteria. Then, the molecule forms a helix and finally disrupts the membrane provoking cytoplasm leaking. The peptide enabled up to 80% of mices to survive Pseudomonas Aeruginosa-based lung infections. Beyond these encouraging results, toxicity to the new M33 formulation seems to be much lower than antimicrobial peptides currently used in clinical practice like colistin [2].

Lately, SetLance scaled-up the synthesis route and is now able to produce several hundred milligrams per batch. The molecule is robust enough for industrial production. We may expect this drug to go on clinical development and validation at the beginning of 2018.

[1] http://www.erswhitebook.org/chapters/acute-lower-respiratory-infections/pneumonia/
[2] Ceccherini et al., Antimicrobial activity of levofloxacin-M33 peptide conjugation or combination, Chem Med Comm. 2016; Brunetti et al., In vitro and in vivo efficacy, toxicity, bio-distribution and resistance selection of a novel antibacterial drug candidate. Scientific Reports 2016

I believe all the references are open access.

Brief final comment

The only element linking these news bits together is that they concern the lungs.

Introducing the LIFE project NanoMONITOR

I believe LIFE in the project title refers to life cycle. Here’s more from a June 9, 2016 news item from Nanowerk (Note: A link has been removed),

The newly started European Commission LIFE project NanoMONITOR addresses the challenges of supporting the risk assessment of nanomaterials under REACH by development of a real-time information and monitoring system. At the project’s kickoff meeting held on the 19th January 2016 in Valencia (Spain) participants discussed how this goal could be achieved.

Despite the growing number of engineered nanomaterials (ENMs) already available on the market and in contract to their benefits the use, production, and disposal of ENMs raises concerns about their environmental impact.

A REACH Centre June 8, 2016 press release, which originated the news item, expands on the theme,

Within this context, the overall aim of LIFE NanoMONITOR is to improve the use of environmental monitoring data to support the implementation of REACH regulation and promote the protection of human health and the environment when dealing with ENMs. Within the EU REACH Regulation, a chemical safety assessment report, including risk characterisation ratio (RCR), must be provided for any registered ENMs. In order to address these objectives, the project partners have developed a rigorous methodology encompassing the following aims:

  • Develop a novel software application to support the acquisition, management and processing of data on the concentration of ENMs.
  • Develop an on-line environmental monitoring database (EMD) to support the sharing of information.
  • Design and develop a proven monitoring station prototype for continuous monitoring of particles below 100 nm in air (PM0.1).
  • Design and develop standardized sampling and data analysis procedures to ensure the quality, comparability and reliability of the monitoring data used for risk assessment.
  • Support the calculation of the predicted environmental concentration (PEC) of ENMs in the context of REACH.

Throughout the project’s kick off meeting, participants discussed the status of the research area, project goals, and expectations of the different stakeholders with respect to the project outcome.

The project has made this graphic available,

LIFE_NanoMONITOR

You can find the LIFE project NanoMONITOR website here.

June 2016: time for a post on nanosunscreens—risks and perceptions

In the years since this blog began (2006), there’ve been pretty regular postings about nanosunscreens. While there are always concerns about nanoparticles and health, there has been no evidence to support a ban (personal or governmental) on nanosunscreens. A June 2016 report  by Paul FA Wright (full reference information to follow) in an Australian medical journal provides the latest insights on safety and nanosunscreens. Wright first offers a general introduction to risks and nanomaterials (Note: Links have been removed),

In reality, a one-size-fits-all approach to evaluating the potential risks and benefits of nanotechnology for human health is not possible because it is both impractical and would be misguided. There are many types of engineered nanomaterials, and not all are alike or potential hazards. Many factors should be considered when evaluating the potential risks associated with an engineered nanomaterial: the likelihood of being exposed to nanoparticles (ranging in size from 1 to 100 nanometres, about one-thousandth of the width of a human hair) that may be shed by the nanomaterial; whether there are any hotspots of potential exposure to shed nanoparticles over the whole of the nanomaterial’s life cycle; identifying who or what may be exposed; the eventual fate of the shed nanoparticles; and whether there is a likelihood of adverse biological effects arising from these exposure scenarios.1

The intrinsic toxic properties of compounds contained in the nanoparticle are also important, as well as particle size, shape, surface charge and physico-chemical characteristics, as these greatly influence their uptake by cells and the potential for subsequent biological effects. In summary, nanoparticles are more likely to have higher toxicity than bulk material if they are insoluble, penetrate biological membranes, persist in the body, or (where exposure is by inhalation) are long and fibre-like.1 Ideally, nanomaterial development should incorporate a safety-by-design approach, as there is a marketing edge for nano-enabled products with a reduced potential impact on health and the environment.1

Wright also covers some of nanotechnology’s hoped for benefits but it’s the nanosunscreen which is the main focus of this paper (Note: Links have been removed),

Public perception of the potential risks posed by nanotechnology is very different in certain regions. In Asia, where there is a very positive perception of nanotechnology, some products have been marketed as being nano-enabled to justify charging a premium price. This has resulted in at least four Asian economies adopting state-operated, user-financed product testing schemes to verify nano-related marketing claims, such as the original “nanoMark” certification system in Taiwan.4

In contrast, the negative perception of nanotechnology in some other regions may result in questionable marketing decisions; for example, reducing the levels of zinc oxide nanoparticles included as the active ingredient in sunscreens. This is despite their use in sunscreens having been extensively and repeatedly assessed for safety by regulatory authorities around the world, leading to their being widely accepted as safe to use in sunscreens and lip products.5

Wright goes on to describe the situation in Australia (Note: Links have been removed),

Weighing the potential risks and benefits of using sunscreens with UV-filtering nanoparticles is an important issue for public health in Australia, which has the highest rate of skin cancer in the world as the result of excessive UV exposure. Some consumers are concerned about using these nano-sunscreens,6 despite their many advantages over conventional organic chemical UV filters, which can cause skin irritation and allergies, need to be re-applied more frequently, and are absorbed by the skin to a much greater extent (including some with potentially endocrine-disrupting activity). Zinc oxide nanoparticles are highly suitable for use in sunscreens as a physical broad spectrum UV filter because of their UV stability, non-irritating nature, hypo-allergenicity and visible transparency, while also having a greater UV-attenuating capacity than bulk material (particles larger than 100 nm in diameter) on a per weight basis.7

Concerns about nano-sunscreens began in 2008 with a report that nanoparticles in some could bleach the painted surfaces of coated steel.8 This is a completely different exposure situation to the actual use of nano-sunscreen by people; here they are formulated to remain on the skin’s surface, which is constantly shedding its outer layer of dead cells (the stratum corneum). Many studies have shown that metal oxide nanoparticles do not readily penetrate the stratum corneum of human skin, including a hallmark Australian investigation by Gulson and co-workers of sunscreens containing only a less abundant stable isotope of zinc that allowed precise tracking of the fate of sunscreen zinc.9 The researchers found that there was little difference between nanoparticle and bulk zinc oxide sunscreens in the amount of zinc absorbed into the body after repeated skin application during beach trials. The amount absorbed was also extremely small when compared with the normal levels of zinc required as an essential mineral for human nutrition, and the rate of skin absorption was much lower than that of the more commonly used chemical UV filters.9 Animal studies generally find much higher skin absorption of zinc from dermal application of zinc oxide sunscreens than do human studies, including the meticulous studies in hairless mice conducted by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) using both nanoparticle and bulk zinc oxide sunscreens that contained the less abundant stable zinc isotope.10 These researchers reported that the zinc absorbed from sunscreen was distributed throughout several major organs, but it did not alter their total zinc concentrations, and that overall zinc homeostasis was maintained.10

He then discusses titanium dioxide nanoparticles (also used in nanosunscreens, Note: Links have been removed),

The other metal oxide UV filter is titanium dioxide. Two distinct crystalline forms have been used: the photo-active anatase form and the much less photo-active rutile form,7 which is preferable for sunscreen formulations. While these insoluble nanoparticles may penetrate deeper into the stratum corneum than zinc oxide, they are also widely accepted as being safe to use in non-sprayable sunscreens.11

Investigation of their direct effects on human skin and immune cells have shown that sunscreen nanoparticles of zinc oxide and rutile titanium dioxide are as well tolerated as zinc ions and conventional organic chemical UV filters in human cell test systems.12 Synchrotron X-ray fluorescence imaging has also shown that human immune cells break down zinc oxide nanoparticles similar to those in nano-sunscreens, indicating that immune cells can handle such particles.13 Cytotoxicity occurred only at very high concentrations of zinc oxide nanoparticles, after cellular uptake and intracellular dissolution,14 and further modification of the nanoparticle surface can be used to reduce both uptake by cells and consequent cytotoxicity.15

The ongoing debate about the safety of nanoparticles in sunscreens raised concerns that they may potentially increase free radical levels in human skin during co-exposure to UV light.6 On the contrary, we have seen that zinc oxide and rutile titanium dioxide nanoparticles directly reduce the quantity of damaging free radicals in human immune cells in vitro when they are co-exposed to the more penetrating UV-A wavelengths of sunlight.16 We also identified zinc-containing nanoparticles that form immediately when dissolved zinc ions are added to cell culture media and pure serum, which suggests that they may even play a role in natural zinc transport.17

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

Potential risks and benefits of nanotechnology: perceptions of risk in sunscreens by Paul FA Wright. Med J Aust 2016; 204 (10): 369-370. doi:10.5694/mja15.01128 Published June 6, 2016

This paper appears to be open access.

The situation regarding perceptions of nanosunscreens in Australia was rather unfortunate as I noted in my Feb. 9, 2012 posting about a then recent government study which showed that some Australians were avoiding all sunscreens due to fears about nanoparticles. Since then Friends of the Earth seems to have moderated its stance on nanosunscreens but there is a July 20, 2010 posting (includes links to a back-and-forth exchange between Dr. Andrew Maynard and Friends of the Earth representatives) which provides insight into the ‘debate’ prior to the 2012 ‘debacle’. For a briefer overview of the situation you could check out my Oct. 4, 2012 posting.