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NanoSustain published four case studies: zinc oxide, titanium dioxide, carbon nanotubes, and nanocellulose

Tuesday, May 21st, 2013

A May 17, 2013 news item on Nanowerk highlight a European Commission-funded project, NanoSustain and its publication of a fact sheet and four case studies,,

NanoSustain, a €2.5 million NMP small collaborative project (2010-2013) funded by the European Union under FP7, has published a fact sheet and four case studies addressing these issues.

How do nanotechnology-based products impact human health and the environment?
Can they be recycled?
Can they be safely disposed of?
How can you find out?

The March 20, 2013 NanoSustain news release, which originated the news item, goes on to explain,

… the EC-funded NanoSustain project has been developing new sustainable solutions through an investigation of the life-cycle of nanotechnology-based products, in particular the physical and chemical characteristics of materials, hazard and exposure aspects, and end-of-life disposal or recycling to determine the fate and impact of nanomaterials.

A summary of the different materials and products tested within NanoSustain:

• Case Study #1: Titanium dioxide for paints
• Case Study #2: Zinc oxide for glazing products
• Case Study #3: Carbon nanotubes epoxy resins for plastics
- for structural or electrical/antistatic applications
• Case Study #4: Nanocellulose for advanced paper applications

Information about the individual experimental approaches

Descriptions of the different techniques developed

How these techniques have been successfully applied in physical-chemical characterisation; life-cycle analysis; final disposal; recycling.

Getting access to the case case studies and the fact sheet requires filling out a form but once you’ve done that you get instant access to the materials.

Here’s some information from EuroSustain’s fact sheet,

Factsheets

Analytical Techniques

Development of sustainable solutions for nanotechnology-based products based on hazard characterization and LCA1 The primary goal of the NanoSustain project is to develop new technical solutions for the sustainable design and use, recycling and final treatment of selected nanotechnology-based products.

To achieve this the project has the following objectives: 1) to assess the hazard of selected nanomaterials based on a comprehensive data survey and generation concerning their physicochemical (PC) and toxicological properties, exposure probabilities, etc., and the adaptation, evaluation, validation and use of existing analytical, testing and life-cycle assessment (LCA) methods; 2) to assess the impact of selected products during their life cycle in relation to material and energy flows (LCA); 3) to assess possible exposure routes and risks associated with the handling of these materials, their transformation and final fate; and 4) to explore the feasibility and sustainability of new technical solutions for end-of=life processes, such as reuse/recycling, final treatment or disposal.

…

Within NanoSustain an assessment has been made of the PC properties, exposure and toxicity, energy and material inputs and outputs at relevant stages of a material or product’s life-cycle. This means: material production, processing, manufacturing, use, transportation, and end-of-life (recycling/disposal). At each stage potential risks to human health and the environment have also been assessed, through a number of experimental models and test systems using materials that would be expected to be released from products containing nanomaterials.

Four nanomaterials were investigated that either already feature in commercial products or are expected to be commercialized on a large scale: titanium dioxide (TiO2) in paint, zinc oxide (ZnO) as a coating for glass, multi-walled carbon nanotubes (MWCNT) in epoxy resins, and nanocellulose in paper.

Detailed information on the nanomaterials have been summarized in internal project material datasheets (MDS), and will be made available as part of peer-reviewed publications on release studies and toxicological investigations. [emphases mine]

Having looked at the four case studies, each of which is two pages, I would describe them as teasers. There’s not a lot of information in them as to the results of the testing which makes sense when you see that they will be publishing in various publications.

I find the inclusion of titanium dioxide, zinc oxide and carbon nanotubes for life-cycle assessments easily understandable as they  have been integrated into many consumer products. However, it’s my understanding that nanocellulose has not reached that level of product integration. Still, given the number of times I’ve been told this is a ‘safe’ product, it’s interesting to see what NanoSustain has to say about its toxicity (from the NanoSustain’s nanocellulose case study),

Work in NanoSustain has provided new data and information on the physicochemical properties, potential human and environmental hazard and risk associated with relevant stages of the life-cycle of nanocellulose based products as well as on the overall energy and material input/output that may happen during manufacturing, use and disposal. Initial results indicate that the nanocellulose degrades efficiently under standard composting conditions, but does not in aquatic environments. Furthermore nanocellulose does not demonstrate any ecotoxicity. Unfortunately nanocellulose forms a gel when suspended in media for inhalation studies, and so no toxicology experiments could be performed (as for the other engineered nanomaterials studied in NanoSustain). Final results will be made available once published in peer-reviewed journals.

I have written many times about nanocellulose, a topic featuring some interesting and confusing nomenclature and taking this opportunity to highlight a couple of responses from folks who took the time to clarify things for me (from my Aug. 2, 2012 posting),

KarenS says:

Hi Maryse!

From my understanding, nanocrystaline cellulose (NCC), cellulose nanocrystals (CNC), cellulose whiskers (CW) and cellulose nanowhiskers (CNW) are all the same stuff: cylindrical rods of crystalline cellulose (diameter: 5-10 nm; length: 20-1000 nm). Cellulose nanofibers or nanofibrils (CNF), on the contrary, are less crystalline and are in the form of long fibers (diameter: 20-50 nm; length: up to several micrometers).

There is still a lot of confusion on the nomenclature of cellulose nanoparticles, but nice explanations (and pictures!) are given here (and also in other papers from the same conference):

http://www.tappi.org/Downloads/Conference-Papers/2012/12NANO/12NANO49.aspx

and there’s this from my Sept. 26, 2012 posting,

Gary Chinga Carrasco says:

The definition of cellulose nanofibrils as “diameter: 20-50 nm; length: up to several micrometers)” is somewhat simplified. For terminology on MFC terms you may want to take a look at: http://www.nanoscalereslett.com/content/6/1/417

Bringing this piece back to where I started, I look forward to seeing the NanoSustain case studies published with more details in the future.

Note: Since the folks at NanoSustain are likely using their form to collect data, I’m not linking back to the factsheet or nanocellulose case study as I would usually. So, if you want to look at the material, you do need to register via the form.

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Self-cleaning schools

Wednesday, April 24th, 2013

I’m all for self-cleaning, which is why this Apr. 19, 2013 news item on Azonano caught my attention,

“We’re always trying to create a cleaner environment for students and teachers in an effort to reduce absenteeism and the associated costs,” says Dr. Henry Kiernan, Superintendent with the Bellmore-Merrick School District in New York. “The NanoTouch® products provide an additional benefit of communicating our commitment, which plays an important role in our relationship with parents.”

Bellmore-Merrick has installed facility touch points, including door push pads and handle wraps, on all bathroom doors in an initial 5 high schools. Other schools have brought the portable NanoSeptic surfaces into the classroom in the form of snack mats and desk mats.

“The pre-school students were fascinated by the snack mats and what they did. The children focused intently on keeping their snacks on the mat,” says Bonny Phillips , teacher at Liberty Christian Academy’s Early Learning Center. “It also provided an additional opportunity for learning about cleanliness and food handling.”

…

“Schools will continue to use one-time kill products like disinfectants, but NanoTouch enhances their cleaning efforts by working to eliminate even hard-to-kill microbes such as C. Diff, 24 hours a day, seven days a week,” says Mark Sisson , co-founder of NanoTouch. “And because alcohol based hand sanitizers pose a risk of fire around kids, NanoTouch products help to fill that void in schools.”

In today’s world of shrinking budgets, it’s sometimes difficult for schools to find funding for advanced technologies like NanoTouch, even when these products are inexpensive. However, some innovative thinking by a community bank has led to several classrooms being equipped with NanoSeptic snack mats. SelectBank, headquartered in Forest, Virginia, donates snack mats to area pre-schools and day cares as a way to give back to their community.

“When we can help area schools and children, and get some positive recognition from parents, that’s good for our community and for our business,” says Sherri Sackett , Marketing Manager at SelectBank.

And the parents at these schools are enthusiastically embracing the use of this new nanotechnology.

“We were very excited to hear that our son’s school has started using this new product,” says Robert Thomas, parent of a student at the Blue Ridge Montessori School. “Not only is this creating a cleaner classroom environment for our child, but it’s doing so in a healthier way, without poisons or heavy metals. And it’s such a unique product line that the school is considering selling the travel kits as a fundraiser.”

“NanoTouch is out to make the world a better and healthier place to live, work, and play. This is particularly important for sensitive populations, such as our youth,” says NanoTouch co-founder, Dennis Hackemeyer. “And, what can’t be understated is the communications ability of NanoTouch products to educate and change behavior.’”

It’s unusual these days to see a company market a ‘nanotechnology’ product by incorporating nano into  product names (e.g., NanoSeptic) and the company name (NanoTouch).

The NanoTouch website does not offer information about its management team (I was not able to find either co-founder although it is possible to find a listing for the company’s advisory board) nor is there much information about the technology. Here’s the best technology description I could find on the website, from the NanoTouch NanoSeptic versus other antimicrobials page,

NanoTouch products utilize several complex components which all work together. Our specialized fabrication process not only provides products that are durable enough to withstand routine cleaning, but also helps to accentuate the effectiveness of the antimicrobial ingredients and maximize the surface’s self-cleaning action. Our products contain widely used, harmless, “green” chemistry, which does not include diluted poisons or heavy metals. The antimicrobial technology we deploy, molecularly bonded on a nano-scale, provides a non-leaching, self-cleaning surface that constantly traps and kills bacteria, viruses and fungi through a catalytic oxidation process using available light.

…

All of these solutions approach the problem of bacteria, viruses and fungus by cleaning surfaces…which is absolutely necessary. NanoTouch is not meant to replace these methods, but instead, it is a perfect complement and another step in the reduction of germ transfer. While the these approaches clean a touchpoint or a person’s hand, contamination happens with the next contact or from airborne microbes. NanoTouch self-cleans…constantly killing bacteria, viruses and fungi.

I did find some details about the company co-founders on their respective  LinkedIn pages, Dennis Hackemeyer and Mark Sisson. Both men are associated with another company, KiteString, from the Our Approach page,

KiteString uses innovative technological solutions in the service of creative to achieve Marketing Relevance. Yes, we deliver traditional creative services like design, Web development, and direct mail, but we also provide technology-based marketing solutions and client service processes and systems that deliver measurably better operational efficiency, enhanced brand management, improved collaboration and greater marketing response rates.

I’m not sure what the KiteString description of their approach means but it looks like KiteString’s main activity is marketing. Anyway, that’s not so important given that my main interest is NanoTouch. For that matter, it would have been nice to have found more technical information. For example, How precisely is this product nanotechnology-enabled? Are there scientists working for or associated in some fashion with NanoTouch? What kind of testing has the product undergone? These are a few of the questions that leap to mind.

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Ingesting nano silver: a double-blind study

Tuesday, April 23rd, 2013

American Biotech Labs (ABL) has released publicity about an intriguing study on ingesting nano silver. From the Apr. 23, 2013 news item on Nanowerk,

The study included 3-, 7-, and 14-day exposures to American Biotech Labs 10-ppm (15 ml/day) silver solution in a double-blind, placebo controlled, cross-over phase design. Healthy volunteer subjects (36, 12 per each time-exposure), underwent complete metabolic, blood and platelet count, urinalysis tests, sputum hyperresponsiveness and inflammation evaluation, physical examinations, vital sign measurements, and magnetic resonance imaging of the chest and abdomen at baseline and at the end of each phase.

… Keith Moeller, A Managing Director at ABL. “… As a prelim to the study, I volunteered to be checked for silver deposition in my body, after 15+ years of almost daily usage as a supplement to help boost my immune system. No silver residue was found anywhere in my system. We are always working hard to gain knowledge about silver. Because of this, we have now amassed a library of more than 300 major reports, studies and test series, all completed on our nano-silver technology by more than 60 different universities, government/military labs, and private institutions.”

In conclusion the report stated, “The In-vivo oral exposure of a commercial 10-ppm silver nano-particle solution over 3-, 7-, and 14-day exposures does not exhibit clinically important changes in metabolic, hematologic, urine, vital sign changes, physical findings or imaging changes visualized by MRI.” …

Oddly, I cannot find where this study was published nor does the news release, which originated the news item, appear on the company website (as of 4 pm PDT April 23, 2013).

As for the study itself, which researchers ran the study? Was a third party contracted to run it? How did they ensure the study was double-blind? I gather this was not a randomized study.

They state specifically there were no urine changes. If the subjects are eliminating the silver, shouldn’t they be able to see that in the urine? If the silver accumulates in the body, how much is too much? Might it not take longer than 14 days to reach a toxic or dangerous stage?

Moeller’s personal endorsement is not really convincing as one assumes that as managing director of the company he has much to gain by encouraging people to ingest nano silver (ABL sells it as a health supplement). The same holds true regarding this study, which seems to have been run by the company itself.

As it stands, the study seems a bit sketchy but hopefully more details will emerge.

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Safe Work Australia’s two new reports, Europe’s Nanodevice project, and the UK’s HSE nanomaterials handling

Monday, April 1st, 2013

Over the last few weeks in March (2013), there was a sudden burst of health and safety reports and initiatives released by Safe Work Australia, the European Commission’s Nanodevice project, and the UK’s Health and Safety Executive, respectively.

According to a Mar. 19, 2013 news item on Nanowerk, Safe Work Australia released two reports (Note: Links have been removed),

Safe Work Australia Chair Ann Sherry AO today released two research reports examining nanotechnology work health and safety issues.

The reports: Investigating the emissions of nanomaterials from composites and other solid articles during machining process and Evaluation of potential safety (physicochemical) hazards associated with the use of engineered nanomaterials are part of a comprehensive program of work on nanotechnology safety managed by Safe Work Australia which started in 2007.

The March 18, 2013 Safe Work Australia media release, which originated the news item,  provides some information about the approaches and models being used to analyse and develop policies,

In releasing the reports Ms Sherry noted the perceived safety risks of nanomaterials and that a precautionary approach is being taken by the Commonwealth towards nanomaterials under the National Enabling Technologies Strategy.“

While the risk to human health and safety from a number of these materials and applications is low some nanomaterials are potentially more hazardous, for example carbon nanotubes,” Ms Sherry said.

“The National Industrial Chemicals Notification and Assessment Scheme (NICNAS) has recommended carbon nanotubes be classified as suspected carcinogens unless product-specific evidence suggests otherwise.”

Under the model Work Health and Safety (WHS) laws all duties which apply to the handling of materials and to technologies in general also apply to nanomaterials and nanotechnologies. Minimisation of exposure to nanomaterials at work is essential until there is sufficient data to rule out hazardous properties. Research has shown if conventional engineering controls are designed and maintained effectively, exposure to nanomaterials can be significantly reduced.

As a result of the findings of these reports Safe Work Australia will prepare guidance material on combustible dust hazards including nanomaterials.

Here’s more about the reports (from their respective webpages),

Investigating the emissions of nanomaterials from composites and other solid articles during machining processes

This report by CSIRO considers the potential health risk of emissions from machining processes.

The report finds that significant quantities of material, which can present health risk, are emitted from composites by high energy machining processes like cutting with an electric disc saw or band saw. If the composite contains a hazardous nanomaterial, the health risk from the dust may be higher. Lower energy processes like manual cutting will result in lower exposures and lower potential health risk.

Evaluation of potential safety hazards associated with the use of engineered nanomaterials

This report by Toxikos Pty Ltd examines safety hazards associated with engineered nanomaterials and the implications in regard to workers safety.

The report finds that dust clouds of some engineered nanomaterials could give rise to strong explosions if the dust cloud contains a high enough concentration of nanomaterials and if an ignition source is also present. The report gives examples of these. However in a well-managed workplace, emissions from nanotechnology processes will be very significantly below the minimum dust concentration needed for an explosion.

A Mar. 20, 2013 news item on Nanowerk focused on the European Commission’s Nanodevice project,

European researchers in the Nanodevice project are investigating the safety aspects of nanomaterial production. Their plan laid down in 2009 was to develop new concepts, reliable methods and portable devices for detecting, analysing and monitoring airborne ENMs in the workplace. The latest feedback from the team suggests the project has delivered on its promise.

The project has concluded work on seven new ‘nanodevices’, which have been calibrated and tested for use in work environments exposed to nanoparticles. This work, alongside findings from materials studies and research into the association between ENM properties and their biological impacts, will appear in a new nanosafety handbook, called “Safe handling of manufactured nanomaterials: particle measurement exposure assessment and risk management”.

Complex research like this calls for an integrated, multidisciplinary approach,” confirms Nanodevice’s project leader, Dr Kai Savolainen of the Finnish Institute of Occupational Health.

What makes this particular health and safety project special is the focus on affordable monitoring for small and medium-size companies,

With affordable, portable equipment, even small companies can regularly measure their workers’ exposure to potentially harmful particles. When compared with a growing body of data from other workplaces, a more accurate assessment of risk and occupational health and safety emerges.

Prior to Nanodevice’s portable solutions, regular nanosafety checks could cost up to €200 000. The instrumentation hauled in from outside weighed hundreds of kilos and needed several experts to gather and analyse data from multiple sites. Big companies could afford this, but Europe’s important SME sector struggled with the cost.

“We’ve developed devices like a personal nanoparticle monitor for less than €200 that almost any company can afford and quickly learn to use,” says Dr Savolainen. Worn by a worker, the system collects exposure information, but needs to be plugged into a computer to download the data. This is not ideal, so Nanodevice is keen to develop this into a real-time sensing and monitoring device linked to the internet and databases.

“Today, lack of ‘big’ accurate data makes it hard to know if exposure values are too low,” explains Dr Savolainen, “so our work helps the scientific community build a large database on exposure levels in the working environment.” This means companies, regulators and stakeholders will have access to reliable information from which to base risk-assessment decisions and develop standards for occupational exposure levels for different types of ENMs.

“Thanks to our work, the ‘big picture’ is that people won’t have to be concerned about lack of information on exposure levels. This reduces uncertainty about ENM safety and fosters more innovation in nanosciences in general,” he concludes.

You can find out more about the Nanodevice project here.

Finally, the UK’s Health and Safety Executive released a guidance (I think we’d call them guidelines here in Canada) according to a Mar. 28, 2013 news item on Nanowerk (Note: A link has been removed),

The UK’s Health and Safety Executive (HSE) has released a new guidance (“Using nanomaterials at work”; pdf)that describes how to control occupational exposure to manufactured nanomaterials in the workplace. It will help you understand what you need to do to comply with the Control of Substances Hazardous to Health Regulations 2002 (COSHH) (as amended) when you work with these substances.

There’s more information about the guidance on the Using nanomaterials at work webpage where you can also find the document,

If you work with nanomaterials this guidance will help you protect your employees. If you run a medium-sized or large business, where decisions about controlling hazardous substances are more complex, you may also need professional advice. This guidance will also be useful for trade union and employee health and safety representatives.

This guidance is specifically about the manufacture and manipulation of all manufactured nanomaterials, carbon nanotubes (CNTs) and other bio-persistent high aspect ratio nanomaterials (HARNs). It has been prepared in response to emerging evidence about the toxicity of these materials.

The control principles described can be applied to all nanomaterials used in the workplace. Any differences in the approach between control of CNTs and other bio-persistent HARNs to any other type of nanomaterials are highlighted in the text.

For anyone who wants a direct link to the guidance, go here.

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Multi-walled carbon nanotubes, cancer, and the US National Institute of Occupational Health and Safety’s (NIOSH) latest findings

Tuesday, March 12th, 2013

A Mar. 11, 2013 news item on Nanowerk reveals some of the latest research performed by US National Institute of Occupational Health Safety (NIOSH) researchers into the question of whether or not multi-walled carbon nanotubes (MWCNT) cause cancer,

Earlier today, at the annual meeting of the Society of Toxicology, NIOSH researchers reported preliminary findings from a new laboratory study in which mice were exposed by inhalation to multi-walled carbon nanotubes (MWCNT). The study was designed to investigate whether these tiny particles have potential to initiate or promote cancer. By “initiate,” we mean the ability of a substance to cause mutations in DNA that can lead to tumors. By “promote,” we mean the ability of a substance to cause cells that have already sustained such DNA mutations to then become tumors.

It is very important to have new data that describe the potential health hazards that these materials might represent, so that protective measures can be developed to ensure the safe advancement of nanotechnology in the many industries where it is being applied.

The Mar. 11, 2013 posting (which originated the news item) by Vincent Castranova, PhD; Charles L Geraci, PhD; Paul Schulte, PhD  on the NIOSH blog provides details about the experimental protocols and the outcome of the experiments,

In the NIOSH study, a group of laboratory mice were injected with a chemical that is a known cancer initiator, methylcholanthrene.  Another group of mice were injected with a saline solution as a control group.  The mice then were exposed by inhalation either to air or to a concentration of MWCNT.   These protocols enabled the researchers to investigate whether MWNCT alone would initiate cancer in mice, or whether MWCNT would promote cancer where the initiator, methylcholanthrene, had already been applied.

Mice receiving both the initiator chemical plus exposure to MWCNT were significantly more likely to develop tumors (90% incidence) and have more tumors (an average of 3.3 tumors/mouse lung) than mice receiving the initiator chemical alone (50% of mice developing tumors with an average of 1.4 tumors/lung).  Additionally, mice exposed to MWCNT and to MWCNT plus the initiator chemical had larger tumors than the respective control groups.  The number of tumors per animal exposed to MWCNT alone was not significantly elevated compared with the number per animal in the controls.  These results indicate that MWCNT can increase the risk of cancer in mice exposed to a known carcinogen.  The study does not suggest that MWCNTs alone cause cancer in mice.

That last sentence is quite important because (from the NIOSH blog post),

Several earlier studies in the scientific literature indicated that MWCNT could have the potential to initiate or promote cancer. The new NIOSH study is the first to show that MWCNT is a cancer promoter in a laboratory experiment, and reports the growth of lung tumors in laboratory mice following inhalation exposure to MWCNT rather than injection, instillation, or aspiration.  Inhalation exposure most closely resembles the exposure route of greatest concern in the workplace. In the study, laboratory mice were exposed to one type of MWCNT through inhalation at a concentration of 5 milligrams per cubic meter of air for five hours per day for a period of 15 days.

Risk of occupational cancer depends on the potency of a given substance to cause or promote cancer and the concentration and duration of worker exposure to that substance.  This research is an important step in our understanding of the hazard associated with MWCNT, but before we can determine whether MWCNT pose an occupational cancer risk, we need more information about actual exposure levels and the types and nature of MWCNT being used in the workplace, and how that compares to the material  used in this study.

This study is part of a larger program designed to establish safety practices with regard to handling nanomaterials/nanoparticles (from the NIOSH blog post),

These laboratory studies are part of a strategic program of NIOSH research to better understand the occupational health and safety implications of nanoparticle exposure, and to make authoritative science-based recommendations for controlling exposures so that the technology is developed responsibly as the research advances, and the societal benefits of nanotechnology can be realized.  NIOSH has worked closely with diverse public and private sector partners over the past decade to incorporate occupational health and safety into practical strategies for safe development of this revolutionary technology. More information is available on the NIOSH nanotechnology topic page.

There is no mention in the blog post as to whether the MWCNTs in this latest work were long or short or a mixture of both. Unfortunately, the study has not yet been published in a journal, so it’s not yet available for reading purposes. I did mention carbon nanotubes and toxicity in a Jan. 16, 2013 posting about a recent study,

Researchers at the University College of London (UCL), France’s Centre national de la recherche scientifique (CNRS), and Italy’s University of Trieste have determined that carbon nanotube toxicity issues can be addressed be reducing their length and treating them chemically.

While I find this latest work from NIOSH interesting, it’s hard for me to understand why there’s no mention of length. Unless, the NIOSH work is focused on what happens when MWCNTs are inhaled along with known cancer initiators and they believe that length is not a factor.

ETA Mar. 15, 2013: I did find get some information about the length (long carbon nanotubes for the most part) as per this Mar. 14, 2013 posting or you can find the update in my Mar. 15, 2013 posting here.

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Clay disks and flowerpots that purify water

Monday, March 4th, 2013

Ben Schiller writes in a Mar. 1, 2013 article for Fast Company about a not-for-profit organization, PureMadi, a joint venture between the University of Virginia (US) and the University of Venda (South Africa) and its water purification technology,

PuriMadi has already built a factory in the Limpopo province of South Africa and hopes to expand further. “Eventually that factory will be capable of producing about 500 to 1,000 filters per month, and our 10-year plan is to build 10 to 12 factories in South Africa and other countries,” Smith says. “We plan to eventually serve at least 500,000 people per year with new filters.”

The University of Virginia Feb. 5, 2013 news release by Fariss Samarrai describes both a disc and a flowerpot version of the water purification technology (Note: Some links have been removed),

PureMadi, a nonprofit University of Virginia organization, will introduce a new invention – a simple ceramic water purification tablet – during its one-year celebration event Friday [Feb. 8, 2013] from 7 to 11 p.m. at Alumni Hall.

Called MadiDrop, the tablet – developed and extensively tested at U.Va. – is a small ceramic disk impregnated with silver or copper nanoparticles. It can repeatedly disinfect water for up to six months simply by resting in a vessel where water is poured. It is being developed for use in communities in South Africa that have little or no access to clean water.

“Madi” is the Tshivenda South African word for water. PureMadi brings together U.Va. professors and students to improve water quality, human health, local enterprise and quality of life in the developing world. The organization includes students and faculty members from engineering, architecture, medicine, nursing, business, commerce, economics, anthropology and foreign affairs.

During the past year, PureMadi has established a water filter factory in Limpopo province, South Africa, employing local workers. The factory produced several hundred flowerpot-like water filters, according to James Smith, a U.Va. civil and environmental engineer who co-leads the project with Dr. Rebecca Dillingham, director of U.Va.’s Center for Global Health.

Here’s the flowerpot filter,

A worker molds a filter from local clay, sawdust and water. (Photo: Rachel Schmidt)


A worker molds a filter from local clay, sawdust and water. (Photo: Rachel Schmidt)

Here are the discs or, as they are known, the MadiDrops,

The new MadiDrops can be produced in the same factories as the filters. (Photo: Rachel Schmidt)


The new MadiDrops can be produced in the same factories as the filters. (Photo: Rachel Schmidt)

The factory is more than just a producer of water purification technologies, from the University of Virgina news release,

“Eventually that factory will be capable of producing about 500 to 1,000 filters per month, and our 10-year plan is to build 10 to 12 factories in South Africa and other countries,” Smith said. “Each filter can serve a family of five or six for two to five years, so we plan to eventually serve at least 500,000 people per year with new filters.”

The idea is to create sustainable businesses that serve their communities and employ local workers. A small percentage of the profits go back to PureMadi and will be used to help establish more factories.

The PureMadi website’s About page offers more information about the partners, the technology, and the economic impact,

PureMadi has been created by an interdisciplinary collaboration of students and faculty at the University of Virginia.  In partnership with the University of Venda in Thohoyandou, South Africa, and developing-world communities in Limpopo Province, South Africa, PureMadi is working to provide sustainable solutions to global water problems.

Our first project is the development of a sustainable, ceramic water filter factory in South Africa.  Ceramic filters are a point-of-use (e.g. household-level) water treatment technology.  Ceramic filters can be produced with local materials (clay, sawdust, and water) and local labor. The materials are mixed in appropriate proportions, pressed into the shape of a filter pot, and fired in a kiln at 900 ˚C.  Upon firing, the clay forms a ceramic and the sawdust combusts, leaving a porous ceramic matrix for filtration.  In addition, the filters are treated with a dilute solution of silver nanoparticles.  The nanoparticles lodge in the pore space of the ceramic matrix and act as a highly effective disinfectant for waterborne pathogens like Vibrio cholerae and pathogenic strains of Escherichia coli.   Untreated water can then be passed through the filter and collected in a lower reservoir with a spigot to obtain purified water.

In the field and in the laboratory, we have demonstrated that this technology is highly effective at purifying water and the filters are socially acceptable to developing-world communities.  In some of our most recent work, we have shown that the filters significantly improve the health outcomes of human populations using the filters relative to groups who only drink untreated water.

A filter factory can become a sustainable business venture that provides economic stimulus to the local community.  Our goal is to create a blueprint for a successful factory, including its architecture, efficiency of water and energy use, technological performance of the filter itself, and an effective and sustainable business model.

While the flowerpot filter has been well received the MadiDrop fills another need, from the University of Virginia news release,

MadiDrop is an alternative to the flowerpot filter, but ideally would be used in conjunction with it. The plan is to mass-produce the product at the same factories where the PureMadi filters are produced.

“MadiDrop is cheaper, easier to use, and is easier to transport than the PureMadi filter, but because it is placed into the water, rather than having the water filter through it, the MadiDrop is not effective for removing sediment in water that causes discoloration or flavor impairment,” Smith said. “But its ease of use, cost-effectiveness and simple manufacturing process should allow us to make it readily available to a substantial population of users, more so than the more expensive PureMadi filter.”

Testing shows that the filters are safe to use and release only trace amounts of silver or copper particles, well within the safe water standards of the developed world. The filters also would be useful in rural areas of developed countries such as the United States where people rely on untreated well water.

Smith noted that U.Va. Architecture School professor Anselmo Canfora and his students have worked closely with PureMadi to design sustainable filter factories for developing countries that would optimize use of local labor and materials.

The National Science Foundation, the National Institutes of Health, U.Va.’s Jefferson Public Citizen Program and the Vice Provost for Global Affairs provide support to PureMadi. Partners include the University of Venda in South Africa; Potters for Peace, a nonprofit organization committed to providing safe drinking water in the developing world; and local communities in Limpopo province in South Africa.

Taken in conjunction with my Feb. 28, 2013 posting titled, Silver nanoparticles, water, the environment, and toxicity, where I juxtaposed two articles about toxicity and silver nanoparticles (they’re ok/they’re not ok) to illustrate the complexity surrounding the question of risk, this article which features silver (and copper) nanoparticles in use for water purification adds another dimension to the question. What are the risks?, to add, are they worth taking?

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Biosensing cocaine

Wednesday, February 13th, 2013

Amusingly, the Feb. 13, 2013 news item on Nanowerk highlights the biosensing aspect of the work in its title,

New biosensing nanotechnology adopts natural mechanisms to detect molecules

(Nanowerk News) Since the beginning of time, living organisms have developed ingenious mechanisms to monitor their environment.

The Feb. 13, 2013 news release from the University of Montreal (Université de Montréal) takes a somewhat different tack by focusing on cocaine,

Detecting cocaine “naturally”

Since the beginning of time, living organisms have developed ingenious mechanisms to monitor their environment. As part of an international study, a team of researchers has adapted some of these natural mechanisms to detect specific molecules such as cocaine more accurately and quickly. Their work may greatly facilitate the rapid screening—less than five minutes—of many drugs, infectious diseases, and cancers.

Professor Alexis Vallée-Bélisle of the University of Montreal Department of Chemistry has worked with Professor Francesco Ricci of the University of Rome Tor Vergata and Professor Kevin W. Plaxco of the University of California at Santa Barbara to improve a new biosensing nanotechnology. The results of the study were recently published in the Journal of American Chemical Society (JACS).

The scientists have provided an interesting image to illustrate their work,

Artist's rendering: the research team used an existing cocaine biosensor (in green) and revised its design to react to a series of inhibitor molecules (in blue). They were able to adapt the biosensor to respond optimally even within a large concentration window. Courtesy: University of Montreal

Artist’s rendering: the research team used an existing cocaine biosensor (in green) and revised its design to react to a series of inhibitor molecules (in blue). They were able to adapt the biosensor to respond optimally even within a large concentration window. Courtesy: University of Montreal

The news release provides some insight into the current state of biosensing and what the research team was attempting to accomplish,

“Nature is a continuing source of inspiration for developing new technologies,” says Professor Francesco Ricci, senior author of the study. “Many scientists are currently working to develop biosensor technology to detect—directly in the bloodstream and in seconds—drug, disease, and cancer molecules.”

“The most recent rapid and easy-to-use biosensors developed by scientists to determine the levels of various molecules such as drugs and disease markers in the blood only do so when the molecule is present in a certain concentration, called the concentration window,” adds Professor Vallée-Bélisle. “Below or above this window, current biosensors lose much of their accuracy.”

To overcome this limitation, the international team looked at nature: “In cells, living organisms often use inhibitor or activator molecules to automatically program the sensitivity of their receptors (sensors), which are able to identify the precise amount of thousand of molecules in seconds,” explains Professor Vallée-Bélisle. “We therefore decided to adapt these inhibition, activation, and sequestration mechanisms to improve the efficiency of artificial biosensors.”

The researchers put their idea to the test by using an existing cocaine biosensor and revising its design so that it would respond to a series of inhibitor molecules. They were able to adapt the biosensor to respond optimally even with a large concentration window. “What is fascinating,” says Alessandro Porchetta, a doctoral student at the University of Rome, “is that we were successful in controlling the interactions of this system by mimicking mechanisms that occur naturally.”

“Besides the obvious applications in biosensor design, I think this work will pave the way for important applications related to the administration of cancer-targeting drugs, an area of increasing importance,” says Professor Kevin Plaxco. “The ability to accurately regulate biosensor or nanomachine’s activities will greatly increase their efficiency.”

The funders for this project are (from the news release),

… the Italian Ministry of Universities and Research (MIUR), the Bill & Melinda Gates Foundation Grand Challenges Explorations program, the European Commission Marie Curie Actions program, the U.S. National Institutes of Health, and the Fonds de recherche du Québec Nature et Technologies.

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

Using Distal-Site Mutations and Allosteric Inhibition To Tune, Extend, and Narrow the Useful Dynamic Range of Aptamer-Based Sensors by Alessandro Porchetta, Alexis Vallée-Bélisle, Kevin W. Plaxco, and Francesco Ricci. J. Am. Chem. Soc., 2012, 134 (51), pp 20601–20604 DOI: 10.1021/ja310585e Publication Date (Web): December 6, 2012

Copyright © 2012 American Chemical Society

This article is behind a paywall.

One final note, Alexis Vallée-Bélisle has been mentioned here before in the context of a ‘Grand Challenges Canada programme’ (not the Bill and Melinda Gates ‘Grand Challenges’) announcement of several fundees  in my Nov. 22, 2012 posting. That funding appears to be for a difference project.

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The yin and the yang of carbon nanotubes and toxicity

Wednesday, January 16th, 2013

 

Illustration courtesy of the University College of London (UCL). Downloaded from http://www.ucl.ac.uk/news/news-articles/0113/130115-chemistry-resolves-toxic-concerns-about-carbon-nanotubes

Illustration courtesy of the University College of London (UCL). Downloaded from http://www.ucl.ac.uk/news/news-articles/0113/130115-chemistry-resolves-toxic-concerns-about-carbon-nanotubes

Researchers at the University College of London (UCL), France’s Centre national de la recherche scientifique (CNRS), and Italy’s University of Trieste have determined that carbon nanotube toxicity issues can be addressed be reducing their length and treating them chemically. From the Jan. 15,2013 news item on ScienceDaily,

In a new study, published January 15 [2013] in the journal Angewandte Chemie, evidence is provided that the asbestos-like reactivity and pathogenicity reported for long, pristine nanotubes can be completely alleviated if their surface is modified and their effective length is reduced as a result of chemical treatment.

First atomically described in the 1990s, carbon nanotubes are sheets of carbon atoms rolled up into hollow tubes just a few nanometres in diameter. Engineered carbon nanotubes can be chemically modified, with the addition of chemotherapeutic drugs, fluorescent tags or nucleic acids — opening up applications in cancer and gene therapy.

Furthermore, these chemically modified carbon nanotubes can pierce the cell membrane, acting as a kind of ‘nano-needle’, allowing the possibility of efficient transport of therapeutic and diagnostic agents directly into the cytoplasm of cells.

Among their downsides however, have been concerns about their safety profile. One of the most serious concerns, highlighted in 2008, involves the carcinogenic risk from the exposure and persistence of such fibres in the body. Some studies indicate that when long untreated carbon nanotubes are injected to the abdominal cavity of mice they can induce unwanted responses resembling those associated with exposure to certain asbestos fibres.

In this paper, the authors describe two different reactions which ask if any chemical modification can render the nanotubes non-toxic. They conclude that not all chemical treatments alleviate the toxicity risks associated with the material. Only those reactions that are able to render carbon nanotubes short and stably suspended in biological fluids without aggregation are able to result in safe, risk-free material.

Here’s a citation and link for this latest  research, from the ScienceDaily news item where you can also read the lead researcher’s comments about carbon nanotubes, safety, and unreasonable proposals to halt production,

Hanene Ali-Boucetta, Antonio Nunes, Raquel Sainz, M. Antonia Herrero, Bowen Tian, Maurizio Prato, Alberto Bianco, Kostas Kostarelos. Asbestos-like Pathogenicity of Long Carbon Nanotubes Alleviated by Chemical Functionalization. Angewandte Chemie International Edition, 2013; DOI: 10.1002/anie.201207664

The article is behind a paywall. I have mentioned long carbon nanotubes and their resemblance to asbestos fibres in several posts. The  Oct. 26, 2009 posting [scroll down about 1/3 of the way] highlights research which took place after the study where mice had carbon nanotubes injected into their bellies; in this second piece of research they inhaled the nanotubes.

ETA Jan. 21, 2013: Dexter Johnson gives context and commentary about this latest research into long multiwalled nanotubes (MWNTs) which he sums up as the answer to this question “What if you kept the MWNTs short?”  in a Jan. 18, 2013 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website)

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Posted in health and safety, nanotechnology | 3 Comments »

Nanotechnology, Innovation and Global Development Call for papers: special issue of International Journal of Technology and Globalisation

Monday, December 3rd, 2012

The Dec. 2, 2012 news item on Nanowerk provides details about an upcoming issue of the International Journal of Technology and Globalisation (Inderscience Publishers), which is focused on nanotechnology,

Advances in nanotechnology offer a wide range of opportunities for addressing global development challenges. Work is underway around the world to apply nanotechnology in a variety of sectors including agriculture, medicine, telecommunications, disaster management and environmental conservation.

A number of developing countries, especially in emerging markets, are starting to pay policy attention to this field. However, the majority of developing nations have not recognised the implications of nanotechnology for economic development.

The aim of this special issue of the International Journal of Technology and Globalisation is to provide a review of advances in nanotechnology or relevance to global development. Preference will be given to papers that combine assessment of emerging nanotechnologies and identification of policy options for action.  …

More information about the call can be found on the journal’s Nano special issue webpage,

Suitable topics include but are not limited to:

  • Nanotechnology, innovation and agriculture
  • Nanotechnology, innovation and pharmaceutical research
  • Nanotechnology, innovation and healthcare
  • Nanotechnology, innovation and water purification
  • Nanotechnology, innovation and industry
  • Nanotechnology, innovation and polymer research
  • Nanotechnology, innovation and computing
  • Nanotechnology and disaster management
  • Nanotechnology in environmental management
  • Nanotechnology research policy
  • Nanotechnology and technological leapfrogging
  • Nanotechnology and technological catch-up
  • Nanotechnology and innovation systems
  • Nanotechnology and international cooperation
  • Nanotechnology and science diplomacy
  • Nanotechnology and human health
  • Nanotechnology and the environment
  • Nanotechnology and regulation
  • Nanotechnology and public policy
  • Nanotechnology and governance
  • Nanotechnology and society
  • Status reviews of nanotechnology advances

Notes for Prospective Authors

Submitted papers should not have been previously published nor be currently under consideration for publication elsewhere. (N.B. Conference papers may only be submitted if the paper was not originally copyrighted and if it has been completely re-written).

All papers are refereed through a peer review process. A guide for authors, sample copies and other relevant information for submitting papers are available on the Author Guidelines page.

Important Dates

Manuscript submission: 15 June, 2013
Notification of initial decision: 15 July, 2013
Submission of revised manuscripts: 15 September, 2013
Notification of final acceptance: 15 October, 2013

…

Please do check the journal’s webpage for full details.

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Contraception and HIV protection in cloth*

Friday, November 30th, 2012

Researchers at the University of Washington have published a study in the peer-reviewed, open access journal, Public Library of Science ONE (PLoS ONE), concerning their work to produce fibres that can deliver both contraceptives and anti-HIV drugs, according to a Nov. 30, 2012 news item on Nanowerk,

The only way to protect against HIV and unintended pregnancy today is the condom. It’s an effective technology, but not appropriate or popular in all situations.

A University of Washington team has developed a versatile platform to simultaneously offer contraception and prevent HIV. Electrically spun cloth with nanometer-sized fibers can dissolve to release drugs, providing a platform for cheap, discrete and reversible protection.

Hannah Hickey’s  Nov. 30, 2012 University of Washington news release, which originated the news item, provides details,

“Our dream is to create a product women can use to protect themselves from HIV infection and unintended pregnancy,” said corresponding author Kim Woodrow, a UW assistant professor of bioengineering. “We have the drugs to do that. It’s really about delivering them in a way that makes them more potent, and allows a woman to want to use it.”

Electrospinning uses an electric field to catapult a charged fluid jet through air to create very fine, nanometer-scale fibers. The fibers can be manipulated to control the material’s solubility, strength and even geometry. Because of this versatility, fibers may be better at delivering medicine than existing technologies such as gels, tablets or pills. No high temperatures are involved, so the method is suitable for heat-sensitive molecules. The fabric can also incorporate large molecules, such as proteins and antibodies, that are hard to deliver through other methods.

…

They first dissolved polymers approved by the Food and Drug Administration and antiretroviral drugs used to treat HIV to create a gooey solution that passes through a syringe. As the stream encounters the electric field it stretches to create thin fibers measuring 100 to several thousand nanometers that whip through the air and eventually stick to a collecting plate (one nanometer is about one 25-millionth of an inch). The final material is a stretchy fabric that can physically block sperm or release chemical contraceptives and antivirals.

“This method allows controlled release of multiple compounds,” Ball said. “We were able to tune the fibers to have different release properties.”

One of the fabrics they made dissolves within minutes, potentially offering users immediate, discrete protection against unwanted pregnancy and sexually transmitted diseases.

Another dissolves gradually over a few days, providing an option for sustained delivery, more like the birth-control pill,  to provide contraception and guard against HIV.

The fabric could incorporate many fibers to guard against many different sexually transmitted infections, or include more than one anti-HIV drug to protect against drug-resistant strains (and discourage drug-resistant strains from emerging). Mixed fibers could be designed to release drugs at different times to increase their potency, like the prime-boost method used in vaccines.

The electrospun cloth could be inserted directly in the body or be used as a coating on vaginal rings or other products.

Electrospinning has existed for decades, but it’s only recently been automated to make it practical for applications such as filtration and tissue engineering. This is the first study to use nanofibers for vaginal drug delivery.

While this technology is more discrete than a condom, and potentially more versatile than pills or plastic or rubber devices, researchers say there is no single right answer.

The citation and link to the article,

Drug-Eluting Fibers for HIV-1 Inhibition and Contraception by Cameron Ball, Emily Krogstad, Thanyanan Chaowanachan, Kim A. Woodrow (2012) PLoS ONE 7(11): e49792. doi:10.1371/journal.pone.0049792

Last month, the Bill and Melinda Gates Foundation awarded these researchers a $1M grant to pursue this work.

*ETA Dec.2.12: I erroneously used the word clothing in the headline. It’s now been corrected to ‘cloth’.

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