Tag Archives: Nanowerk

Nanowerk announces new periodicals database

Leave a reply

If you are interested in searching out the various periodicals on nanotechnology and nanoscience, there’s a new, free database for you. From the Sept. 7, 2011 news item on Nanowerk,

Over the past few years, the number of these periodicals (not taking into account individual books, of course) has risen to over 230 titles – and counting. For instance, there are numerous planned journals for which ISSNs have been formally requested but that haven’t been published yet.

Taking this development into account, Nanowerk has expanded its series of free databases with a new Nanotechnology Periodicals directory, which can be found here on the Nanowerk site: http://www.nanowerk.com/nanotechnology/nanotechnology_periodicals.php

…

As of today, the Nanowerk Nanotechnology Periodicals directory has 237 entries that include 195 academic journals, 13 newsletters, 25 book series, and 4 popular or trade magazine formats from around the world. Of these, 55 titles are open access.

All of the listed titles appear to be English language publications (I checked some five or six pages of listings at random).

Using bacteria for bottom-up production of metal nanoparticles

Leave a reply

After admiring the descriptions for top-down and bottom-up nanoengineering in the report, Engineered Nanoparticles; Current Knowledge about OHS [Occupational Health and Safety] Risks and Prevention Measures, (my posting of Sept. 27, 2010), I came across Michael Berger’s very interesting article about bacteria and nanoparticle factories. From Bacteria as environmentally friendly nanoparticle factories on the Nanowerk site,

“The strategy of employing recombinant E. coli expressing metal binding proteins as a nanoparticle factory is generally applicable to the combinatorial synthesis of diverse nanoparticles having a wide range of characteristics, such as optical, electronic, chemical, and magnetic properties” Sang Yup Lee, head of the Metabolic & Biomolecular Engineering National Research Laboratory at KAIST, explains to Nanowerk. “Several physico-chemical processes that have been employed for the synthesis of metal nanoparticles involve processes at high temperatures in organic solvents, which are costly and environmentally unfriendly. Nanoparticles synthesized in recombinant E. coli cells are size-tunable at ambient temperature and possess chemical and optical characteristics comparable, if not identical, to those of chemically-synthesized nanoparticles.”

If you’d asked me a few years back about using bacteria to produce metallic nanoparticles, I would have been quite wary of the idea. However, these last few years of research and thinking have led me to a more relaxed if not altogether comfortable attitude toward this kind of nanobiotechnology. In fact, I find this particular project quite interesting and hopeful.

German report on nanosilver toxicity and some thoughts on the US EPA silver nanomaterials consultation

Leave a reply

More about nanosilver toxicology (see earlier posting about US EPA silver nanomaterials consultation) this week courtesy of an article by Michael Berger about a new report from a group of German researchers. From the article on Nanowerk,

Silver had already been recognized in ancient Greece and Rome for its infection-fighting properties but in modern times pharmaceutical companies made more money developing antibiotics. However, thanks to emerging nanotechnology applications, silver has made a comeback in the form of antimicrobial nanoparticle coatings for textiles, surgical instruments, lab equipment, floors or wall paints (see for instance: “Antibacterial nanotechnology multi-action materials that work day and night”).

The flip side of silver’s desired toxicity towards microbes is that it might have toxic effects for humans as well (“As nanotechnology goes mainstream, ‘toxic socks’ raise concerns”) and this has raised debate about the safety of nanosilver products. Although scientists have worked to reduce the toxicity of antimicrobial nanosilver in products, concerns remain.

Not helping to put these concerns to rest is a new report from a group of researchers in Germany that shows that toxicity of silver nanoparticles increases during storage because of slow dissolution under release of silver ions.

…

According to Epple [Matthias Epple, a professor for inorganic chemistry at the University of Duisburg-Essen], there is a general agreement that dissolved silver ions are responsible for the biological action that is especially pronounced against microorganisms. The lethal silver concentration of silver nanoparticles for human mesenchymal stem cells is about three times higher than that of silver ions (in terms of the absolute concentration of silver in a given solution).

The report has been published by the American Chemical Society in Chemistry of Materials. You can find an abstrect here, the full article is behind a paywall.

I was interested to note that the focus for the report is on the dissolution of nanoscale silver in water. By contrast, the US EPA consultation uses, as its starting point for the case study, nanoscale silver in an antibacterial spray. While laboratory researchers tend to focus on specifics such as the dissolution of  silver nanoparticles and ions, the EPA’s strategy allows for a 360o view. Theoretically, commenters could focus on anything from the production of the air spray, its own packaging, its use in various situations such as hospitals or food packaging, etc., and the various ways it dissipates into the environment, e.g. being washed off and ending up in the water supply.  This can lead to a comprehensive framework for future research activities examining more specific questions which provide answers that fit back into the framework.

Berger’s article reminds me of an October 29, 2009 news item on Science Daily about Swiss researchers, clothes washers, and nanosilver,

Scientists in Switzerland are reporting results of one of the first studies on the release of silver nanoparticles from laundering those anti-odor, anti-bacterial socks now on the market. Their findings may suggest ways that manufacturers and consumers can minimize the release of these particles to the environment, where they could harm fish and other wildlife.

…

They found that most of the released particles were relatively large and that most came out of the fabrics during the first wash. The total released varied from 1.3 to 35 percent of the total nanosilver in the fabric. Bleach generally did not affect the amount released. “These results have important implications for the risk assessment of silver textiles and also for environmental fate studies of nanosilver, because they show that under certain conditions relevant to washing, primarily coarse silver-containing particles are released,” the paper says.

The research report was published by the American Chemical Society’s Environmental Science and Technology journal. The abstract is available here, the full article is behind a paywall.

Intersection of philosophy, science policy, and nanotechnology regulation

Leave a reply

After coming across a mention of John Rawls in a July 11, 2010 posting by Richard Jones (Soft Machines blog) and his (Rawls’) notions about how people and groups with diverse interests can come to agreements on social norms, I wondered why I hadn’t heard of Rawls before and how his thinking might apply to nanotechnology regulatory frameworks.

Assuming I might not be alone in my ignorance of Rawls’ work, here’s a brief description from a Wikipedia essay,

John Bordley Rawls (February 21, 1921 – November 24, 2002) was an American philosopher and a leading figure in moral and political philosophy. … His magnum opus, A Theory of Justice (1971), is now regarded as “one of the primary texts in political philosophy.”[1] His work in political philosophy, dubbed Rawlsianism,[2] takes as its starting point the argument that “most reasonable principles of justice are those everyone would accept and agree to from a fair position.”[1]

(The footnote details can be found by following the essay link.) I think the idea of people being able to come to agreements when they operate from a fair position is both interesting and seems to be borne out by a recent study in the US that Steffen Foss Hansen has recently published in the Journal of Nanoparticle Research. Michael Berger at Nanowerk has written an in depth article about the study and multicriteria mapping, the technique used to measure and evaluate interviewees’ positions on nanotechnology regulatory frameworks. From the Berger article,

Multicriteria Mapping [MCM] is a computer-based decision analysis technique that provides a way of appraising a series of different potential ways forward on a complex and controversial policy problem. Like other multicriteria approaches, it involves developing a set of criteria, evaluating the performance of each option under each criterion, and weighting each criterion according to its relative importance.

Hansen interviewed 26 stakeholders, including academics, public civil servants, corporate lawyers, [public interest groups,] and representatives from worker unions, industrial companies, and trade association.

One aspect of this research that I thought particularly useful is that the interviews are structured dynamically. From the study,

Once the criteria had been defined, the interviewee was asked to evaluate the relative performance of the different policy options on a numerical scale (0–100) under each of the criteria one-by-one. Zero representing the worst relative performance and a 100 the best. In order to allow for uncertainty in the estimation MCM allows the interviewee to give a range (e.g., 20–30) and to make worst- and best-case assumptions. The lowest values assigned to an option would then reflect the option considered under worst case assumptions whereas the highest would reflect the same option considered under best-case assumptions. Throughout this scoring process the interviewee was asked to explain the value or range assigned to options and assumptions made. One interview had to be terminated at this stage of the interview as the participant realized that he/she had yet to develop a formalized opinion on the most preferred options. Others expressed some dislike with having to put a numerical estimate on something which they normally only discuss in qualitative terms. Others again found it challenging to have to look at all the options through all their criteria scoring and explaining the scoring of up to 72 combinations of policy options and criteria. Normally they would not have to explain their position in such depth.  …  MCM is an iterative process, so interviewees were free to return to review earlier steps of the process at any stage of the interview. (Journal of Nanoparticle Research, vol. 12, p. 1963)

Bravo to the interviewees for going through a demanding process and putting their opinions to the test. Also, I understood from reading the study that MCM captures both quantitative (as the preceding excerpt shows) and qualitative data, an approach I’ve always favoured.

Berger’s article goes on to discuss the results from the study,

“Adopting an incremental approach and implementing a new regulatory framework have been evaluated as the best options whereas a complete ban and no additional regulation of nanotechnology were the least favorable” Hansen explains the key findings to Nanowerk.

Participants described their idea of an ‘incremental approach’ as “…launching an incremental process using existing legislative structures—e.g., dangerous substances legislation, classification and labeling, cosmetic legislation, etc.—to the maximum, revisiting them, and, when appropriate only, amending them…” and a ‘new regulatory framework’ as “…launching a comprehensive, in-depth regulatory process specific to nanotechnologies that aims at developing an entirely new legislative framework that tries to take all the widely different nanomaterials and applications into consideration.”

Hansen notes that comparing the ranking of the various options by the stakeholder groups reveals that an incremental approach was ranked highest by a majority of the various stakeholder groups e.g. civil servants, public interest groups, industrial company representatives and corporate lawyers.

Who would have thought that the most extreme ends of opinion as represented by public interest groups that usually favour the precautionary principle and industrial company representatives who argue in favour of little or voluntary regulation could agree on an incremental approach? I suppose it gets back to Rawls and his notion of coming to an agreement from “a fair position.”

More work needs to be done, it’s a single study, only 26 interviews took place, the MCM is a snapshot of a moment in time and may no longer reflect the interviewee’s personal opinions, and the regulatory situation in the US has changed since these interviews took place. Still, with all these caveats, and I’m sure there are others, the study offers encouraging news about diverse groups being able to come to an agreement on the subject of nanotechnology regulatory frameworks.

Sunscreen and nanoparticles from ivy

1 Reply

I like a story about science research that starts with a question even if it does lead to another nanosunscreen posting this year (from a news item on Science Daily),

“What makes the ivy in [the] backyard cling to the fence so tightly?”

Associate professor of bioengineering at the University of Tennessee, Knoxville, Mingjun Zhang, asked himself that question one day while watching his son play in their back yard. Zhang’s answer may lead to the development of a new type of nanosunscreen, one that uses plant-based nanoparticles rather than metal-based ones.

Zhang speculated the greenery’s hidden power lay within a yellowish material secreted by the ivy for surface climbing. He placed this material onto a silicon wafer and examined it under an atomic force microscope and was surprised by what they found — lots of nanoparticles, tiny particles 1,000 times thinner than the diameter of a human hair. The properties of these tiny bits create the ability for the vine leaves to hold almost 2 million more times than its weight. It also has the ability to soak up and disperse light which is integral to sunscreens. [emphasis mine]

Michael Berger at Nanowerk has written an article (Harmless natural nanoparticles show potential to replace metal-based nanoparticles in sunscreen) discussing Dr. Zhang’s work in more depth,

Quite impressively, the team’s study indicates that ivy nanoparticles can improve the extinction of ultraviolet light at least four times better than its metal counterparts.

Zhang points out that sunscreens made with ivy nanoparticles may not need to be reapplied after swimming. “That’s because the plant’s nanoparticles are a bit more adhesive so sunscreens made with them may not wash off as easily as traditional sunscreens,” he says. “And while sunscreens made with metal-based nanoparticles give the skin a white tinge, sunscreens made with ivy nanoparticles are virtually invisible when applied to the skin.”

This certainly looks promising but they don’t seem to be anywhere near to producing sunscreens containing ivy nanoparticles.

A nanotechnology wrinkle

Leave a reply

A cosmetics ad (more about that in a minute) came back to memory this morning as I read Michael Berger’s Nanowerk Spotlight article (Using nanotechnology to unlock a fountain of bull) about a Thomson Reuters report on nanotechnology and the cosmetics industry. From the article,

Two days ago we ran a press release from Thomson Reuters about a brief report they compiled on patent data relating to nanotechnology in the cosmetics industry. …

It already begins with the sensational title: Can Nanotech Unlock The Fountain of Youth? (pdf). That certainly catches the eye of the layperson. What exactly face creams, shampoos and sunscreens have to do with the “fountain of youth” remains unexplained. Oh, and they do make a reference to ‘remote concepts’ like nanorobotics. So let your imagination run wild! Little NanoStretchinators (trademark pending Nanowerk) that remove wrinkles from underneath the skin maybe? Or the fully automated Follicle-NanoSeeder that restores the shining body of the male scalp?

After poking a little more fun at the report, Berger hones in on distortions such as this,

Not a word about potential risks, or health and environmental concerns. But when you look at these three quoted studies you get a different message. The initiative by the EPA they are referring to actually “will determine whether these materials present a potential environmental hazard or exposure over their life cycles, and how these materials, when used in products, may be modified or managed to avoid or mitigate potential human health or ecological impacts.”

Berger goes on to provide more eye opening references and comments. As for the ad I’d seen, it’s been a few months since I first saw it in one of my local daily newspapers but I clipped it since it featured this copy:

Euoko’s Eye Contour Nanolift
Like millions of very tiny plastic surgeons

Seems like a nanobot reference, doesn’t it?

It caught me eye because these days, it’s not often (almost never) that you see a cosmetics company overtly touting a nanotechnology product.  L’Oréal doesn’t mention ‘nanosomes’ after years of using the term in its marketing campaigns for its Revitalift ads (no nanosomes on the company’s Canadian website when I checked it this morning, July 15, 2010). If you’re interested in “millions of tiny plastic surgeons”, you can pay $320 CAD for 15 ml online here. Sadly, the website makes no mention of the plastic surgeons but there is this,

The cocktail for the post-injection, post-laser, post-surgery, post-peel era. Millions of lifting nanoparticles work with South American native rose moss and Asiatic pennywort to sustain instant and long-term surface smoothness. Lupine lipopeptides from France maximize optical properties of the skin to accentuate radiance. [emphasis mine]

On other wrinkling nanotechnology news, a news item on Nanowerk features this,

As a sign of aging or in a suit, wrinkles are almost never welcome, but two papers in the current issue of Physical Review Letters (“Smooth Cascade of Wrinkles at the Edge of a Floating Elastic Film” and “Draping Films: A Wrinkle to Fold Transition”) offer some perspective on what determines their size and shape in soft materials.

…

The experiments offer complimentary insights into how defects, such as an edge or a fold, influence the presence of wrinkles and could prove helpful in understanding the formation of wrinkles in biological tissue.

I’m curious as to funding details for this work being done by two different teams of physicists at the University of Massachusetts but I haven’t been able to track details. I was not able to access the research articles themselves and that’s usually where you can find those details.