Nanotechnology

[ramonmercado]

Another false dawn? There are some interesting pics etc at the links.

Researchers develop nano-sized 'cargo ships' to target and destroy tumors

http://www.physorg.com/printnews.php?newsid=140411034

The nanometer-sized cargo ships look individually like a chocolate-covered nut cluster, in which a biocompatible lipid forms the chocolate shell and magnetic nanoparticles, quantum dots and the drug doxorubicin are the nuts. Credit: Ji-Ho Park, UCSD
Click here to enlarge image


Scientists have developed nanometer-sized 'cargo ships' that can sail throughout the body via the bloodstream without immediate detection from the body's immune radar system and ferry their cargo of anti-cancer drugs and markers into tumors that might otherwise go untreated or undetected.


In a forthcoming issue of the Germany-based chemistry journal Angewandte Chemie, scientists at UC San Diego, UC Santa Barbara and MIT report that their nano-cargo-ship system integrates therapeutic and diagnostic functions into a single device that avoids rapid removal by the body's natural immune system.

"The idea involves encapsulating imaging agents and drugs into a protective 'mother ship' that evades the natural processes that normally would remove these payloads if they were unprotected," said Michael Sailor, a professor of chemistry and biochemistry at UCSD who headed the team of chemists, biologists and engineers that turned the fanciful concept into reality. "These mother ships are only 50 nanometers in diameter, or 1,000 times smaller than the diameter of a human hair, and are equipped with an array of molecules on their surfaces that enable them to find and penetrate tumor cells in the body."

These microscopic cargo ships could one day provide the means to more effectively deliver toxic anti-cancer drugs to tumors in high concentrations without negatively impacting other parts of the body.

"Many drugs look promising in the laboratory, but fail in humans because they do not reach the diseased tissue in time or at concentrations high enough to be effective," said Sangeeta Bhatia, a physician, bioengineer and professor of Health Sciences and Technology at MIT who played a key role in the development. "These drugs don't have the capability to avoid the body's natural defenses or to discriminate their intended targets from healthy tissues. In addition, we lack the tools to detect diseases such as cancer at the earliest stages of development, when therapies can be most effective."

The researchers designed the hull of the ships to evade detection by constructing them of specially modified lipids--a primary component of the surface of natural cells. The lipids were modified in such a way as to enable them to circulate in the bloodstream for many hours before being eliminated. This was demonstrated by the researchers in a series of experiments with mice.

The researchers also designed the material of the hull to be strong enough to prevent accidental release of its cargo while circulating through the bloodstream. Tethered to the surface of the hull is a protein called F3, a molecule that sticks to cancer cells. Prepared in the laboratory of Erkki Ruoslahti, a cell biologist and professor at the Burnham Institute for Medical Research at UC Santa Barbara, F3 was engineered to specifically home in on tumor cell surfaces and then transport itself into their nuclei.

"We are now constructing the next generation of smart tumor-targeting nanodevices," said Ruoslahti. "We hope that these devices will improve the diagnostic imaging of cancer and allow pinpoint targeting of treatments into cancerous tumors."

The researchers loaded their ships with three payloads before injecting them in the mice. Two types of nanoparticles, superparamagnetic iron oxide and fluorescent quantum dots, were placed in the ship's cargo hold, along with the anti-cancer drug doxorubicin. The iron oxide nanoparticles allow the ships to show up in a Magnetic Resonance Imaging, or MRI, scan, while the quantum dots can be seen with another type of imaging tool, a fluorescence scanner.

"The fluorescence image provides higher resolution than MRI," said Sailor. "One can imagine a surgeon identifying the specific location of a tumor in the body before surgery with an MRI scan, then using fluorescence imaging to find and remove all parts of the tumor during the operation."

The team found to its surprise in its experiments that a single mother-ship can carry multiple iron oxide nanoparticles, which increases their brightness in the MRI image.

"The ability of these nanostructures to carry more than one superparamagnetic nanoparticle makes them easier to see by MRI, which should translate to earlier detection of smaller tumors," said Sailor. "The fact that the ships can carry very dissimilar payloads—a magnetic nanoparticle, a fluorescent quantum dot, and a small molecule drug—was a real surprise."

The researchers noted that the construction of so-called "hybrid nanosystems" that contain multiple different types of nanoparticles is being explored by several other research groups. While hybrids have been used for various laboratory applications outside of living systems, said Sailor, there are limited studies done in vivo, or within live organisms, particularly for cancer imaging and therapy.

"That's because of the poor stability and short circulation times within the blood generally observed for these more complicated nanostructures," he added. As a result, the latest study is unique in one important way.

"This study provides the first example of a single nanomaterial used for simultaneous drug delivery and multimode imaging of diseased tissue in a live animal," said Ji-Ho Park, a graduate student in Sailor's laboratory who was part of the team. Geoffrey von Maltzahn, a graduate student working in Bhatia's laboratory, was also involved in the project, which was financed by a grant from the National Cancer Institute of the National Institutes of Health.

The nano mother ships look individually like a chocolate-covered nut cluster, in which a biocompatible lipid forms the chocolate shell and magnetic nanoparticles, quantum dots and the drug doxorubicin are the nuts. They sail through the bloodstream in groups that, under the electron microscope, look like small, broken strands of pearls.

The researchers are now working on developing ways to chemically treat the exteriors of the nano ships with specific chemical "zip codes," that will allow them to be delivered to specific tumors, organs and other sites in the body.

Film available at: http://luminance.ucsd.edu/video/nanoships.mov

The paper is now accessible in an early online version at: Draft

Source: University of California - San Diego

edit to fix link.

 

[ramonmercado]

The answer appears to be maybe.

Could Nanotechnology Solve The Water Crisis?
16 Sep 2008

Nanotechnology could be the answer to ensuring a safe supply of drinking water for regions of the world stricken by periodic drought or where water contamination is rife. Writing in the International Journal of Nuclear Desalination, researchers in India explain how carbon nanotubes could replace conventional materials in water-purification systems.

Water shortages and lack of access to safe drinking water will continue to grow as major global problems. At present, more than one billion people lack access to safe drinking water and 2.4 billion people lack access to proper sanitation, nearly all of them in the developing countries. At present a third of the world's population live in water-stressed countries, and by 2025, this is expected to rise to two-thirds.

S. Kar, R.C. Bindal, S. Prabhakar, P.K. Tewari, K. Dasgupta, and D. Sathiyamoorthy of the Bhabha Atomic Research Centre (BARC) in Mumbai, India, explain how new water purification technologies are constantly being investigated but to be viable in the developing world these have to be relatively simple and inexpensive to install, operate, and maintain.

They have turned to nanostructured, the carbon nanotubes, hollow carbon fibers less than a billionth the thickness of a human hair. The unique chemical properties of carbon nanotubes mean that only very small molecules, such as water molecules can pass along their interiors, whereas viruses, bacteria, toxic metal ions, and large noxious organic molecules cannot.

The team points out that the smooth and water repellant interior of carbon nanotubes means that a filter based on this technology would be very efficient, allowing a high flow rate of water through the filter without fouling. Importantly, the power needed to drive water through such a system will be low compared to conventional membrane technology.

However, to be useful as a nanotech filtration system for contaminated water, these nanoscale structures need to be engineered to form well-defined arrangements to allow the efficient decontamination of water. The team has now investigated the potential of forming water filtration systems based on carbon nanotubes that could remove arsenic, fluoride, heavy metals and toxic organic chemicals. Carbon nanotubes have impressive credentials for water purification, the researchers say.

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Article adapted by Medical News Today from original press release.
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Source: Soumitra Kar
Inderscience Publishers
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Article URL: http://www.medicalnewstoday.com/articles/121547.php

 

[ramonmercado]

More food for thought, not just scare speculation.

Nanomaterials May Have Large Environmental Footprint According To Yale Journal
25 Oct 2008

Environmental gains derived from the use of nanomaterials may be offset in part by the process used to manufacture them, according to research published in a special issue of the Journal of Industrial Ecology.

Hatice Şengül and colleagues at the University of Illinois at Chicago assert that strict material purity requirements, lower tolerances for defects and lower yields of manufacturing processes may lead to greater environmental burdens than those associated with conventional manufacturing. In a separate study of carbon nanofiber production, Vikas Khanna and colleagues at Ohio State University found, for example, that the life-cycle environmental impacts may be as much as 100 times greater per unit of weight than those of traditional materials, potentially offsetting some of the environmental benefits of the small size of nanomaterials.

Materials engineered at dimensions of 1 to 100 nanometers - (1 to100 billionths of a meter) - exhibit novel physical, chemical and biological characteristics, opening possibilities for stunning innovations in medicine, manufacturing and a host of other sectors of the economy. Because small quantities of nanomaterials can accomplish the tasks of much larger amounts of conventional materials, the expectation has been that nanomaterials will lower energy and resource use and the pollution that accompanies them. The possibility of constructing miniature devices atom-by-atom has also given rise to expectations that precision in nanomanufacturing will lead to less waste and cleaner processes.

"Research in this issue reveals the potential of environmental impacts from nanomanufacturing to offset the benefits of using lighter nanomaterials," says Gus Speth, dean of the Yale School of Forestry & Environmental Studies. "To date, most attention has focused on the possible toxic effects of exposure to nanoparticles - and appropriately so. But considerations of pollution and energy use arising from the production technologies used to make nanomaterials need attention as well."

Other topics explored in the special issue include:
Approaches for identifying and reducing the life cycle hazards of nanomaterials


Quantified life cycle energy requirements and environmental impacts from nanomaterials


Tradeoffs between nanomanufacturing costs and occupational exposure to nanoparticles


Efficiency of techniques for nanomaterials synthesis


Improvement of the sustainability of bio-based products through nanotechnology


Industrial frameworks for responsible nanotechnology


Industrial and public perception about the risks and benefits of nanomaterials


Governance and regulation of nanotechnology
Industrial ecology is a field that examines the opportunities for sustainable production and consumption, emphasizing the importance of a systems view of environmental threats and remedies. "Through the use of tools such as life cycle assessment, green chemistry and pollution prevention, industrial ecology takes a broad and deliberate view of environmental challenges," states Reid Lifset, editor-in-chief of the Journal of Industrial Ecology. "This special issue shows the power of this approach."

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Article adapted by Medical News Today from original press release.
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Roland Clift, professor of environmental technology in the Centre for Environmental Strategy at the University of Surrey, and Shannon Lloyd, principal research engineer in the Sustainability & Process Engineering Directorate at Concurrent Technologies Corporation, served as guest editors. Support for this special issue was provided by the Educational Foundation of America in Westport, Conn., and the Project on Emerging Nanotechnologies of the Woodrow Wilson International Center for Scholars in Washington, D.C.

The articles in this issue of Journal of Industrial Ecology are available online at http://www.interscience.wiley.com/journal/jie-nano. The Journal of Industrial Ecology is the official journal of the International Society for Industrial Ecology. It is published for Yale University on behalf of the Yale School of Forestry & Environmental Studies. For more information, visit http://www.interscience.wiley.com/journal/jie.

Source: David DeFusco
Yale University
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Article URL: http://www.medicalnewstoday.com/articles/126577.php

 

[ramonmercado]

Maybe nano-tech is the Beast of the Apocalypse.

For nano, religion in US dictates a wary view
http://www.physorg.com/printnews.php?newsid=147881829

When it comes to the world of the very, very small — nanotechnology — Americans have a big problem: Nano and its capacity to alter the fundamentals of nature, it seems, are failing the moral litmus test of religion.


In a report published today (Dec. 7) in the journal Nature Nanotechnology, survey results from the United States and Europe reveal a sharp contrast in the perception that nanotechnology is morally acceptable. Those views, according to the report, correlate directly with aggregate levels of religious views in each country surveyed.

In the United States and a few European countries where religion plays a larger role in everyday life, notably Italy, Austria and Ireland, nanotechnology and its potential to alter living organisms or even inspire synthetic life is perceived as less morally acceptable. In more secular European societies, such as those in France and Germany, individuals are much less likely to view nanotechnology through the prism of religion and find it ethically suspect.

"The level of 'religiosity' in a particular country is one of the strongest predictors of whether or not people see nanotechnology as morally acceptable," says Dietram Scheufele, a University of Wisconsin-Madison professor of life sciences communication and the lead author of the new study. "Religion was the strongest influence over everything."

The study compared answers to identical questions posed by the 2006 Eurobarometer public opinion survey and a 2007 poll by the University of Wisconsin Survey Center conducted under the auspices of the National Science Foundation-funded Center for Nanotechnology and Society at Arizona State University. The survey was led by Scheufele and Elizabeth Corley, an associate professor in the School of Public Affairs at Arizona State University.

The survey findings, says Scheufele, are important not only because they reveal the paradox of citizens of one of the world's elite technological societies taking a dim view of the implications of a particular technology, but also because they begin to expose broader negative public attitudes toward science when people filter their views through religion.

"What we captured is nanospecific, but it is also representative of a larger attitude toward science and technology," Scheufele says. "It raises a big question: What's really going on in our public discourse where science and religion often clash?"

For the United States, the findings are particularly surprising, Scheufele notes, as the country is without question a highly technological society and many of the discoveries that underpin nanotechnology emanated from American universities and companies. The technology is also becoming more pervasive, with more than 1,000 products ranging from more efficient solar panels and scratch-resistant automobile paint to souped-up golf clubs already on the market.

"It's estimated that nanotechnology will be a $3.1 trillion global industry by 2015," Scheufele says. "Nanotechnology is one of those areas that is starting to touch nearly every part of our lives."

To be sure that religion was such a dominant influence on perceptions of nanotechnology, the group controlled for such things as science literacy, educational performance, and levels of research productivity and funding directed to science and technology by different countries.

"We really tried to control for country-specific factors," Scheufele explains. "But we found that religion is still one of the strongest predictors of whether or not nanotechnology is morally acceptable and whether or not it is perceived to be useful for society."

The findings from the 2007 U.S. survey, adds Scheufele, also suggest that in the United States the public's knowledge of nanotechnology has been static since a similar 2004 survey. Scheufele points to a paucity of news media interest and the notion that people who already hold strong views on the technology are not necessarily seeking factual information about it.

"There is absolutely no change in what people know about nanotechnology between 2004 and 2007. This is partly due to the fact that mainstream media are only now beginning to pay closer attention to the issue. There has been a lot of elite discussion in Washington, D.C., but not a lot of public discussion. And nanotechnology has not had that catalytic moment, that key event that draws public attention to the issue."

Source: University of Wisconsin-Madison

 

[ramonmercado]

I wonder if Raquel Welch will be a crew member?

Medical "Mini-Submarine" To Blast Diseased Cells In The Body: A Fantastic Voyage Brought To Life
http://www.medicalnewstoday.com/articles/135726.php
16 Jan 2009

Ever since the 1966 Hollywood movie, doctors have imagined a real-life Fantastic Voyage a medical vehicle shrunk small enough to "submarine" in and fix faulty cells in the body. Thanks to new research by Tel Aviv University scientists, that reality may be only three years away.

The blueprints for the submarine and a map of its proposed maiden voyage were published earlier this year in Science by Dr. Dan Peer, who now leads the Tel Aviv University team at the Department of Cell Research and Immunology. The team will build and test-run the actual "machine" in human bodies. Dr. Peer originally developed the scenario at Harvard University.

Made from biological materials, the real-life medical submarine's Fantastic Voyage won't have enough room for Raquel Welch, but the nano-sized structure will be big enough to deliver the payload: effective drugs to kill cancer cells and eradicate faulty proteins.

A Nano-GPS System

"Our lab is creating biological nano-machines," says Dr. Peer. "These machines can target specific cells. In fact, we can target any protein that might be causing disease or disorder in the human body. This new invention treats the source, not the symptoms."

Dr. Peer's recent paper reported on the device's ability to target leukocytes (immune cells) in the guts of mice with ulcerative colitis. Calling his new invention a submarine, Dr. Peer has developed a nano-sized carrier which operates like a GPS system to locate and target cells. In the case of Crohn's disease, for example, it will target overactive immune system cells in the gut. In other diseases such as cancer, the submarine can aim for and deliver material to specific cancer cells, leaving the surrounding healthy cells intact.

While other researchers are working in the area of nano-medicine and drug delivery, Dr. Peer's submarines are among the first to combine a drug candidate with a drug delivery system. As the submarines float through the body, they latch onto the target cell and deliver their payload, a drug based on RNAi. This new kind of drug can affect faulty RNA machinery and reprogram cells to operate in normal ways. In essence, RNAi can essentially restore health to diseased cells or cause cells to die (like in the case of cancer cells).

Learning from the Body's Own System

Large pharmaceutical companies have already expressed interest in this research and in the area of RNAi in general. Currently, the Tel Aviv University lab is pairing its medical submarine with different RNAi compounds to target different pathologies, such as cancer, inflammation, and neurodegenerative diseases.

"We have tapped into the same ancient system the human body uses to protect itself from viruses," says Dr. Peer, who is also investigating a number of topical applications for his medical subs. "And the beauty of it is the basic material of our nano-carriers is natural," he says.

The Tel Aviv University team plans to launch their medical submarines, following FDA regulations, within three to five years. Their immediate focus is on blood, pancreatic, breast and brain cancers.

The researchers are currently collaborating with a number of teams around the world. In the area of breast cancer, they are working with researchers from Harvard University and MIT. In blood cancers, collaboration with the Dana-Farber Cancer Institute at Harvard Medical School is already progressing towards clinical trials.

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Article adapted by Medical News Today from original press release.
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Source: George Hunka
American Friends of Tel Aviv University
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[ramonmercado]

Ok, I reckopn this guy knows what he is talking about. No need to worry about pink goo.

Don Eigler: Two decades of nanotech
http://www.newscientist.com/article/mg2 ... otech.html
14 October 2009 by Duncan Graham-Rowe
Magazine issue 2729.

Manipulating atoms (Image: IBM)

The pioneer who wrote "IBM" using 35 xenon atoms in 1989 tells New Scientist how nanotech is progressing.

What made you spell out "IBM" in xenon atoms? Was it just a publicity stunt?

Our first experiments actually had nothing to do with atom manipulation, but what they taught us was that we could exert forces on atoms. Then we decided to see if we could reliably reposition them on a surface. Once we had managed to get the atom-moving process under control, the idea just came to me. The biggest challenge was remembering how to spell IBM.

What did this experiment mean for science?

It has proved to be an extremely powerful scientific tool, changing the way we think about building small structures and how we control things on a small scale. Prior to this it was only through chemistry that we were able to build atomically precise structures.

Did it have an impact on the rest of the world?

Twenty years ago hardly anybody used the word "nano". It was not part of our everyday jargon. Now I have an iPod Nano in my backpack.

Has nanotechnology trickled down into everyday life yet?

To some extent. It's showing up in coatings, cosmetics and sunscreens, and it's starting to show up in electronic devices. The length scales at which we manufacture computing devices are at the lower end of the nanometre scale. My laptop and cellphone are chock full of nanometre-scale technologies. But I think it's going to evolve to produce new technologies which will have a much broader impact.

What sort of evolution do you have in mind?

I like to differentiate between evolutionary technology and revolutionary technology. My cellphone and laptop contain evolutionary nanotechnology because they can be traced back to larger structures. Revolutionary is still very much in the future, but I'm thinking of things like new forms of drug delivery or new kinds of molecular structures. The bulk of the influence on the person in the street is still to come, but there's a 16-year-old kid out there now who's going to come up with something really wonderful.

What is your take on the health fears surrounding nanotechnology?

I have no concerns, but I do have great hopes. I think the beneficial effect of nanometre structures on health is likely to be revolutionary. But I'm also very much aware of the potential toxicological impacts of nanoparticles. My view on this, which is shared by most of my colleagues, is that with testing and an appropriate degree of regulation we'll be able to reap the benefits with very little in the way of a downside. That would be my hope - getting it right is our responsibility.

What are you currently working on?

We're trying to find new ways to do computation in very small structures, something that might be the follow on to the silicon transistor. Our focus is to see if we can do computation using only the spin degree of freedom of electrons.

Profile
Don Eigler is a physicist at IBM's Almaden Research Center in San Jose, California. He pioneered the use of scanning tunnelling microscopes to manipulate single atoms

 

[ramonmercado]

How long before the first nano-wire garotte?

Scientists bend nanowires into 2-D and 3-D structures
http://www.physorg.com/news175339313.html
October 21st, 2009 in Nanotechnology / Nanophysics


This is a false-color scanning electron microscope image of the zigzag nanowires in which the straight sections are separated by triangular joints and specific device functions are precisely localized at the kinked junctions in the nanowires. Credit: Bozhi Tian, Lieber Group, Harvard University


Taking nanomaterials to a new level of structural complexity, scientists have determined how to introduce kinks into arrow-straight nanowires, transforming them into zigzagging two- and three-dimensional structures with correspondingly advanced functions.

The work is described this week in the journal Nature Nanotechnology by Harvard University researchers led by Bozhi Tian and Charles M. Lieber.

Among other possible applications, the authors say, the new technology could foster a new nanoscale approach to detecting electrical currents in cells and tissues.

"We are very excited about the prospects this research opens up for nanotechnology," says Lieber, Mark Hyman, Jr. Professor of Chemistry in Harvard's Faculty of Arts and Sciences. "For example, our nanostructures make possible integration of active devices in nanoelectronic and photonic circuits, as well as totally new approaches for extra- and intracellular biological sensors. This latter area is one where we already have exciting new results, and one we believe can change the way much electrical recording in biology and medicine is carried out."

Lieber and Tian's approach involves the controlled introduction of triangular "stereocenters" -- essentially, fixed 120º joints -- into nanowires, structures that have previously been rigidly linear. These stereocenters, analogous to the chemical hubs found in many complex organic molecules, introduce kinks into 1-D nanostructures, transforming them into more complex forms.



Enlarge
This is a false-color scanning electron microscope image of the zigzag nanowires in which the straight sections are separated by triangular joints and specific device functions are precisely localized at the kinked junctions in the nanowires. Credit: Bozhi Tian, Lieber Group, Harvard University

The researchers were able to introduce stereocenters as nanowires self-assembled. They halted growth of the 1-D nanostructures for 15 seconds by removing key gaseous reactants from the chemical brew in which the process was taking place, replacing these reactants after joints had been introduced into the nanostructures. This approach resulted in a 40 percent yield of bent nanowires, which can then be purified to achieve higher yields.

"The stereocenters appear as 'kinks,' and the distance between kinks is completely controlled," says Tian, a research assistant in Harvard's Department of Chemistry and Chemical Biology. "Moreover, we demonstrated the generality of our approach through synthesis of 2-D silicon, germanium, and cadmium sulfide nanowire structures."

The research by Lieber and Tian is the latest in a years-long effort by scientists to control the composition and structure of nanowires during synthesis. Despite advances in these areas, the ability to control the design and growth of self-assembling nanostructures has been limited.

Lieber and Tian's work takes the formation of 2-D nanostructures a step further by enabling the introduction of electronic devices at the stereocenters.

"An important concept that emerged from these studies is that of introducing functionality at defined nanoscale points for the first time -- in other words, nanodevices that can 'self-label,'" Lieber says. "We illustrated this novel capability by the insertion of p-n diodes and field-effect transistors precisely at the stereocenters."

Such self-labeled structures could open up the possibility of introducing nanoelectronics, photodetectors, or biological sensors into complex nanoscale structures.

Source: Harvard University

 

[ramonmercado]

Ok, Doomsayer number 666. Back to worrying about the pink goo again.

Nanoparticles Can Damage DNA Without Crossing Cellular Barrier
http://www.popsci.com/science/article/2 ... t-exposure
Metal nanoparticles use a newly observed cell signal process to wreak havoc indirectly
By Jeremy Hsu Posted 11.06.2009 at 12:28 pm 0 Comments


DNA Damage Nanoparticles move in mysterious ways American Association for Cancer Research
Scientists know that nanoparticles can damage DNA in cells through direct interaction. Now, though, it appears that nanoparticles can also mess with DNA on the far side of a cellular barrier, by creating signaling molecules -- a never-before-seen phenomenon.

The finding could hint at unintended consequences: using nanoparticles to deliver medicine within the body, or for targeting specific cells such as cancerous clusters in tumors. But it also provides new insight into how small particles such as metal debris or viruses can influence the body, and might lead to new ways of delivering drug therapies.


Researchers behind the Nature Nanotechnology study told Physorg.com that their lab model does not resemble

the human body, and cautioned that cells receiving nanoparticle exposure might have greater separation in the body due to connective tissue and blood vessels.

For now, the BBC reports that the research team remains uncertain as to how exactly the signaling molecules triggered by the nanoparticles damaged DNA. But the realization that indirect exposure might matter as much as direct exposure suggests greater caution in deploying nanoparticles within the human body -- especially after the recent report of the first nanotech deaths from environmental exposure in China.

 

[Pietro_Mercurios]

Ok, Doomsayer number 666. Back to worrying about the pink goo again.

Nanoparticles Can Damage DNA Without Crossing Cellular Barrier
http://www.popsci.com/science/article/2 ... t-exposure
Metal nanoparticles use a newly observed cell signal process to wreak havoc indirectly
By Jeremy Hsu Posted 11.06.2009 at 12:28 pm 0 Comments


DNA Damage Nanoparticles move in mysterious ways American Association for Cancer Research
Scientists know that nanoparticles can damage DNA in cells through direct interaction. Now, though, it appears that nanoparticles can also mess with DNA on the far side of a cellular barrier, by creating signaling molecules -- a never-before-seen phenomenon.

The finding could hint at unintended consequences: using nanoparticles to deliver medicine within the body, or for targeting specific cells such as cancerous clusters in tumors. But it also provides new insight into how small particles such as metal debris or viruses can influence the body, and might lead to new ways of delivering drug therapies.


Researchers behind the Nature Nanotechnology study told Physorg.com that their lab model does not resemble

the human body, and cautioned that cells receiving nanoparticle exposure might have greater separation in the body due to connective tissue and blood vessels.

For now, the BBC reports that the research team remains uncertain as to how exactly the signaling molecules triggered by the nanoparticles damaged DNA. But the realization that indirect exposure might matter as much as direct exposure suggests greater caution in deploying nanoparticles within the human body -- especially after the recent report of the first nanotech deaths from environmental exposure in China.

Bio-Osmotic Nano-Catalytics = BONC for short

I'm afraid you've been rather badly BONC-ked Mr Smith.

Sounds a lot like Asbestosis, only more so.

 

[ramonmercado]

And its being criticised for being alarmist. Comments at link.

Experts Criticize Nanoparticle Study
http://sciencenow.sciencemag.org/cgi/co ... 009/1106/1
By Robert F. Service
ScienceNOW Daily News
6 November 2009

The headlines are laced with fear. "Nanoparticles 'can damage DNA.'" "Nanoparticle Safety Looking More Complicated." "Nanoparticles Indirect Threat to DNA." All seem to suggest that a new study, released yesterday, has found that nanoscale materials, used in everything from medical imaging to cancer treatment, can damage genetic material in our bodies, feeding public fears. But this particular study has little relevance to human exposure risks, experts say, and it is deeply flawed in other ways. "I think it's a meaningless study, to be blunt" says Günter Oberdörster, a nanotoxicologist at the University of Rochester in New York state.
Oberdörster and others agree that some concerns over nanoparticles are valid. These particles, 1 to 100 nanometers in size, are made from a wide variety and combination of elements. Their small size gives them unique optical, electrical, and chemical properties, raising concerns that they might have unforeseen effects in the body. And a variety of studies with animal models has shown that nanoparticles can trigger damage in living tissues (Science, 18 June 2004, p. 1732).

But the new work was narrower. Charles Patrick Case, an orthopedic specialist at the University of Bristol in the United Kingdom, and a raft of colleagues reported yesterday online in Nature Nanotechnology that cobalt-chromium particles--a smaller version of the metal alloy that is widely used in replacement joints--can damage distant cells in a specially-designed cell culture.

Case's team exposed a thin "barrier" of four layers of cancer cells to cobalt-chromium ions or particles. Cells close to the nanoparticles experienced signs of mitochondrial damage. But even cells on the other side of the barrier suffered some DNA damage, the team found, despite the fact that there was no evidence that the metals themselves moved through the cells to the other side of the barrier. Further studies suggested that damage to cells in the barrier triggered a chemical cascade that affected the neighboring cells, Case says.

In the paper, Case and colleagues suggest that, based on the results, nanoparticles used in a clinical setting might need to be evaluated for such unforeseen effects. "The potential damage to tissues located behind cell barriers needs to be considered when using nanoparticles for targeting disease states," the team writes. The point was further emphasized in a press release put out by Nature Nanotechnology this week: "These findings suggest that direct and indirect effects of nanoparticles on cells are equally crucial when considering the potential risks of their use in nanomedicine."

That's the kind of language that scares and confuses the public, says toxicologist Andre Nel of the University of California, Los Angeles. Especially, he and others say, when there's no evidence that the findings translate to people.

What's more, there are other reasons why the study isn't applicable to human health, says Andrew Maynard, chief scientist for the Woodrow Wilson International Center for Scholars' Project on Emerging Nanotechnologies in Washington, D.C. For starters, Maynard and others point out that Case's team exposed cells to metal particles at a concentration thousands of times higher than could be expected to occur in the body. "They forget completely that it's the dose that makes a poison and a mechanism of action," Oberdörster says. Even though the group found that micron-sized metal particles and metal ions also damage DNA, they focused primarily on nanoparticles. "The effects don't seem to be nanoparticle specific," Maynard points out.

In a press conference called to discuss the paper's results yesterday, Case said his team didn't set out to draw conclusions about the effects the metals may have in the body. Rather, he said, the study was designed to ask the more fundamental question of whether a physical barrier of cells would indeed act as a barrier to prevent damage to cells on the other side.

Such careful interpretations are often lost in news coverage and efforts by journals to promote coverage of particular papers, however. Nature Nanotechnology not only highlighted the paper in a news release but also organized the press conference, drawing additional attention to the study. "The danger is they created the controversy by giving it this attention," Maynard says. Nel points out that this is a regular occurrence in the nanotechnology area because the field is hot and it plays into peoples' fears about new technology. "We need to be much more careful in interpreting these results," Oberdörster says.

 

[ramonmercado]

Published online 28 September 2011 | Nature |
doi:10.1038/news.2011.562

Draft guidelines for nanomedicine unveiled
http://www.nature.com/news/2011/110928/ ... 1.562.html
With hundreds of nanoproducts currently being tested in humans, recommendations aim to safeguard trial participants.

Jessica Marshall


Nanoparticles are already being used to deliver drugs in the body.MEDI-MATION/SCIENCE PHOTO LIBRARY
Nanomedicines, advocates say, will one day be commonplace. Nanoparticles are already being used in bone-replacement composites and chemotherapy delivery systems, and more sophisticated systems could eventually carry personalized therapies to the precise site in the body where they are needed.

But their size — measured in billionths of a metre, on the same scale as much of our cellular machinery — means that nanoparticles could also have unexpected effects, such as triggering unwanted immune responses. Despite this, clinical trials of nanomedicines in humans have so far not been subject to specialized oversight.

That could be about to change. This week, two years into a project funded by the US National Institutes of Health, a research team has proposed what it calls the first comprehensive recommendations for the oversight of nanomedicine.

The team discussed a draft of its guidelines with an invited panel of experts, including senior government regulators and policymakers, in a meeting at the University of Minnesota in Minneapolis on 26 September. The panel's feedback led to some key conclusions, says the team's leader Susan Wolf, a law and bioethics expert at the University of Minnesota, who expects the final recommendations to guide future policy in the area.

Government guidelines

The team suggests creating two new bodies within the US Department of Health and Human Services. The first would be an interagency working group, including representatives from five government branches with a stake in nanomedicine. The group would be tasked with providing a checklist of key questions for agencies that have to evaluate the risks and hazards of nanoscale technologies. "The guts of it is to get the people with the right information talking to each other," says Wolf. "You really need a science-informed process for answering these questions and making sophisticated ethical judgements."

The second body would be an advisory committee that includes expert members of the public, akin to bodies that already exist for research on human subjects.

The team also decided that clinical-trial participants should, for now, be told explicitly whether their treatments involve nanoscale products. But it stopped short of recommending a protocol-by-protocol approval process, something that the Recombinant DNA Advisory Committee implements for human gene transfer research. "There's not the heightened hazard or risk for [nanomedicine] that would warrant that," says Wolf.

Holistic impact

Some bioethicists question how much separate oversight is needed for nanomedicine. Clinical trials that involve new molecular entities occur all the time, says R. Alta Charo, a bioethicist at the University of Wisconsin Law School in Madison and a former policy adviser to the US Food and Drug Administration. "The topics that we're looking at — how do you protect human subjects generally, how do you inform them before they volunteer, how do you estimate the risks — are absolutely standard, traditional issues," she adds.

But nanotherapies could also affect family members of people who receive them, people who manufacture the treatments, and health workers who deliver them. They might also have environmental implications if they make it through sewage treatment facilities into waterways.

"The one thing that does strike me as being genuinely different in the discussion here is the focus on occupational health and environmental issues as an aspect of the risk assessment," Charo told the conference in Minneapolis. "That is something we don't usually do in human-subjects research."

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Roughly 250 nanomedicine products are already being tested in humans, or are about to be. Mihail Roco, senior adviser for nanotechnology at the National Science Foundation in Washington DC, predicts that nanotechnology products will be in significant mass production by 2020, with about one-third of patents and start-up companies in the sector having biomedical applications.

As nanomedicine advances from passive technologies, in which nanoparticles act as vehicles for drugs, to active treatments that involve more complex cellular interactions, specialized oversight may become ever more necessary, says Roco. "This project is an example of anticipatory governance for nanotechnology that we've tried to promote for some time," he says.

Wolf and her colleagues aim to publish finalized recommendations by the end of the year.

 

[ramonmercado]

Nanoparticle hollowing method promises medical advances

http://www.bbc.co.uk/news/technology-16101495

By Leo Kelion Technology reporter


Electron transmission microscopy images show the nanoboxes with different interior structures

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A process to "carve" highly complicated shapes into nanoparticles has been unveiled by a team of researchers.

It involves a chemical process which hollows out the particles into shapes such as double-walled boxes and multi-chambered tubes.

The researchers said this would aid the creation of more complex nano-objects.

They said these could ultimately be used to revolutionise medical tests and aid drugs treatments.

Ion attack

The research was carried out by the Catalan Institute of Nanotechnology in Bellaterra, Spain and is published in the latest issue of Science.

To deliver their results the scientists refined a series of existing corrosion techniques including the "galvanic effect".

This involved treating tiny silver cubes with cationic gold - a type of gold that had had some electrons removed from its atoms, turning it into an ion.

When brought together at room temperature the cationic gold "attacked" the silver, stealing its electrons.

The loss of the electrons turned the affected silver atoms into ions which dissolved into a provided solution.

Meanwhile, by gaining electrons the cationic gold was transformed into "normal" metallic gold which was then deposited onto the top of the silver cube.

"This protects the silver - and as the cube's surface becomes covered, the reaction becomes more aggressive in other parts of the cube that have not been coated," said Prof Victor Puntes, the team's principal researcher.

"In the end you end up with a single hole on the surface of the silver which is not covered by gold where the reaction advances and then enters the cube from inside."

The professor said this prompted a second process known as the Kirkendall effect where silver atoms from inside the cube started "migrating" to the gold outside "offering themselves up" thus creating a void inside the cube.

"We can control the process to make different holes resulting in different structures," Prof Puntes added.

Although both the galvanic effect and the Kirkendall have been used for years, the scientists said that previous efforts to combine them in this way had failed because the galvanic effect was too aggressive.

They said their innovation was to introduce a range of factors which made the silver more resistant, the cationic gold less aggressive and dissolved by-products of the process which would have otherwise interfered with the structure's development.


The technique allows a range of hollowed shapes to be created in metallic nanoparticles Nano-device drugs

Although the process has only just been outlined, the scientists are excited by its potential uses for the medical industry.

They said particles could be hollowed out so that they absorbed different energy wavelengths, helping to create body scanners that would be more accurate than current magnetic resonance imaging (MRI) equipment.

The researchers added that the technique could also aid drug delivery.

"It's a wonderful molecular suitcase," said Prof Puntes.

"You can have different sizes of cavity meaning that different-sized molecules enter different rooms of a structure. So you can have complex and controlled relief on the nanoscale - like cell dosing - dosing with a mixture of drugs that would otherwise be difficult to carry out."

Other examples given included the creation of components for nanoscale robots and new techniques to remove pollution from the environment.

However, the professor acknowledged that at this early stage he could only guess at the eventual uses such nanomaterials would have.

"When people first invented plastic they didn't know what to do with it, we knew electricity was around for over a thousand years before we learned how to do something useful with it," Prof Puntes said.

"This creates different materials so they will probably have lots of different properties."

 

[ramonmercado]

Opinion: No Objections to Nano?
http://the-scientist.com/2012/02/03/opi ... s-to-nano/
While biotechnology has met with mixed public reactions, to date nanotechnology seems to invoke much less public concern.
By Susanna Priest | February 3, 2012
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Metal oxide nano particles
FLICKR, BASF - THE CHEMICAL COMPANY
Some forms of biotechnology have become notoriously controversial. Genetic modification of crops, for example, altered the food supply in ways some consumers found troublesome, either because of anticipated consequences, a lack of tangible benefit, lack of opportunity to participate in the decision-making, or simply a sense of inherent “unnaturalness.” Stem cell research has raised similar uneasiness, albeit for entirely different reasons, largely moral beliefs that equate it with the destruction of human embryos. So far, though, public perception of nanotechnology does not seem to be headed in the same direction. Sure, there are appeals for regulation and isolated protests, but it doesn’t seem as though there is really as much in the way of concerted will behind them. While some might be waiting for the other shoe to drop—I’ve been told many times that public concerns about nano are bound to emerge “just as soon as people understand what this is all about”—events so far suggest it may be a long wait.

Despite emerging evidence of potential toxicity to human health and the environment from some forms of nanotechnology under some circumstances, not much popular alarm has arisen. Great uncertainty remains over which products and under what circumstances we should be concerned, but of course this hasn’t stopped public reaction in the past. Several potential “triggering events” of the sort we social scientists might have expected would unleash underlying fears have already happened. In 2006, reports emerged of serious respiratory problems among German consumers using a household cleaning product called “Magic Nano,” and evidence published in 2009 indicated severe lung disease and even deaths among a small group of Chinese factory workers exposed to nanoparticles (and many other chemicals, as it turns out). In both cases, the link between nanotechnology and disease is far from clear. “Magic Nano” may not even have contained nanoparticles; the label was apparently chosen in an attempt to hype the product, much like the name “iPod nano.” Clearly, the marketers involved believed the word “nano” is attractive to consumers, rather than a source of concern for them.

To me, as a social scientist who studies risk communication, perception and reality are indeed the same thing, and so the interesting question is why, when uncertainty about risks has certainly not stopped public opinion from turning sour in the past, should nano be getting the benefit of the doubt while so much of bio remains persistently controversial?

The answer may lie in the nature of our technoscientific culture. I recently published a multi-year panel study involving 76 citizens of South Carolina, representing various walks of life, which reinforced the notion that because most Americans like technology, they are generally willing to give nanotechnology a pass, at least for now, even though they don’t know much about it. About two-thirds of the panel held positive views, and the negative minority seemed to draw on negative expectations about technology more generally, rather than specific views about nanotechnology. Panelists’ views changed little over the 32 months of the study. The most common concerns, reasonably enough, centered on unexpected consequences and unanticipated side effects. Indeed, people seemed perfectly aware of the uncertainties surrounding nano-associated risks, but this hardly appeared to induce fear.

To those of us who lived through the early years of the genetically modified (GM) food “wars,” which some tended to attribute to a lack of familiarity alongside low levels of trust, this is pretty interesting. Nano involves many of the same sorts of key actors (major corporations, government regulators, scientists, engineers, and consumer advocacy groups) and, if anything, even greater levels of scientific uncertainty. Yet there’s something quite different about what we call the “climate of public opinion” for nanotechnology as opposed to biotechnology, particularly GM. To be sure, some observers are invoking the so-called precautionary principle (the largely European idea that we should not adopt a technology until the evidence shows it does not cause harm), but even in such cases it usually seems that they are calling for precaution because they think this is generally the right way to manage any new technology, rather than because nanotechnology is particularly worrisome.

So what makes nano so different from bio? Simply put, manipulating DNA simply seems to challenge our underlying cultural ideas about how the world ought to be in ways that manipulating otherwise ordinary materials does not.

For those who want to communicate about risk in a responsible way with the so-called “lay” or non-specialist public, nano represents a novel challenge. Rather than being an “amplified” risk, by which I mean one that the media and other social institutions have tended to highlight, nanotechnology may represent an “attenuated” risk, or one that these institutions have tended to ignore. If people are too fearful of a technology, they may lose out on its potential benefits, yet if too trusting, they may ignore important risks. But few among us really want to be the one yelling “Fire!” in a crowded world. After all, we’re still not even sure there’s a problem. Are we?

Indeed, just last month (January 25), the National Research Council issued a report calling for a coordinated research plan to investigate nanotechnology’s poorly understood risks to both health and environment, lest its beneficial promise for society ultimately go unrealized.

Susanna Priest ([email protected]) is the author of Nanotechnology and the Public: Risk Perception and Risk Communication (Taylor and Francis, 2012), as well as a November 2011 article in Risk Analysis (Volume 31, Issue 11, pp. 1718-1733) on “Envisioning Emerging Technologies,” which reports on the panel study results as part of a special issue. She also edits the academic journal Science Communication.

 

[krakenten]

Nanotechnology will either save us, or destroy us. Or replace us. Or turn out to be a flash in the pan.

Or all of the above.

 

[ramonmercado]

I reckon this belongs here rather than in the Robot Roundup.

DNA Nanorobot Triggers Targeted Therapeutic Responses
http://www.sciencedaily.com/releases/20 ... 144238.htm

The programmable DNA nanorobot was modeled on the body's own immune system in which white blood cells patrol the bloodstream for any signs of trouble. (Credit: Image courtesy of Wyss Institute for Biologically Inspired Engineering at Harvard)

ScienceDaily (Feb. 16, 2012) — Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University have developed a robotic device made from DNA that could potentially seek out specific cell targets within a complex mixture of cell types and deliver important molecular instructions, such as telling cancer cells to self-destruct. Inspired by the mechanics of the body's own immune system, the technology might one day be used to program immune responses to treat various diseases.

The research findings recently appear in the journal Science.

Using the DNA origami method, in which complex three-dimensional shapes and objects are constructed by folding strands of DNA, Shawn Douglas, Ph.D., a Wyss Technology Development Fellow, and Ido Bachelet, Ph.D., a former Wyss Postdoctoral Fellow who is now an Assistant Professor in the Faculty of Life Sciences and the Nano-Center at Bar-Ilan University in Israel, created a nanosized robot in the form of an open barrel whose two halves are connected by a hinge. The DNA barrel, which acts as a container, is held shut by special DNA latches that can recognize and seek out combinations of cell-surface proteins, including disease markers. When the latches find their targets, they reconfigure, causing the two halves of the barrel to swing open and expose its contents, or payload. The container can hold various types of payloads, including specific molecules with encoded instructions that can interact with specific cell surface signaling receptors.

Douglas and Bachelet used this system to deliver instructions, which were encoded in antibody fragments, to two different types of cancer cells -- leukemia and lymphoma. In each case, the message to the cell was to activate its "suicide switch" -- a standard feature that allows aging or abnormal cells to be eliminated. And since leukemia and lymphoma cells speak different languages, the messages were written in different antibody combinations.

This programmable nanotherapeutic approach was modeled on the body's own immune system in which white blood cells patrol the bloodstream for any signs of trouble. These infection fighters are able to home in on specific cells in distress, bind to them, and transmit comprehensible signals to them to self-destruct. The DNA nanorobot emulates this level of specificity through the use of modular components in which different hinges and molecular messages can be switched in and out of the underlying delivery system, much as different engines and tires can be placed on the same chassis. The programmable power of this type of modularity means the system has the potential to one day be used to treat a variety of diseases.

"We can finally integrate sensing and logical computing functions via complex, yet predictable, nanostructures -- some of the first hybrids of structural DNA, antibodies, aptamers and metal atomic clusters -- aimed at useful, very specific targeting of human cancers and T-cells," said George Church, Ph.D., a Wyss core faculty member and Professor of Genetics at Harvard Medical School, who is Principal Investigator on the project. Because DNA is a natural biocompatible and biodegradable material, DNA nanotechnology is widely recognized for its potential as a delivery mechanism for drugs and molecular signals. But there have been significant challenges to its implementation, such as what type of structure to create; how to open, close, and reopen that structure to insert, transport, and deliver a payload; and how to program this type of nanoscale robot.

By combining several novel elements for the first time, the new system represents a significant advance in overcoming these implementation obstacles. For instance, because the barrel-shaped structure has no top or bottom lids, the payloads can be loaded from the side in a single step--without having to open the structure first and then reclose it. Also, while other systems use release mechanisms that respond to DNA or RNA, the novel mechanism used here responds to proteins, which are more commonly found on cell surfaces and are largely responsible for transmembrane signaling in cells. Finally, this is the first DNA-origami-based system that uses antibody fragments to convey molecular messages -- a feature that offers a controlled and programmable way to replicate an immune response or develop new types of targeted therapies.

"This work represents a major breakthrough in the field of nanobiotechnology as it demonstrates the ability to leverage recent advances in the field of DNA origami pioneered by researchers around the world, including the Wyss Institute's own William Shih, to meet a real-world challenge, namely killing cancer cells with high specificity," said Wyss Institute Founding Director, Donald Ingber, M.D., Ph.D. Ingber is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and the Vascular Biology Program at Children's Hospital Boston, and Professor of Bioengineering at Harvard's School of Engineering and Applied Sciences. "This focus on translating technologies from the laboratory into transformative products and therapies is what the Wyss Institute is all about."


Story Source:

The above story is reprinted from materials provided by Wyss Institute for Biologically Inspired Engineering at Harvard.

 

[ramonmercado]

You'll hear the pitter patter of nano feet.

Next Generation: World’s First Nano-ear
http://the-scientist.com/2012/02/10/nex ... -nano-ear/
A new device can detect sounds a million times fainter than the hearing threshold of the human ear.
By Megan Scudellari | February 10, 2012
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A newly developed method might be able to detect sound waves produced by bacteria and other nano? and micro-objects
NANOSYSTEMS INITIATIVE MUNICH
THE DEVICE: If a bacterium belches in a petri dish, does anyone hear it? In the January issue of Physical Review Letters, researchers at LMU Munich in Germany describe the world’s tiniest ear—an apparatus for the ultrasensitive detection of sound. By tracking the displacement of a levitating gold particle trapped in a focused laser beam, the team recorded the acoustic vibrations of nearby nanoparticles. The researchers were also able to determine from which direction the sound came.

The researchers estimate the nano-ear can detect sound levels as low as -60 decibels, making the device a million times more sensitive than human hearing.


The 'nano-ear'
COURTESY: AMERICAN PHYSICAL SOCIETY

WHAT’S NEW: Optical tweezers—infrared lasers focused through an optical microscope to trap tiny objects—are a standard tool used to study cells, metal particles, DNA, and more. Researchers can move the laser beam to pick up and manipulate these objects, studying their motion. But the LMU Munich team put the technique to a different use.

“We were wondering what happens if something disturbs this motion, for instance a sound wave,” said first author Alexander Ohlinger. “If it’s possible to detect that disturbance, we could use [the optical tweezers] as a microphone.”

Ohlinger and colleagues tested their theory in two experiments. First, they recorded the trapped particle’s response to a relatively strong sound source—a needle vibrating on a loudspeaker. Next, they detected the significantly weaker acoustics of a patch of vibrating gold nanoparticles, being heated up by a laser (see image above). In both instances, the acoustic waves were detected accurately.

IMPORTANCE: The nano-ear could open up a whole new field of “acoustic microscopy,” said Ohlinger. Using optical tweezers, scientists might be able to listen in on bacteria, viruses, and even cellular processes like DNA replication and mitosis.

The technique is highly accessible, as all the tools that were used—lasers, nanoparticles, a dark-field microscope, and an ordinary video camera to record the movement—can be readily acquired by a lab, Ohlinger added.

NEEDS IMPROVEMENT: Before the technique can be applied to biological systems, however, work must be done to reduce the signal to noise ratio, said Lene Oddershede, head of the optical tweezers group at the University of Copenhagen, who was not involved in the study. “When you’re at the nanoscale, noise is a really big player. It’s everywhere,” she said. With the noise-to-signal ratio reported in the paper, these extraneous noises could affect the intended measurements. “However, I do believe the signal-to-noise ratio can be improved,” Oddershede said.

The LMU Munich team is now performing studies applying the nano-ear to different systems, said Ohlinger. They would like to record the sound of micro-sized objects like cells, but first have to determine if the technique can record sound waves that are not periodic, as in their experiments, but random and messy. “We have to refine our method, but in principle, we hope that it’s possible to use in biology,” said Ohlinger. “This is all research in progress.”

A. Ohlinger, et al., “Optically Trapped Gold Nanoparticle Enables Listening at the Microscale,” Phys Rev Lett., 108, 018101, 2012.

 

[ramonmercado]

World's most sensitive scales detect a yoctogram
http://www.newscientist.com/article/dn2 ... ogram.html

18:00 01 April 2012 by Jessica Hamzelou

How do you weigh an atom down to the last proton? With scales accurate enough to measure the smallest unit of mass, aka the yoctogram, which is just one septillionth of a gram.

No ordinary scales will do ? the tiniest weights are measured using nanotubes, which vibrate at different frequencies depending on the mass of the particles or molecules on them. Until now, 100 yoctograms ? or a tenth of a zeptogram ? was the smallest mass the most sensitive sensor could detect.

To go even lower, Adrian Bachtold and his colleagues at the Catalan Institute of Nanotechnology in Barcelona, Spain, used short nanotubes. They give the best resolution and work at the low temperatures thought best for measuring frequency. Although the equipment was placed in a vacuum to minimise interference from other atoms, Bachtold removed any stray atoms by temporarily turning up the heat on the tubes to disrupt any bonds to atoms.

Then the sensor was able to weigh an atom of xenon to the nearest yoctogram, or 10-24 grams. This makes it the first scale capable of detecting a single proton, which weighs in at 1.7 yoctograms.

"The yoctogram mass sensitivity achieved by the Catalan team is certainly spectacular ? the challenge ahead will be to routinely manufacture nanotube sensors at low cost," says Rachel McKendry, a nanoscientist at University College London.

Bachtold hopes the scales could be used to distinguish different elements in chemical samples, which might differ only by a few protons. They might also diagnose health conditions by identifying proton-scale differences in molecular mass that are markers of disease.

Journal reference: Nature Nanotechnology, DOI: 10.1038/NNANO.2012.42

 

[ramonmercado]

Good results and the patients weren't turned into goo.

Drug-smuggling nanoparticles target tumours
http://www.newscientist.com/article/dn2 ... mours.html
18:25 05 April 2012 by Sara Reardon
Magazine issue 2860.

Drug-smuggling nanoparticles could be the latest recruits in the fight against cancer. The first results from early-stage trials show that cancer drugs couriered by nanoparticles may reduce the size of tumours in humans.

Researchers from BIND Biosciences in Boston filled nanoparticles with the cancer drug docetaxel and injected them into the blood of 17 people who had cancers that are normally resistant to the drug. Forty-two days later, two of the volunteers' tumours had shrunk in size significantly, and the rest of the volunteers' tumours had not grown.

When injected into the body, docetaxel doesn't discriminate between healthy and cancerous cells. However, the nanoparticles only released their payload when they reacted with molecules on the tumour's surface, so up to 80 per cent less of the drug needed to be injected to get the same amount into the tumour.

As a result, physicians should be able to up the concentration of the drug without worrying about toxic side effects, says Jeffrey Hrkach, senior vice-president at BIND. He says larger clinical trials are in the pipeline.

Journal reference: Science Translational Medicine, DOI: 10.1126/scitranslmed.3003651

 

[ramonmercado]

Like special-forces troops laser-tagging targets for a bomber pilot Hope it works as well on humans.

Nanoparticles home in on brain tumors, boost accuracy of surgical removal
http://phys.org/news/2012-04-nanopartic ... boost.html
April 15th, 2012 in Nanotechnology / Bio & Medicine

Like special-forces troops laser-tagging targets for a bomber pilot, tiny particles that can be imaged three different ways at once have enabled Stanford University School of Medicine scientists to remove brain tumors from mice with unprecedented accuracy.

In a study to be published online April 15 in Nature Medicine, a team led by Sam Gambhir, MD, PhD, professor and chair of radiology, showed that the minuscule nanoparticles engineered in his lab homed in on and highlighted brain tumors, precisely delineating their boundaries and greatly easing their complete removal. The new technique could someday help improve the prognosis of patients with deadly brain cancers.

About 14,000 people are diagnosed annually with brain cancer in the United States. Of those cases, about 3,000 are glioblastomas, the most aggressive form of brain tumor. The prognosis for glioblastoma is bleak: the median survival time without treatment is three months. Surgical removal of such tumors — a virtual imperative whenever possible — prolongs the typical patient's survival by less than a year. One big reason for this is that it is almost impossible for even the most skilled neurosurgeon to remove the entire tumor while sparing normal brain.

"With brain tumors, surgeons don't have the luxury of removing large amounts of surrounding normal brain tissue to be sure no cancer cells are left," said Gambhir, who is the Virginia and D.K. Ludwig Professor for Clinical Investigation in Cancer Research and director of the Molecular Imaging Program at Stanford. "You clearly have to leave as much of the healthy brain intact as you possibly can."

This is a real problem for glioblastomas, which are particularly rough-edged tumors. In these tumors, tiny fingerlike projections commonly infiltrate healthy tissues, following the paths of blood vessels and nerve tracts. An additional challenge is posed by micrometastases: minuscule tumor patches caused by the migration and replication of cells from the primary tumor. Micrometastases dotting otherwise healthy nearby tissue but invisible to the surgeon's naked eye can burgeon into new tumors.

Although brain surgery today tends to be guided by the surgeon's naked eye, new molecular imaging methods could change that, and this study demonstrates the potential of using high-technology nanoparticles to highlight tumor tissue before and during brain surgery.

The nanoparticles used in the study are essentially tiny gold balls coated with imaging reagents. Each nanoparticle measures less than five one-millionths of an inch in diameter — about one-sixtieth that of a human red blood cell.

"We hypothesized that these particles, injected intravenously, would preferentially home in on tumors but not healthy brain tissue," said Gambhir, who is also a member of the Stanford Cancer Institute. "The tiny blood vessels that feed a brain tumor are leaky, so we hoped that the spheres would bleed out of these vessels and lodge in nearby tumor material." The particles' gold cores, enhanced as they are by specialized coatings, would then render the particles simultaneously visible to three distinct methods of imaging, each contributing uniquely to an improved surgical outcome.

One of those methods, magnetic resonance imaging, is already frequently used to give surgeons an idea of where in the brain the tumor resides before they operate. MRI is well-equipped to determine a tumor's boundaries, but when used preoperatively it can't perfectly describe an aggressively growing tumor's position within a subtly dynamic brain at the time the operation itself takes place.

The Gambhir team's nanoparticles are coated with gadolinium, an MRI contrast agent, in a way that keeps them stably attached to the relatively inert spheres in a blood-like environment. (In a 2011 study published in Science Translational Medicine, Gambhir and his colleagues showed in small animal models that nanoparticles similar to those used in this new study, but not containing gadolinium, were nontoxic.)

A second, newer method is photoacoustic imaging, in which pulses of light are absorbed by materials such as the nanoparticles' gold cores. The particles heat up slightly, producing detectable ultrasound signals from which a three-dimensional image of the tumor can be computed. Because this mode of imaging has high depth penetration and is highly sensitive to the presence of the gold particles, it can be useful in guiding removal of the bulk of a tumor during surgery.

The third method, called Raman imaging, leverages the capacity of certain materials (included in a layer coating the gold spheres) to give off almost undetectable amounts of light in a signature pattern consisting of several distinct wavelengths. The gold cores' surfaces amplify the feeble Raman signals so they can be captured by a special microscope.
To demonstrate the utility of their approach, the investigators first showed via various methods that the lab's nanoparticles specifically targeted tumor tissue, and only tumor tissue.

Next, they implanted several different types of human glioblastoma cells deep into the brains of laboratory mice. After injecting the imaging-enhancing nanoparticles into the mice's tail veins, they were able to visualize, with all three imaging modes, the tumors that the glioblastoma cells had spawned.

The MRI scans provided good preoperative images of tumors' general shapes and locations. And during the operation itself, photoacoustic imaging permitted accurate, real-time visualization of tumors' edges, enhancing surgical precision.

But neither MRI nor photoacoustic imaging by themselves can distinguish healthy from cancerous tissue at a sufficiently minute level to identify every last bit of a tumor. Here, the third method, Raman imaging, proved crucial. In the study, Raman signals emanated only from tumor-ensconced nanoparticles, never from nanoparticle-free healthy tissue. So, after the bulk of an animal's tumor had been cleared, the highly sensitive Raman-imaging technique was extremely accurate in flagging residual micrometastases and tiny fingerlike tumor projections still holed up in adjacent normal tissue that had been missed on visual inspection. This, in turn, enabled these dangerous remnants' removal.

"Now we can learn the tumor's extent before we go into the operating room, be guided with molecular precision during the excision procedure itself and then immediately afterward be able to 'see' once-invisible residual tumor material and take that out, too," said Gambhir, who suggested that the nanoparticles' propensity to heat up on photoacoustic stimulation, combined with their tumor specificity, might also make it possible for them to be used to selectively destroy tumors. He also expressed optimism that this kind of precision could eventually be brought to bear on other tumor types.

Provided by Stanford University Medical Center

 

[ramonmercado]

Protecting us from over eager scientists, we really don't want to dissolve into pools of goo.

Nanotechnology-Related Safety and Ethics Problem Emerging
http://www.sciencedaily.com/releases/20 ... 000220.htm

ScienceDaily (Apr. 28, 2012) — A recent paper by Kathleen Eggleson, a research scientist in the Center for Nano Science and Technology (NDnano) at the University of Notre Dame, provides an example of a nanotechnology-related safety and ethics problem that is unfolding right now.

The world of nanotechnology, which involves science and engineering down at billionths-of-a-meter scales, might seem remote.

But like most new advances, the application of that technology to everyday experience has implications that can affect people in real ways.

If not anticipated, discussed or planned for, some of those implications might even be harmful.

The problem that Eggleson describes is that hospital-acquired infections are a persistent, costly and sometimes fatal issue. A patient goes in for one condition, say an injury, but ends up being infected by a microorganism picked up in the hospital itself. That microorganism might even have developed a resistance to conventional drug treatments.

The solution is that engineers are developing new and innovative ways of coating medical materials with nano-sized particles of silver, an element that has long been known for its antimicrobial properties. These particles are being applied to hard surfaces, like bedrails and doorknobs, and to fabrics, such as sheets, gowns and curtains, by a growing number of medical supply companies. And these new materials are proving effective.

"Nanosilver coatings have made life-saving differences to the properties of typical hospital items," Eggleson says. "Just this last December, a textile made by a Swiss company was the first nano-scale material approved as a pesticide by the EPA."

The possible new danger is that the vast majority of bacteria and other microorganisms are actually neutral, or even beneficial, to human life and a healthy environment. For example, some bacteria are needed to maintain appropriate levels of nitrogen in the air, and others, living inside the human body, are critical to both vitamin synthesis and digestion.

So overuse of nanosilver products, especially outside of clinical environments, could pose a danger to needed microorganisms, and enable resistant strains to flourish.

"Under most conditions, the preservation of microbial biodiversity is a benefit," explains Eggleson.

"In fact, those who would use these potent new antimicrobial technologies for frivolous uses, such as for odor control, work directly against the U.S. National Nanotechnology Initiative's goal of responsible nanotechnology development."

Eggleson came to the Center for Nano Science and Technology last year to study and prompt discussion of problems like these.

"NDnano is expanding its scope into studies of the societal impact of nanotechnology," explains Wolfgang Porod, Frank M. Freimann Professor of Electrical Engineering at Notre Dame and director of the center. "This is the background for bringing Kathy on board."

To facilitate such discussion, Eggleson initiated a monthly meeting group, called the Nano Impacts Intellectual Community, which brings together Notre Dame researchers from across campus, visiting scholars and authors from outside the university, and leaders from the local area to probe nanotechnology topics in depth.

The group has tackled such issues as the ethics of nanomedicine, the commercialization of nanotechnology products, and the interdisciplinary nature of nanotechnology research.

"I appreciate being a part of this on-going conversation," says Glenn Killoren, an attorney at Barnes & Thornburg LLP and a regular Nano Impacts attendee. "Nanotechnology isn't just something that happens in research labs anymore. It's a small but growing part of our lives, and both scientists and non-scientists need to think about its effects."

Eggleson and NDnano faculty have also met with a number of local middle school and high school teachers who feature nanotechnology in their lesson plans. Moreover, the center supports Ivy Tech Community College-North Central's program to train aspiring nanotechnology technicians.

"We try to do as much as we can to engage the community this exciting area," says Eggleson.

NDnano is one of the leading nanotechnology centers in the world. Its mission is to study and manipulate the properties of materials and devices, as well as their interfaces with living systems, at the nano-scale.

The center's expanding work on the societal impacts of nanotechnology has been made possible, in part, by one of the university's Strategic Research Investments (SRIs), which represent a commitment of internal funds and other resources, supplementing funding from external grants and gifts, to advance excellence in research.

In addition, Nano Impacts is supported by the Office of the Provost's Initiative on Building Intellectual Community.

 

[ramonmercado]

Sounds promising, I hopr they can move on to human trials soon.

Nanoparticles cut off 'addicted' tumors from source of their survival
http://medicalxpress.com/news/2012-05-n ... vival.html
May 28th, 2012 in Cancer

(Medical Xpress) -- Yale biologists and engineers have designed drug-loaded nanoparticles that target the soft underbelly of many types of cancer — a tiny gene product that tumors depend upon to replicate and survive.

The novel therapy successfully stopped lymphoma in mice when injected directly into tumors, the researchers report in the Proceedings of the National Academy of Sciences, published the week of May 28.

The interdisciplinary collaboration takes advantage of a new concept in cancer research — that tumors become “addicted” to a few genetic abnormalities they need to survive, grow, and spread throughout the body.

“Thousands of genes are mis-expressed in cancer, but so far cancer researchers have only found 10 or so that cancer cells absolutely need to survive,” said Frank Slack, professor of molecular, cellular, and developmental biology, director of the Cancer Genetics and Genomics Program for the Yale Cancer Center, and senior author of the study.

Slack’s lab studies microRNAs, or small pieces of genetic material that determine when and where much larger genes that code for proteins are used. One of these miRNAs, miR-155, helps regulate cell survival and is overactive in many forms of cancer. For instance, mice with excessive amounts of miR-155 develop lymphoma tumors.

One of Slack’s graduate students collaborated with a student working in the lab of Mark Saltzman, the Goizueta Foundation Professor of Chemical and Biomedical Engineering and Yale Cancer Center researcher, about ways to use nanoparticles to help block actions of miR-155 in mice with lymphoma. The team discovered that injecting nanoparticles that deliver a compound that specifically targets miR-155 into tumors stopped them from growing in mice.

Slack pointed out that miR-155 is also overactive in lung cancer and many other treatment-resistant forms of the disease.

“At this point, we want to improve the technique so we can load even more of this compound into the nanoparticles and make it easier for them to enter tumor cells,” Slack said. “Ultimately, we would like to take this to human clinical trials for difficult-to-treat cancers.”

Imran A. Babar and Christopher J. Cheng were co-lead authors of the paper. Other Yale authors are Carmen J. Booth, Xianping Liang, and Joanne B. Weidhaas.

Provided by Yale University

 

[ramonmercado]

Looks good, solar energy has sort of shrunk into the background.

Nano Breakthrough Paves Way for Super Cheap Solar Panels
http://www.wired.com/wiredenterprise/20 ... lar-panel/
By Klint FinleyEmail Author August 1, 2012 | 12:00 pm | Categories: Energy

Two things hold back the mass adoption of solar energy as a source of sustainable energy. One is the need to store and transmit excess power, a problem people like Danielle Fong are working on solving by developing innovative new ways to store power. The other is the high cost of solar panels. One of the reasons solar panels are so expensive is that it’s tricky to extract electric currents from semiconductors, the materials used to convert solar radiation into electrical energy.

Up til now, this could only be done with a few materials — usually silicon. But a new breakthrough will enable manufacturers to make efficient photovoltaics using almost any semiconductor, including cheap and abundant materials like metal oxides, sulfides, and phosphides.

A typical photovoltaic cell is built with silicon and treated with chemicals. This treatment is called “doping,” and it creates the driving force needed to extract power from the cell. Photovoltaics can also be built with cheaper materials but many of these can’t be doped chemically. But a method developed by Professor Alex Zettl’s research group at Lawrence Berkeley National Laboratory and University of California at Berkeley makes it possible to dope nearly any semiconductor by applying an electric field instead of chemicals. The method is described in a paper published in the journal Nano Letters.


According to Will Regan, lead author of the paper, it’s long been known in the transistor industry that applying an electric field could be used for doping, but existing electrode designs were incompatible with photovoltaic cells. What the researchers discovered is a new way of designing electrodes to allow an electric field to pass through and dope the semiconductor.

“Graphene was the inspiration,” Regan explains. Graphene is a highly conductive, one-atom-thick sheet of carbon. The team at the Zettl Research Group began experimenting with graphene as a transparent electrode for silicon photovoltaics and realized they could directly influence the semiconductor with an applied electric field. Once they’d realized that a very thin conductor could be used, they realized a very narrow one would be suitable as well. The paper describes two ways of building the electrodes: one with graphene, the other with extremely narrow nanowires.

While there’s a fair amount of inertia in the solar manufacturing industry, Regan is optimistic that this new method will be adopted, noting that these cells could be made using simple and cost-effective tweaks to existing fabrication processes.

 

[ramonmercado]

Hopefully it will so0n change from "may" to being a reality.

Nanofibers may help treat heart attacks
August 10th, 2012 in Cardiology

(Medical Xpress) -- Cardiovascular diseases kill over 17 million people a year globally, according to the World Health Organization, and many more suffer heart attacks but recover. Even those who do recover are more prone to suffer heart failure or future heart attacks because the heart tissue is damaged. Attempts to produce effective therapies to promote repair and regeneration of heart tissues and blood vessels have so far mostly been unpromising.

Now new research by scientists in Taiwan and the US has found a promising treatment involving vascular endothelial growth factor (VEGF), which promotes blood vessel re-growth. Previous attempts to develop a therapy based on VEGF were limited by the fact that the growth factor is rapidly washed out of the heart by the blood flow, but the new research solves this problem.

The team used a gel containing a lattice of self-assembling peptide nanofibers in combination with VEGF and found that the scaffold-like structure of the nanofibers held the VEGF in place, enabling it to be released slowly over a period of weeks.

The researchers, led by Assistant Professor Patrick C. H. Hsieh of the Institute of Biomedical Engineering, at the National Cheng Kung University, in Tainan, Taiwan, induced heart attacks in rats and then injected a combination of the nanofibers along with various doses of VEGF in the rats’ hearts.

They found that the combination improved heart health and provided an environment that promoted growth of new blood vessels, repair of damaged tissues and growth of new tissue. Dr. Hsieh, a cardiac surgeon, said the nanofibers provide an effective environment for attracting the stem cells that repair the damage and regenerate blood capillaries and even new arteries.

After 28 days the hearts of treated animals showed a much greater degree of repair and re-growth than the hearts of control animals. Arterial growth was five times greater in the treated animals, new heart muscle was being formed, and areas of weak, scarred tissue, were reduced. The controls received either VEGF alone or the nanofibers alone. The same beneficial effects were demonstrated in rats and pigs, and no harmful side effects were noted in either species.

The paper was published in the journal Science Translational Medicine. In an accompanying article in the journal, Karen Christman of the University of California San Diego, said the study could lead to therapies to help human heart attack patients to recover more quickly and have improved quality of life during the recovery period. More research is needed to study the long-term effects and to determine the “optimal time window,” for administering the treatment, Dr Hsieh said.

More information: Y.-D. Lin, C.-Y. Luo, Y.-N. Hu, M.-L. Yeh, Y.-C. Hsueh, M.-Y. Chang, D.-C. Tsai, J.-N. Wang, M.-J. Tang, E. I. Wei, M. L. Springer, P. C. Hsieh, Instructive Nanofiber Scaffolds with VEGF Create a Microenvironment for Arteriogenesis and Cardiac Repair. Sci. Transl. Med. 4, 146ra109 (2012).

ABSTRACT

Angiogenic therapy is a promising approach for tissue repair and regeneration. However, recent clinical trials with protein delivery or gene therapy to promote angiogenesis have failed to provide therapeutic effects. A key factor for achieving effective revascularization is the durability of the microvasculature and the formation of new arterial vessels. Accordingly, we carried out experiments to test whether intramyocardial injection of self-assembling peptide nanofibers (NFs) combined with vascular endothelial growth factor (VEGF) could create an intramyocardial microenvironment with prolonged VEGF release to improve post-infarct neovascularization in rats. Our data showed that when injected with NF, VEGF delivery was sustained within the myocardium for up to 14 days, and the side effects of systemic edema and proteinuria were significantly reduced to the same level as that of control. NF/VEGF injection significantly improved angiogenesis, arteriogenesis, and cardiac performance 28 days after myocardial infarction. NF/VEGF injection not only allowed controlled local delivery but also transformed the injected site into a favorable microenvironment that recruited endogenous myofibroblasts and helped achieve effective revascularization. The engineered vascular niche further attracted a new population of cardiomyocyte-like cells to home to the injected sites, suggesting cardiomyocyte regeneration. Follow-up studies in pigs also revealed healing benefits consistent with observations in rats. In summary, this study demonstrates a new strategy for cardiovascular repair with potential for future clinical translation.

© 2012 Medical Xpress

"Nanofibers may help treat heart attacks." August 10th, 2012. http://medicalxpress.com/news/2012-08-n ... heart.html

 

[ramonmercado]

Once again this looks as if it might deliver something, hope so. NanoTech might turn out to be the latest dream which failed. Unless we can build flying cars with it.

Researchers demonstrate 'giant' forces in super-strong nanomaterials
September 22nd, 2012 in Physics / Optics & Photonics

Missouri S&T researchers' modeling of stacked nanoscale slot waveguides made of metamaterials shows an optical force 100 to 1,000 times greater than conventional slot waveguides made from silicon.

(Phys.org)—In a study that could lead to advances in the emerging fields of optical computing and nanomaterials, researchers at Missouri University of Science and Technology report that a new class of nanoscale slot waveguides pack 100 to 1,000 times more transverse optical force than conventional silicon slot waveguides

The findings could lead to advances in developing optical computers, sensors or lasers, say researchers Dr. Jie Gao and Dr. Xiaodong Yang, both assistant professors of mechanical engineering at Missouri S&T.

In their research article, published in the Sept. 24 issue of Optics Express, Gao and Yang describe the unusual optical and mechanical properties of nanometer-scale metal-dielectric structures called metamaterials. The researchers created computer simulations of nanometer-scale models of metamaterial slot waveguides, which are structures designed to channel beams of light from one area to another. Waveguides function like tiny filaments or the wires of an integrated circuit, but on a much smaller scale.

For their study, the Missouri S&T researchers simulated slot waveguides made of layered structures of a metal (in this case, silver) and a dielectric material (germanium), arranged like the alternating bread and meat in a club sandwich. A nanometer – visible only with the aid of a high-power electron microscope – is one billionth of a meter, and some nanomaterials are only a few atoms in size.

Gao and Yang simulated what would happen with modeled identical waveguides – each 40 nanometers wide and 30 nanometers tall – that were stacked with a tiny air gap between them. They then measured the transverse optical force between the two waveguides. Optical force refers to the way beams of light can be made to attract or repel each other, as magnets do.

In their experiments on the simulated metamaterials, the Missouri S&T researchers found that "the transverse optical forces in slot waveguides of hyperbolic metamaterials can be over two orders of magnitude stronger than that in conventional dielectric slot waveguides." For this reason, Gao and Yang describe the magnitude as "giant" in the title of their Optics Express article, "Giant transverse optical forces in nanoscale slot waveguides of hyperbolic metamaterials."

"The calculation on realistic metal-dielectric multilayer structures indicates that the predicted giant optical forces are achievable in experiments," the researchers explain in their Optics Express article. They add that their finding "will open the door for various optomechanical applications in nanoscale, such as optical nanoelectromechanical systems, optical sensors and actuators."

By experimenting with materials at the nanometer level, researchers often find that even common materials exhibit unusual properties. For example, metals developed at the nanometer scale may have fewer defects and could lead to stronger materials for construction. Semiconductors and magnetic materials developed at the nanometer scale may have different properties than the bulk material.

The team also recently described the optical properties of a single metamaterial waveguide in the Journal of the Optical Society of America. The paper is titled "Nanoscale metamaterial optical waveguides with ultrahigh refractive indices".

Earlier this year, Yang was the lead author of an article published in Nature Photonics that described how nanoscale three-dimensional optical cavities made from metamaterials can generate the most powerful nanolaser beams to date. The Nature Photonics paper described how this new class of optical cavities holds promise for other technologies, including photonic integrated circuits, LEDs, quantum optics, nonlinear optics and optical sensing.

Gao and Yang plan to move their research from modeling and simulation to actual fabrication of metamaterials. Working with the Materials Research Center at Missouri S&T, the two are able to use a focused ion beam (FIB) scanning electron microscope to modify materials being analyzed. But the two also hope to develop a nanofabrication facility at Missouri S&T.

More information: www.opticsinfobase.org/oe/abstract.cfm? ... 0-20-22372

Provided by Missouri University of Science and Technology

"Researchers demonstrate 'giant' forces in super-strong nanomaterials." September 22nd, 2012.
http://phys.org/news/2012-09-giant-supe ... rials.html

 

[ramonmercado]

Looks promising just hope they get beyond micrometers.

Assembly of Nano-Machines Mimics Human Muscle
http://www.sciencedaily.com/releases/20 ... 100940.htm

Researchers have succeeded in synthesizing an assembly of thousands of nano-machines capable of producing a coordinated contraction movement extending up to around ten micrometers, like the movements of muscular fibers. (Credit: © microcozm / Fotolia)

ScienceDaily (Oct. 23, 2012) — For the first time, an assembly of thousands of nano-machines capable of producing a coordinated contraction movement extending up to around ten micrometers, like the movements of muscular fibers, has been synthesized by a CNRS team from the Institut Charles Sadron.

This innovative work, headed by Nicolas Giuseppone, professor at the Université de Strasbourg, and involving researchers from the Laboratoire de Matière et Systèmes Complexes (CNRS/Université Paris Diderot), provides an experimental validation of a biomimetic approach that has been conceptualized for some years in the field of nanosciences. This discovery opens up perspectives for a multitude of applications in robotics, in nanotechnology for the storage of information, in the medical field for the synthesis of artificial muscles or in the design of other materials incorporating nano-machines (endowed with novel mechanical properties). This work has been published in the online version of the journal Angewandte Chemie International Edition.

Nature manufactures numerous machines known as "molecular." Highly complex assemblies of proteins, they are involved in essential functions of living beings such as the transport of ions, the synthesis of ATP (the "energy molecule"), and cell division. Our muscles are thus controlled by the coordinated movement of these thousands of protein nano-machines, which only function individually over distances of the order of a nanometer. However, when combined in their thousands, such nano-machines amplify this telescopic movement until they reach our scale and do so in a perfectly coordinated manner. Even though synthetic chemists have made dazzling progress over the last few years in the manufacture of artificial nano-machines (the mechanical properties of which are of increasing interest for research and industry), the coordination of several of these machines in space and in time hitherto remained an unresolved problem.

Not anymore: for the first time, Giuseppone's team has succeeded in synthesizing long polymer chains incorporating, via supramolecular bonds, thousands of nano-machines each capable of producing linear telescopic motion of around one nanometer. (A supramolecular bond is an interaction between different molecules that is not based on a traditional "covalent" chemical bond but instead on what are known as "weak interactions," thereby constituting complex molecular structures.) Under the influence of pH, their simultaneous movements allow the whole polymer chain to contract or extend over about 10 micrometers, thereby amplifying the movement by a factor of 10,000, along the same principles as those used by muscular tissues. Precise measurements of this experimental feat have been performed in collaboration with the team led by Eric Buhler, a physicist specialized in radiation scattering at the Laboratoire Matière et Systèmes Complexes (CNRS/Université Paris Diderot).

These results, obtained using a biomimetic approach, could lead to numerous applications for the design of artificial muscles, micro-robots or the development of new materials incorporating nano-machines endowed with novel multi-scale mechanical properties.

Story Source:

The above story is reprinted from materials provided by Centre national de la recherche scientifique (CNRS).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Guangyan Du, Emilie Moulin, Nicolas Jouault, Eric Buhler, Nicolas Giuseppone. Muscle-like Supramolecular Polymers: Integrated Motion from Thousands of Molecular Machines. Angewandte Chemie, 2012; DOI: 10.1002/ange.201206571

 

[ramonmercado]

First it replaces our faithful friends, then, having gained our trust it breaks us down for raw materials.

Nanotech Device Mimics Dog's Nose to Detect Explosives
http://www.sciencedaily.com/releases/20 ... 100421.htm

Concept illustration of the microscale free-surface microfluidic channel as it concentrates vapor molecules that bind to nanoparticles inside a chamber. A laser beam detects the nanoparticles, which amplify a spectral signature of the detected molecules. (Credit: Image courtesy of University of California - Santa Barbara)

ScienceDaily (Nov. 20, 2012) — Portable, accurate, and highly sensitive devices that sniff out vapors from explosives and other substances could become as commonplace as smoke detectors in public places, thanks to researchers at University of California, Santa Barbara.

Researchers at UCSB, led by professors Carl Meinhart of mechanical engineering and Martin Moskovits of chemistry, have designed a detector that uses microfluidic nanotechnology to mimic the biological mechanism behind canine scent receptors. The device is both highly sensitive to trace amounts of certain vapor molecules, and able to tell a specific substance apart from similar molecules.

"Dogs are still the gold standard for scent detection of explosives. But like a person, a dog can have a good day or a bad day, get tired or distracted," said Meinhart. "We have developed a device with the same or better sensitivity as a dog's nose that feeds into a computer to report exactly what kind of molecule it's detecting." The key to their technology, explained Meinhart, is in the merging of principles from mechanical engineering and chemistry in a collaboration made possible by UCSB's Institute for Collaborative Biotechnologies.

Results published this month in Analytical Chemistry show that their device can detect airborne molecules of a chemical called 2,4-dinitrotoluene, the primary vapor emanating from TNT-based explosives. The human nose cannot detect such minute amounts of a substance, but "sniffer" dogs have long been used to track these types of molecules. Their technology is inspired by the biological design and microscale size of the canine olfactory mucus layer, which absorbs and then concentrates airborne molecules.

"The device is capable of real-time detection and identification of certain types of molecules at concentrations of 1 ppb or below. Its specificity and sensitivity are unparalleled," said Dr. Brian Piorek, former mechanical engineering doctoral student in Meinhart's laboratory and Chief Scientist at Santa Barbara-based SpectraFluidics, Inc . The technology has been patented and exclusively licensed to SpectraFluidics, a company that Piorek co-founded in 2008 with private investors.

"Our research project not only brings different disciplines together to develop something new, but it also creates jobs for the local community and hopefully benefits society in general," commented Meinhart.

Packaged on a fingerprint-sized silicon microchip and fabricated at UCSB's state-of-the-art cleanroom facility, the underlying technology combines free-surface microfluidics and surface-enhanced Raman spectroscopy (SERS) to capture and identify molecules. A microscale channel of liquid absorbs and concentrates the molecules by up to six orders of magnitude. Once the vapor molecules are absorbed into the microchannel, they interact with nanoparticles that amplify their spectral signature when excited by laser light. A computer database of spectral signatures identifies what kind of molecule has been captured.

"The device consists of two parts," explained Moskovits. "There's a microchannel, which is like a tiny river that we use to trap the molecules and present them to the other part, a mini spectrometer powered by a laser that detects them. These microchannels are twenty times smaller than the thickness of a human hair."

"The technology could be used to detect a very wide variety of molecules," said Meinhart. "The applications could extend to certain disease diagnosis or narcotics detection, to name a few."

Moskovits added, "The paper we published focused on explosives, but it doesn't have to be explosives. It could detect molecules from someone's breath that may indicate disease, for example, or food that has spoiled."

The fundamental research was developed through an interdisciplinary collaboration between Professors Meinhart and Moskovits, and carried out by former doctoral researchers Dr. Piorek and Dr. Seung-Joon Lee. Their project was funded in part by UCSB's Institute for Collaborative Biotechnologies through the Army Research Office and DARPA.

Story Source:

The above story is reprinted from materials provided by University of California - Santa Barbara.

Journal Reference:

Brian D. Piorek, Seung Joon Lee, Martin Moskovits, Carl D. Meinhart. Free-Surface Microfluidics/Surface-Enhanced Raman Spectroscopy for Real-Time Trace Vapor Detection of Explosives. Analytical Chemistry, 2012; 84 (22): 9700 DOI: 10.1021/ac302497y

 

[ramonmercado]

Yet another promise. Will it deliver? I'm getting cynical about nanotech again.

Flexible, Nanoscale 'Bed of Nails' Created for Possible Drug Delivery
http://www.sciencedaily.com/releases/20 ... 101522.htm

This image shows carbon nanofibers embedded in the elastic membrane. (Credit: Image courtesy of North Carolina State University)

Jan. 15, 2013 — Researchers at North Carolina State University have come up with a technique to embed needle-like carbon nanofibers in an elastic membrane, creating a flexible "bed of nails" on the nanoscale that opens the door to development of new drug-delivery systems.

The research community is interested in finding new ways to deliver precise doses of drugs to specific targets, such as regions of the brain. One idea is to create balloons embedded with nanoscale spikes that are coated with the relevant drug. Theoretically, the deflated balloon could be inserted into the target area and then inflated, allowing the spikes on the balloon's surface to pierce the surrounding cell walls and deliver the drug. The balloon could then be deflated and withdrawn.

But to test this concept, researchers first needed to develop an elastic material that is embedded with these aligned, nanoscale needles. That's where the NC State research team came in.

"We have now developed a way of embedding carbon nanofibers in an elastic silicone membrane and ensuring that the nanofibers are both perpendicular to the membrane's surface and sturdy enough to impale cells," says Dr. Anatoli Melechko, an associate professor of materials science and engineering at NC State and co-author of a paper on the work.

The researchers first "grew" the nanofibers on an aluminum bed, or substrate. They then added a drop of liquid silicone polymer. The polymer, nanofibers and substrate were then spun, so that centrifugal force spread the liquid polymer in a thin layer between the nanofibers -- allowing the nanofibers to stick out above the surface. The polymer was then "cured," turning the liquid polymer into a solid, elastic membrane. Researchers then dissolved the aluminum substrate, leaving the membrane embedded with the carbon nanofibers "needles."

"This technique is relatively easy and inexpensive," says Melechko, "so we are hoping this development will facilitate new research on targeted drug-delivery methods."

The research was supported by the National Science Foundation and the Department of Defense, Defense Threat Reduction Agency.

Story Source:

The above story is reprinted from materials provided by North Carolina State University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Ryan C. Pearce, Justin G Railsback, Bryan D Anderson, Mehmet F Sarac, Timothy E Mcknight, Joseph B. Tracy, Anatoli V Melechko. Transfer of Vertically Aligned Carbon Nanofibers to Polydimethylsiloxane (PDMS) while Maintaining their Alignment and Impalefection Functionality. ACS Applied Materials & Interfaces, 2013; : 130102201039009 DOI: 10.1021/am302501z
2013, from http://www.sciencedaily.com­ /releases/2013/01/130115101522.htm

 

[ramonmercado]

Ancient Nanotech.

Goblet tricks suggests ancient Romans were first to use nanotechnology
August 27th, 2013 in Nanotechnology / Nanomaterials

Credit: The Trustees of the British Museum

Credit: The Trustees of the British Museum

(Phys.org) —Recent evidence suggests that the Roman craftsmen who created the Lycurgus Cup, a glass drinking goblet, used nanotechnology to cause the goblet to change color under different lighting. The cup's unique properties were first noted when it was brought to a museum in the 1950s—it wasn't until 1990, however, that researchers figured out how the color changers were brought about.

The goblet was created approximately 1,600 years ago, using a process whereby very tiny gold and silver particles were embedded in the glass. In normal lighting, the glass appears to have a jade background. When lit from behind, however, the green parts suddenly look ruby red. This is all courtesy of the way electrons vibrate when struck by photons—something the Romans could not have known. Yet, because other goblet pieces have been found with the very same mixture, it's clear they knew they were on to something. They actually used the color changing effects to create stories. The Lycurgus Cup, for example, depicts the story of King Lycurgus as he is caught up in a tangle of grapevines—penance for treachery committed against Dionysus, the god of wine in Greek mythology.

Researchers speculate that the Romans simply ground the metal particles until it would take a thousand of them to match the size of single sand grain, then mixed them in with the hot liquid glass. But that wasn't the end of the story: the Romans created a goblet such as the Lycurgus Cup, by carving it from a single block. That means they also understood that different thicknesses of the glass would exhibit different coloring as well.
New research has suggested that the cup also changes colors when liquid is poured into it (although the researchers did not do so as it might have caused damage). Instead, they undertook lab experiments to replicate the makeup of the cup then applied various liquids. Their results suggest the cup might have displayed a variety of colors depending on which sort of beverage was poured into to it.

Researchers are just now, all these years later, learning about such color changing properties of materials with embedded nanoparticles. The hope is that these properties can be exploited to perform chemistry or medical tests cheaply and quickly by displaying different colors under different conditions.

More information: via Smithsonianmag

© 2013 Phys.org

"Goblet tricks suggests ancient Romans were first to use nanotechnology." August 27th, 2013. http://phys.org/news/2013-08-goblet-anc ... ology.html

 

[Mythopoeika]

There's quite a lot of old Roman glass around that is iridescent.
It's happened partly as a result of trace chemicals in the glass and prolonged immersion in water (i.e. in a lake or river).
Wonder if something like this happened here?

 

[Mythopoeika]

There's quite a lot of old Roman glass around that is iridescent.
It's happened partly as a result of trace chemicals in the glass and prolonged immersion in water (i.e. in a lake or river).
Wonder if something like this happened here?