Two sensors in one: Nanoparticles that enable both MRI and fluorescent imaging could monitor cancer, other diseases

November 18, 2014 Source: Massachusetts Institute of Technology

MIT chemists have developed new nanoparticles that can simultaneously perform magnetic resonance imaging (MRI) and fluorescent imaging in living animals. Such particles could help scientists to track specific molecules produced in the body, monitor a tumor’s environment, or determine whether drugs have successfully reached their targets.

In a paper appearing in the Nov. 18 issue of Nature Communications, the researchers demonstrate the use of the particles, which carry distinct sensors for fluorescence and MRI, to track vitamin C in mice. Wherever there is a high concentration of vitamin C, the particles show a strong fluorescent signal but little MRI contrast. If there is not much vitamin C, a stronger MRI signal is visible but fluorescence is very weak.

Future versions of the particles could be designed to detect reactive oxygen species that often correlate with disease, says Jeremiah Johnson, an assistant professor of chemistry at MIT and senior author of the study. They could also be tailored to detect more than one molecule at a time.

MIT chemists have developed new nanoparticles that can simultaneously perform magnetic resonance imaging (MRI) and fluorescent imaging in living animals.

Credit: Illustration by Christine Daniloff/MIT

[Click to enlarge image]

“You may be able to learn more about how diseases progress if you have imaging probes that can sense specific biomolecules,” Johnson says.

Dual action

Johnson and his colleagues designed the particles so they can be assembled from building blocks made of polymer chains carrying either an organic MRI contrast agent called a nitroxide or a fluorescent molecule called Cy5.5.

When mixed together in a desired ratio, these building blocks join to form a specific nanosized structure the authors call a branched bottlebrush polymer. For this study, they created particles in which 99 percent of the chains carry nitroxides, and 1 percent carry Cy5.5.

Nitroxides are reactive molecules that contain a nitrogen atom bound to an oxygen atom with an unpaired electron. Nitroxides suppress Cy5.5’s fluorescence, but when the nitroxides encounter a molecule such as vitamin C from which they can grab electrons, they become inactive and Cy5.5 fluoresces.

Nitroxides typically have a very short half-life in living systems, but University of Nebraska chemistry professor Andrzej Rajca, who is also an author of the new Nature Communications paper, recently discovered that their half-life can be extended by attaching two bulky structures to them. Furthermore, the authors of the Nature Communications paper show that incorporation of Rajca’s nitroxide in Johnson’s branched bottlebrush polymer architectures leads to even greater improvements in the nitroxide lifetime. With these modifications, nitroxides can circulate for several hours in a mouse’s bloodstream — long enough to obtain useful MRI images.

The researchers found that their imaging particles accumulated in the liver, as nanoparticles usually do. The mouse liver produces vitamin C, so once the particles reached the liver, they grabbed electrons from vitamin C, turning off the MRI signal and boosting fluorescence. They also found no MRI signal but a small amount of fluorescence in the brain, which is a destination for much of the vitamin C produced in the liver. In contrast, in the blood and kidneys, where the concentration of vitamin C is low, the MRI contrast was maximal.

Mixing and matching

The researchers are now working to enhance the signal differences that they get when the sensor encounters a target molecule such as vitamin C. They have also created nanoparticles carrying the fluorescent agent plus up to three different drugs. This allows them to track whether the nanoparticles are delivered to their targeted locations.

“That’s the advantage of our platform — we can mix and match and add almost anything we want,” Johnson says.

These particles could also be used to evaluate the level of oxygen radicals in a patient’s tumor, which can reveal valuable information about how aggressive the tumor is.

“We think we may be able to reveal information about the tumor environment with these kinds of probes, if we can get them there,” Johnson says. “Someday you might be able to inject this in a patient and obtain real-time biochemical information about disease sites and also healthy tissues, which is not always straightforward.”

Steven Bottle, a professor of nanotechnology and molecular science at Queensland University of Technology, says the most impressive element of the study is the combination of two powerful imaging techniques into one nanomaterial.

“I believe this should deliver a very powerful, metabolically linked, multi-combination imaging modality which should provide a highly useful diagnostic tool with real potential to follow disease progression in vivo,” says Bottle, who was not involved in the study.

The research was funded by the National Institutes of Health, the Department of Defense, the National Science Foundation, and the Koch Institute for Integrative Cancer Research.

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Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by Anne Trafton. Note: Materials may be edited for content and length.

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Journal Reference:

1. Molly A. Sowers, Jessica R. McCombs, Ying Wang, Joseph T. Paletta, Stephen W. Morton, Erik C. Dreaden, Michael D. Boska, M. Francesca Ottaviani, Paula T. Hammond, Andrzej Rajca, Jeremiah A. Johnson. Redox-responsive branched-bottlebrush polymers for in vivo MRI and fluorescence imaging. Nature Communications, 2014; 5: 5460 DOI: 10.1038/ncomms6460

Searching for Global Water and Food Solutions: MIT

John Lienhard leads coordinated interdisciplinary research efforts to confront resource challenges at the Abdul Latif Jameel World Water and Food Security Lab.

MIT Industrial Liaison Program
November 4, 2014

 

 

 

As world population continues to grow, so does the need for water and food. It would be easy if the fix were laying down more pipes and cultivating more crops. But it’s not that simple. The global climate is becoming unevenly warmer and more people are moving into cities. Both conditions put stress onto already-limited resources. These complex issues need complex solutions, and, for that, MIT has created the Abdul Latif Jameel World Water and Food Security Lab.

Started in the fall of 2014 under the direction of Professor John Lienhard, the lab will be able to support and coordinate research all over campus, helping at once industries trying to improve their productivity and localities trying to thrive. As Lienhard says, it’s the interdisciplinary approach, coupled with MIT’s unique capabilities, that will set the lab apart and bring innovative solutions to bear.

Taking on each region

The lab was established through a gift from Mohammed Abdul Latif Jameel ’78, a civil engineering graduate, with the intent of tackling world food and water issues and the interplay of factors that affect them. As an example, in the Arabian Gulf States, conditions are arid with little agricultural capacity. Most of the water comes from desalinated seawater, and much of the food is imported. It’s an area that will become warmer and drier and be subjected to extreme weather in the coming years, with a population that is rapidly growing, Lienhard says.

Along the equator, climate change will particularly affect agricultural regions. Some of these areas are going to warm faster, but Lienhard says that the bigger issue is that food productivity will shift, making some crops less viable in equatorial areas and more productive closer to the poles, changing what can be grown, and turning strong producers into weaker ones and vice versa. Since food always requires water, one question is whether changing management practices can be the answer to increased production. Fertilizer is a known commodity and would be an easy solution, but, as Lienhard says, it brings with it runoff into waterways and resulting damage to ecosystems.

These specific considerations are reflective of the inherent nature of what the lab faces. “Each of these issues is a regional problem that needs to be looked at in its own context,” says Lienhard, adding, “There is no single answer that’s going to come from a neat invention and a new technology.”

The lab will address this complexity by engaging faculty from across schools, including science, engineering, architecture and urban planning, humanities, arts and social sciences, and management, and by drawing upon work being done in various labs — for example, graphene membranes that can be used for desalination and wireless communication signals that can identify pipe leaks. “When we put people from different disciplines together, we get radically new ideas and approaches to the problems,” he says.

The entry into food

One particular opportunity the lab will provide MIT is having a clear presence in solving global food needs. The impact of population growth is a central issue. In 1960, the world had 3 billion people. Today, it’s 7 billion, and in 2050, the estimate is 9 billion. With that three-fold increase and ongoing development, 50, possibly 70, percent more food will be needed by 2050 than is produced today, Lienhard says. The challenge is that more than one-third of the world’s ice-free land is already being used for farming. Since converting more land to farms through practices such as cutting down rainforests isn’t viable, the answer may lie in more efficient production techniques or different food choices. As he says, one-third of all crops are used for livestock, and producing beef takes 15 times more water than producing an equivalent amount of grain.

Another issue is the rise in urbanization. More than 50 percent of the population already lives in cities. By 2050, it’s estimated that 86 percent of the developed world and 64 percent of the developing one will be there, Lienhard says. Most food, accordingly, is consumed in cities, and so another question is whether urban agriculture can be developed as a water and energy efficient approach to some portion of the food supply.

Many of these issues are known and studied, but a course of action hasn’t been established, let alone enacted. While the lab will be able to identify already-existing food technology on campus to address a problem, one other benefit is it can help identify work that wasn’t conceived for food-related uses but which nonetheless can be applied.

Take food spoilage: One MIT program in nanotechnology has developed sensors that can detect chemical weapons. But these sensors can also be used to detect ripening or rotting food. This could provide the chance to improve food distribution and reduce waste and spoilage along the supply chain. If that can be done, a significant obstacle can be cleared, since estimates suggest that wasted food is four times the amount needed to feed the world’s hungry people, Lienhard says.

In search of partners

The next step, and the essential one, is collaboration, not only within the university but also with industry. Lienhard says that the lab is looking for partners around the world who can develop and implement new water and food technologies and approaches. But more than that, the lab will help partners address their own business challenges. Some companies want to make their environmental footprints smaller. Others face product struggles in international markets, such as beverages and water. They have to contend with a different quality while also competing for it with locals. Lienhard says the lab can help find an equitable balance between commerce and sharing resources for domestic use.

Because the lab is new, Lienhard says there’s an unknown element to what the work will look like. But for potential partners, there is also a certainty. “They get MIT,” says Lienhard. They know, in other words, that they’ll be working in a context where there are world-recognized faculty members, a large population of graduate and postdoctoral researchers, approximately 120 United States patents issued to Institute-related projects annually, and 20 spinoff companies per year, he says.

There is also the overall guiding philosophy of MIT’s approach. It’s a place that doesn’t keep its work in the lab but instead focuses on translating research to real-world use. Supplying sufficient water and food as the population grows and the climate changes is a large task, but Lienhard says that’s precisely the nature of what MIT does. “We take basic science. We apply it to human needs, and we solve problems.”

NIST Offers Electronics Industry New Tools & Methods to Snoop on Self-Organizing Molecules

NIST Offers Electronics Industry Two Ways to Snoop on Self-Organizing Molecules

From NIST Tech Beat: October 22, 2014
*

A few short years ago, the idea of a practical manufacturing process based on getting molecules to organize themselves in useful nanoscale shapes seemed … well, cool, sure, but also a little fantastic.

Now the day isn’t far off when your cell phone may depend on it. Two recent papers emphasize the point by demonstrating complementary approaches to fine-tuning the key step: depositing thin films of a uniquely designed polymer on a template so that it self-assembles into neat, precise, even rows of alternating composition just 10 or so nanometers wide.

Computer simulations of two possible morphologies of a block copolymer film demonstrate the need for an accurate 3D imaging tool. Red and blue areas represent the two different phases of the polymer film, seen from the side.

Transmission electron microscope (TEM) tomography provides a nanoscale, 3D visualization of the structure of a templated block copolymer. The purple features are silica posts fabricated by electron-beam lithography that direct the self-assembly of the copolymer. The material self-assembles to form two orthogonal layers of cylinders (green).

Credit: Winterstein/NIST
View hi-resolution image

Each phase is about 12 nm wide. Viewed from the top, both would appear to have evenly separated rows of the “red” phase, the bottom sample in fact has an unwanted horizontal band that will disrupt the pattern transfer. Soft X-ray scattering data can distinguish the two.

The work by researchers at the National Institute of Standards and Technology (NIST), the Massachusetts Institute of Technology, and IBM Almaden Research Center focuses on block copolymers a special class of polymers that under the proper conditions, will segregate on a microscopic scale into regularly spaced “domains” of different chemical composition.

The two groups demonstrated ways to observe and measure the shape and dimensions of the polymer rows in three dimensions. The experimental techniques can prove essential in verifying and tuning the computational models used to guide the fabrication process development.

It’s old news that the semiconductor industry is starting to run up against physical limits to the decades-long trend of ever-denser integrated chips with smaller and smaller feature sizes, but it hasn’t reached bottom yet.

Just recently, Intel Corp. announced that it had in production a new generation of chips with a 14-nanometer minimum feature size. That’s a little over five times the width of human DNA.

At those dimensions, the problem is creating the multiple masking layers, sort of tiny stencils, needed to define the microscopic patterns on the production wafer.

The optical lithography techniques used to create the masks in a process akin to old-school wet photography are simply not capable of reliably reproducing the extremely small, extremely dense patterns. There are tricks you can use such as creating multiple, overlapping masks, but they are very expensive.

Transmission electron microscope (TEM) tomography provides a nanoscale, 3D visualization of the structure of a templated block copolymer. The purple features are silica posts fabricated by electron-beam lithography that direct the self-assembly of the copolymer.

Hence the polymers. “The issue in semiconductor lithography is not really making small features—you can do that—but you can’t pack them close together,” explains NIST materials scientist Alexander Liddle. “Block copolymers take advantage of the fact that if I make small features relatively far apart, I can put the block copolymer on those guiding patterns and sort of fill in the small details.”

The strategy is called “density multiplication” and the technique, “directed self-assembly.”
Block copolymers (BCPs) are a class of materials made by connecting two or more different polymers that, as they anneal, will form predictable, repeating shapes and patterns.

With the proper lithographed template, the BCPs in question will form a thin film in a pattern of narrow, alternating stripes of the two polymer compositions.

Alternatively, they can be designed so one polymer forms a pattern of posts embedded in the other. Remove one polymer, and in theory, you have a near-perfect pattern for lines spaced 10 to 20 nanometers apart to become, perhaps, part of a transistor array.
If it works. “The biggest problem for the industry is the patterning has to be perfect. There can’t be any defects,” says NIST materials scientist Joseph Kline. “In both of our projects we’re trying to measure the full structure of the pattern.

Normally, it’s only easy to see the top surface, and what the industry is worried about is that they make a pattern, and it looks okay on the top, but down inside the film, it isn’t.”
Kline’s group, working with IBM, demonstrated a new measurement technique* that uses low-energy or “soft” X rays produced by the Advanced Light Source at Lawrence Berkeley National Labs to probe the structure of the BCP film from multiple angles.

Because the film has a regular, repeating structure, the scattering pattern can be interpreted, much as crystallographers do, to reveal the average shapes of the stripes in the film. If a poor match between the materials causes one set of stripes to broaden out at the base, for example, it will show up in the scattering pattern.

Their major innovation was to note that although the basic technique was developed using short-wavelength “hard” X rays that have difficulty distinguishing two closely related polymers, much better results can be obtained using longer wavelength X rays that are more sensitive to differences in the molecular structure.**

While X-ray scattering can measure average properties of the films, Liddle’s group, working with MIT, developed a method to look, in detail, at individual sections of a film by doing three-dimensional tomography with a transmission electron microscope (TEM).*** Unlike the scattering technique, the TEM tomography can actually image defects in the polymer structure—but only for a small area.

The technique can image an area about 500 nanometers across.

Between them, the two techniques can yield detailed data on the performance of a given BCP patterning system. The data, the researchers say, are most valuable for testing and refining computer models. “Our measurements are both fairly time-consuming, so they’re not something industry can use on the fab floor,” says Kline. “But as they’re developing the process, they can use our measurements to get the models right, then they can do a lot of simulations and let the computers figure it out.”

“It’s just so expensive and time-consuming to test out a new process,” agrees Liddle. “But if my model is well validated and I know the model is going to give me accurate results, then I can crank through the simulations quickly. That’s a huge factor in the electronics industry.”

*With the daunting name “resonant critical dimension small angle X-ray scattering” (res-CDSAXS).

**D.F. Sunday, M.R. Hammond, C. Wang, W. Wu, D. Delongchamp, M. Tjio, J. Cheng, J.W. Pitera, R.J. Kline.

Determination of the internal morphology of nanostructures patterned by directed self assembly. ACS Nano, 2014, 8 (8), pp 8426–8437 DOI: 10.1021/nn5029289.

***K.W. Gotrik, T. Lam, A.F. Hannon, W. Bai, Y. Ding, J. Winterstein, A. Alexander-Katz, J.A. Liddle, C.A. Ross. 3D TEM Tomography of templated bilayer films of block copolymers. Advanced Functional Materials. Article first published online Oct. 2, 2014 DOI: 10.1002/adfm.201402457.

Genesis Nanotech ‘News and Updates’ – September 9, 2014

Genesis Nanotech ‘News and Updates’ – September 9, 2014

Follow This Link: https://paper.li/GenesisNanoTech/1354215819#

Or by Individual Articles:

Transfer Printing Methods for Flexible Thin Film Solar Cells: Basic Concepts and Working Principles – ACS Nano (ACS Publications)

Nanotechnology to slash NOx and “cancerous” emissions

Tumor-Homing, Size-Tunable Clustered Nanoparticles for Anticancer Therapeutics – ACS Nano (ACS Publications)

New Detector Capable of Capturing Terahertz Waves at Room Temperature

Quotable Coach: Plug In And Participate – The Multiplier Mindset: Insights & Tips for Entrepreneurs

Genesis Nanotechnology – “Great Things from Small Things!”

10 Emerging Technologies That Will Change/ Have Changed (?) Your World

Note to Readers: It is interesting (To Us at GNT anyway) that the BOLD predictions for technology, should always be IOHO “re-visited”. What follows is the “Top 10 List” from 2004. 10 Years … How have the technology “fortune-tellers” done?!

 

 

10 Emerging Technologies That Will Change Your World

Technology Review unveils its annual selection of hot new technologies about to affect our lives in revolutionary ways-and profiles the innovators behind them.

Full Article Link Here: http://www2.technologyreview.com/featured-story/402435/10-emerging-technologies-that-will-change-your/

Technology Review: February 2004

With new technologies constantly being invented in universities and companies across the globe, guessing which ones will transform computing, medicine, communication, and our energy infrastructure is always a challenge. Nonetheless, Technology Review’s editors are willing to bet that the 10 emerging technologies highlighted in this special package will affect our lives and work in revolutionary ways-whether next year or next decade. For each, we’ve identified a researcher whose ideas and efforts both epitomize and reinvent his or her field. The following snapshots of the innovators and their work provide a glimpse of the future these evolving technologies may provide.

10 Emerging Technologies That Will Change Your World
Universal Translation
Synthetic Biology
Nanowires
T-Rays
Distributed Storage
RNAi Interference
Power Grid Control
Microfluidic Optical Fibers
Bayesian Machine Learning
Personal Genomics

Excerpt: Nanowires:

(Page 4 of 11)

PEIDONG YANG

Nanowires

Few emerging technologies have offered as much promise as nanotechnology, touted as the means of keeping the decades-long electronics shrinkfest in full sprint and transfiguring disciplines from power production to medical diagnostics. Companies from Samsung Electronics to Wilson Sporting Goods have invested in nanotech, and nearly every major university boasts a nanotechnology initiative. Red hot, even within this R&D frenzy, are the researchers learning to make the nanoscale wires that could be key elements in many working nanodevices.

“This effort is critical for the success of the whole [enterprise of] nanoscale science and technology,” says nanowire pioneer Peidong Yang of the University of California, Berkeley. Yang has made exceptional progress in fine-tuning the properties of nanowires. Compared to other nanostructures, “nanowires will be much more versatile, because we can achieve so many different properties just by varying the composition,” says Charles Lieber, a Harvard University chemist who has also been propelling nanowire development.

The World Of Tomorrow: Nanotechnology: Interview with PhD and Attorney D.M. Vernon

The Editor interviews Deborah M. Vernon, PhD, Partner in McCarter & English, LLP’s Boston office.

 

 

 

Why It Matters –

” … I would say the two most interesting areas in the last year or two have been in 3-D printing and nanotechnology. 3-D printing is an additive technology in which one is able to make a three-dimensional product, such as a screw, by adding material rather than using a traditional reduction process, like a CNC (milling) process or a grinding-away process.

The other interesting area has been nanotechnology. Nanotechnology is the science of materials and structures that have a dimension in the nanometer range (1-1,000 nm) – that is, on the atomic or molecular scale. A fascinating aspect of nanomaterials is that they can have vastly different material properties (e.g., chemical, electrical, mechanical properties) than their larger-scale counterparts. As a result, these materials can be used in applications where their larger-scale counterparts have traditionally not been utilized.”

Editor: Deborah, please tell us about the specific practice areas of intellectual property in which you participate.

 

 

Vernon: My practice has been directed to helping clients assess, build, maintain and enforce their intellectual property, especially in the technology areas of material science, analytical chemistry and mechanical engineering. Prior to entering the practice of law, I studied mechanical engineering as an undergraduate and I obtained a PhD in material science engineering, where I focused on creating composite materials with improved mechanical properties.

Editor: Please describe some of the new areas of biological and chemical research into which your practice takes you, such as nanotechnology, three-dimensional printing technology, and other areas.

Vernon: I would say the two most interesting areas in the last year or two have been in 3-D printing and nanotechnology. 3-D printing is an additive technology in which one is able to make a three-dimensional product, such as a screw, by adding material rather than using a traditional reduction process, like a CNC (milling) process or a grinding-away process. The other interesting area has been nanotechnology. Nanotechnology is the science of materials and structures that have a dimension in the nanometer range (1-1,000 nm) – that is, on the atomic or molecular scale.

A fascinating aspect of nanomaterials is that they can have vastly different material properties (e.g., chemical, electrical, mechanical properties) than their larger-scale counterparts. As a result, these materials can be used in applications where their larger-scale counterparts have traditionally not been utilized.

I was fortunate to work in the nanotech field in graduate school. During this time, I investigated and developed methods for forming ceramic composites, which maintain a nanoscale grain size even after sintering. Sintering is the process used to form fully dense ceramic materials. The problem with sintering is that it adds energy to a system, resulting in grain growth of the ceramic materials. In order to maintain the advantageous properties of the nanosized grains, I worked on methods that pinned the ceramic grain boundaries to reduce growth during sintering.

The methods I developed not only involved handling of nanosized ceramic particles, but also the deposition of nanofilms into a porous ceramic material to create nanocomposites. I have been able to apply this experience in my IP practice to assist clients in obtaining and assessing IP in the areas of nanolaminates and coatings, nanosized particles and nanostructures, such as carbon nanotubes, nano fluidic devices, which are very small devices which transport fluids, and 3D structures formed from nanomaterials, such as woven nanofibers.

Editor: I understand that some of the components of the new Boeing 787 are examples of nanotechnology.

Vernon: The design objective behind the 787 is that lighter, better-performing materials will reduce the weight of the aircraft, resulting in longer possible flight times and decreased operating costs. Boeing reports that approximately 50 percent of the materials in the 787 are composite materials, and that nanotechnology will play an important role in achieving and exceeding the design objective. (See, http://www.nasc.com/nanometa/Plenary%20Talk%20Chong.pdf).

While it is believed that nanocomposite materials are used in the fuselage of the 787, Boeing is investigating applying nanotechnology to reduce costs and increase performance not only in fuselage and aircraft structures, but also within energy, sensor and system controls of the aircraft.

Editor: What products have incorporated nanotechnology? What products are anticipated to incorporate its processes in the future?

Vernon: The products that people are the most familiar with are cosmetic products, such as hair products for thinning hair that deliver nutrients deep into the scalp, and sunscreen, which includes nanosized titanium dioxide and zinc oxide to eliminate the white, pasty look of sunscreens. Sports products, such as fishing rods and tennis rackets, have incorporated a composite of carbon fiber and silica nanoparticles to add strength. Nano products are used in paints and coatings to prevent algae and corrosion on the hulls of boats and to help reduce mold and kill bacteria. We’re seeing nanotechnology used in filters to separate chemicals and in water filtration.

The textile industry has also started to use nano coatings to repel water and make fabrics flame resistant. The medical imaging industry is starting to use nanoparticles to tag certain areas of the body, allowing for enhanced MRI imaging. Developing areas include drug delivery, disease detection and therapeutics for oncology. Obviously, those are definitely in the future, but it is the direction of scientific thinking.

Editor: What liabilities can product manufacturers incur who are incorporating nanotechnology into their products? What kinds of health and safety risks are incurred in their manufacture or consumption?

Vernon: There are three different areas that we should think about: the manufacturing process, consumer use and environmental issues. In manufacturing there are potential safety issues with respect to the incorporation or delivery of nanomaterials. For example, inhalation of nanoparticles can cause serious respiratory issues, and contact of some nanoparticles with the skin or eyes may result in irritation. In terms of consumer use, nanomaterials may have different material properties from their larger counterparts.

As a result, we are not quite sure how these materials will affect the human body insofar as they might have a higher toxicity level than in their larger counterparts. With respect to an environmental impact, waste or recycled products may lead to the release of nanoparticles into bodies of water or impact wildlife. The National Institute for Occupational Safety and Health has established the Nanotechnology Research Center to develop a strategic direction with respect to occupational safety and nanotechnology. Guidance and publications can be found at http://www.cdc.gov/niosh/topics/nanotech.

Editor: The European Union requires the labeling of foods containing nanomaterials. What has been the position of the Food & Drug Administration and the EPA in the United States about food labeling?

Vernon: So far the FDA has taken the position that just because nanomaterials are smaller, they are not materially different from their larger counterparts, and therefore there have been no labeling requirements on food products. The FDA believes that their current standards for safety assessment are robust and flexible enough to handle a variety of different materials. That being said, the FDA has issued some guidelines for the food and cosmetic industries, but there has not been any requirement for food labeling as of now. The EPA has a nanotechnology division, which is also studying nanomaterials and their impact, but I haven’t seen anything that specifically requires a special registration process for nanomaterials.

Editor: What new regulations regarding nanotech products are expected? Should governmental regulations be adopted to prevent nanoparticles in foods and cosmetics from causing toxicity?

Vernon: The FDA has not telegraphed that any new regulations will be put into place. The agency is currently in the data collection stage to make sure that these materials are being safely delivered to people using current FDA standards – that materials are safe for human consumption or contact with humans. We won’t really understand whether or not regulations will be coming into place until we see data coming out that indicates that there are issues that are directly associated with nanomaterials. Rather than expecting regulations, I would suggest that we examine the data regarding nano products to optimize safe handling and use procedures.

Editor: Have there ever been any cases involving toxicity resulting from nano products?

Vernon: There are current investigations about the toxicity of carbon nano tubes, but the research is in its infancy. There is no evidence to show any potential harm from this technology. Unlike asbestos or silica exposure, the science is not there yet to demonstrate any toxicity link. The general understanding is that it may take decades for any potential harm to manifest. I believe my colleague, Patrick J. Comerford, head of McCarter’s product liability team in Boston, summarizes the situation well by noting that “if any supportable science was available, plaintiff’s bar would have already made this a high-profile target.”

Editor: While some biotech cases have failed the test of patentability before the courts, such as the case of Mayo v. Prometheus, what standard has been set forth for a biotech process to pass the test for patentability?

Vernon: There is no specified bright-line test for determining if a biotech process is patentable. But what the U.S. Patent and Trademark Office has done is to issue some new examination guidelines with respect to the Mayo decision that help examiners figure out whether a biotech process is patent eligible. Specifically, the guidelines look to see if the biotech process (i.e., a process incorporating a law of nature) also includes at least one additional element or step. That additional element needs to be significant and not just a mental or correlation step. If a biotech process patent claim includes this significant additional step, there still needs to be a determination if the process is novel and non-obvious over the prior art. So while this might not be a bright-line test to help us figure out whether a biotech process is patentable, it at least gives us some direction about what the examiners are looking for in the patent claims.

Editor: What effect do you think the new America Invents Act will have in encouraging biotech companies to file early in the first stages of product development? Might that not run the risk that the courts could deny patentability as in the Ariad case where functional results of a process were described rather than the specific invention?

Vernon: The AIA goes into effect next month. What companies, especially biotech companies, need to do is file early. Companies need to submit applications supported by their research to include both a written description and enablement of the invention. Companies will need to be more focused on making sure that they are not only inventing in a timely manner but are also involving their patent counsel in planned and well-thought-out experiments to make sure that the supporting information is available in a timely fashion for patenting.

Editor: Have there been any recent cases relating to biotechnology or nanotechnology that our readers should be informed about?

Vernon: The Supreme Court will hear oral arguments in April in the Myriad case. This case involves the BRCA gene, the breast cancer gene – and the issue is whether isolating a portion of a gene is patentable. While I am not a biotechnologist, I think this case will also impact nanotechnology as a whole. Applying for a patent on a portion of a gene is not too far distant from applying for a patent on a nanoparticle of a material that already exists but which has different properties from the original, larger-counterpart material. Would this nanosize material be patentable? This will be an important case to see what guidance the Supreme Court delivers this coming term.

Editor: Is there anything else you’d like to add?

Vernon: I think the next couple of years for nanotech will be very interesting. As I mentioned, I did my PhD thesis in the nanotechnology area a few years ago. My studies, like those of many other students, were funded in part with government grants. There is a great deal of government money being poured into nanotechnology. In the next ten years we will start seeing more and more of this research being commercialized and adopted into our lives. To keep current of developments, readers can visit www.nano.gov.

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“At the Speed of Light” – New ‘Nanowires’ Support Integrated Nanophotonic Circuits

A new combination of materials can efficiently guide electricity and light along the same tiny wire, a finding that could be a step towards building computer chips capable of transporting digital information at the speed of light.

Abstract

The continually increasing demands for higher-speed and lower-operating-power devices have resulted in the continued impetus to shrink photonic components. We demonstrate a primitive nanophotonic integrated circuit element composed of a single silver nanowire and single-layer molybdenum disulfide (MoS2 ) flake.

Using scanning confocal fluorescence microscopy and spectroscopy, we find that nanowire plasmons can excite MoS2 photoluminescence and that MoS2 excitons can decay into nanowire plasmons. Finally, we show that the nanowire may serve the dual purpose of both exciting MoS2 photoluminescence via plasmons and recollecting the decaying exciton as nanowire plasmons. The potential for subwavelength light guiding and strong nanoscale light–matter interaction afforded by our device may facilitate compact and efficient on-chip optical processing.

© 2014 Optical Society of America

Funding By: Directorate for Mathematical and Physical Sciences (MPS)10.13039/100000086 (DMR-1309734); Office of Science, U.S. Department of Energy10.13039/100006132 (DE-FG02-05ER46207); NSF IGERT (DGE-0966089); Institute of Optics.

To read the Full Disclosure Paper Go Here:

http://www.opticsinfobase.org/optica/fulltext.cfm?uri=optica-1-3-149&id=300737

 

 

The Feynman Lectures on Physics now online

The lectures of Nobel Prize winning physicist Richard Feynman were legendary. They are most famously preserved in The Feynman Lectures. The three-volume set may be the most popular collection of physics books ever written, and now you can access it online, in its entirety, for free.

Caltech and The Feynman Lectures Website are presenting this online edition of The Feynman Lectures on Physics. Now, anyone with internet access and a web browser can enjoy reading a high quality up-to-date copy of Feynman’s legendary lectures.

Richard Feynman talking with a teaching assistant after the lecture on The Dependence of Amplitudes on Time, Robert Leighton and Matthew Sands in background, April 29, 1963. (© California Institute of Technology)

Volume 1 – mainly mechanics, radiation and heat

Volume 2 – mainly electromagnetism and matter

Volume 3 – quantum mechanics

Please note that this edition is only free to read online, and the posting on Caltech’s website does not transfer any right to download all or any portion of The Feynman Lectures on Physics for any purpose.

This edition has been designed for ease of reading on devices of any size or shape; text, figures and equations can all be zoomed without degradation.

Source: Caltech

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Sprinkling Spin Physics onto a Superconductor

JQI (Joint Quantum Institute)Fellow Jay Sau, in collaboration with physicists from Harvard and Yale, has been studying the effects of embedding magnetic spins onto the surface of a superconductor. They recently report in paper that was chosen as an “Editor’s Suggestion” in Physical Review Letters, that the spins can interact differently than previously thought. This hybrid platform could be useful for quantum simulations of complex spin systems, having the special feature that the interactions may be controllable, something quite unusual for most condensed matter systems.

The textbook quantum system known as a spin can be realized in different physical platforms. Due to advances in fabrication and imaging, magnetic impurities embedded onto a substrate have emerged as an exciting prospect for studying spin physics. Quantum ‘spin’ is related to a particle’s intrinsic angular momentum. What’s neat is that while the concept is fairly abstract, numerous effects in nature, such as magnetism, map onto mathematical spin models.

A single spin is useful, but most practical applications and studies of complex phenomena require controlling many interacting spins. By themselves, spins will interact with each other, with the interaction strength vanishing as spins are separated. In experiments, physicists will often use techniques, such as lasers and/or magnetic fields, to control and modify the interplay between spins. While possible in atomic systems, controlling interactions between quantum spins has not been straightforward or even possible in most solid state systems.

In principle, the best way to enhance communication between spins in materials is to use the moving electrons as intermediaries. Mobile electrons are easy to come by in conductors, but from a quantum physics perspective, these materials are dirty and noisy. Here, electrons flow around, scattering from the countless numbers of vibrating atoms, creating disruptions and masking quantum effects. One way physicists get around this obstacle is to place the spins on a superconducting substrate, which happens to be a quiet, pristine quantum environment.

Why are superconductors are a clean quantum host for spins? To answer this, consider the band structure of this system.

Band structure describes the behavior of electrons in solids. Inside isolated atoms, electrons possess only certain discrete energies separated by forbidden regions. In a solid, atoms are arranged in a repeating pattern, called a lattice. Due to the atoms’ close proximity, their accompanying electrons are effectively shared. The equivalent energy level diagram for the collective arrangement of atoms in a solid consists not of discrete levels, but of bunches or bands of levels representing nearly a continuum of energy values. In a solid, electrons normally occupy the lowest lying energy levels. In conducting solids the next higher energy level (above the highest filled level) is close enough in energy that transitions are allowed, facilitating flow of electrons in the form of a current.

Where do superconductors, in which electrical current flows freely without dissipation, fit into this energy level scheme? This effect is not the result of perfectly closing a gap–in fact the emergence of zero resistivity is a phase transition. As some materials are cooled the electrons can begin to interact, even over large distances, through vibrations in the crystal called phonons. This is called “Cooper pairing.” The pairs, though relatively weak, require some amount of energy to break, which translates into a gap in the band structure forming between the lowest energy superconducting state and the higher energy, non-superconducting states. In some sense, the superconducting state is a quantum environment that is isolated from the noise of the normal conducting state.

In this research, physicists consider what happens to the spin-spin interactions when the spins are embedded onto a superconductor. Generally, when the spins are separated by an amount greater than what’s called the coherence length, they are known to weakly interact antiferromagnetically (spin orientation alternating). It turns out that when the spins are closer together, their interactions are more complex than previously thought, and have the potential to be tunable. The research team corrects existing textbook theory that says that the spin-spin interactions oscillate between ferromagnetic (all spins having the same orientation) and antiferromagnetic. This type of interaction (called RKKY) is valid for regular conductors, but is not when the substrate is a superconductor.

What’s happening here is that, similar to semiconductors, the magnetic spin impurities are affecting the band structure. The spins induce what are called Shiba states, which are allowed electron energy levels in the superconducting gap. This means that there is a way for superconducting electron pairs to break-up and occupy higher, non-superconducting energy states. For this work, the key point is that when two closely-spaced spins are anti-aligned then their electron Shiba states mix together to strengthen their effective antiferromagnetic spin interaction. An exciting feature of this result is that the amount of mixing, and thus effective interaction strength, can be tuned by shifting around the relative energy of Shiba states within the gapped region. The team finds that when Shiba states are in the middle of the superconducting gap, the antiferromagnetic interaction between spins dominates.

Author and theorist Jay Sau explains the promise of this platform, “What this spin-superconductor system provides is the ability connect many quantum systems together with a definitive interaction. Here you can potentially put lots of impurity atoms in a small region of superconductor and they will all interact antiferromagnetically. This is the ideal situation for forming exotic spin states.”

Arrays of spins with controllable interactions are hard to come by in the laboratory and, when combined with the ability to image single spin impurities via scanning tunneling microscopy (STM), this hybrid platform may open new possibilities for studying complex interacting quantum phenomena.

From Sau’s perspective, “We are at the stage where our understanding of quantum many-body things is so bad that we don’t necessarily even want to target simulating a specific material. If we just start to get more examples of complicated quantum systems that we understand, then we have already made progress.”

Reference Publication

“Enhanced Antiferromagnetic Exchange between Magnetic Impurities in a Superconducting Host,” N.Y. Yao, L.I. Glazman, E.A. Demler, M.D. Lukin, J.D. Sau, Phys. Rev. Lett., 113, 087202 (2014)

– See more at: http://jqi.umd.edu/news/sprinkling-spin-physics-onto-superconductor#sthash.6SNA4foX.dpuf

Anti-Counterfeit Drug Labels (w/video): Only a ‘Breath’ Away

An outline of Marilyn Monroe’s iconic face appeared on the clear, plastic film when a researcher fogs it with her breath. Terry Shyu, a doctoral student in chemical engineering at the University of Michigan, was demonstrating a new high-tech label for fighting drug counterfeiting. While the researchers don’t envision movie stars on medicine bottles, but they used Monroe’s image to prove their concept.

Counterfeit drugs, which at best contain wrong doses and at worst are toxic, are thought to kill more than 700,000 people per year. While less than 1 percent of the U.S. pharmaceuticals market is believed to be counterfeit, it is a huge problem in the developing world where as much as a third of the available medicine is fake.

To fight back against these and other forms of counterfeiting, researchers at U-M and in South Korea have developed a way to make labels that change when you breathe on them, revealing a hidden image. This work is reported in Advanced Materials (“Shear-Resistant Scalable Nanopillar Arrays with LBL-Patterned Overt and Covert Images”). “One challenge in fighting counterfeiting is the need to stay ahead of the counterfeiters,” said Nicholas Kotov, the Joseph B. and Florence V. Cejka Professor of Chemical Engineering who led the Michigan effort.

 

 

The method requires access to sophisticated equipment that can create very tiny features, roughly 500 times smaller than the width of a human hair. But once the template is made, labels can be printed in large rolls at a cost of roughly one dollar per square inch. That’s cheap enough for companies to use in protecting the reputation of their products—and potentially the safety of their consumers.

Terry Shyu, MSE PhD Student, demonstrates use of nanopillars that reveal hidden images via condensation of fluid on the structures.   “We use a molding process,” Shyu said, noting that this inexpensive manufacturing technique is also used to make plastic cups.

The labels work because an array of tiny pillars on the top of a surface effectively hides images written on the material beneath. Shyu compares the texture of the pillars to a submicroscopic toothbrush. The hidden images appear when the pillars trap moisture.

“You can verify that you have the real product with just a breath of air,” Kotov said.

The simple phenomenon could make it easy for buyers to avoid being fooled by fake packaging.

Previously, it was impossible to make nanopillars through cheap molding processes because the pillars were made from materials that preferred adhering to the mold rather than whatever surface they were supposed to cover. To overcome this challenge, the team developed a special blend of polyurethane and an adhesive.

The liquid polymer filled the mold, but as it cured, the material shrunk slightly. This allowed the pillars to release easily. They are also strong enough to withstand rubbing, ensuring that the label would survive some wear, such as would occur during shipping. The usual material for making nanopillars is too brittle to survive handling well.

The team demonstrated the nanopillars could stick to plastics, fabric, paper and metal, and they anticipate that the arrays will also transfer easily to glass and leather.

Following seed funding from the National Science Foundation’s Innovation Corps program and DARPA’s Small Business Technology Transfer program, the university is pursuing patent protection for the intellectual property and is seeking commercialization partners to help bring the technology to market.

Source: University of Michigan