Listeria Death Toll Grows To 12 And More Cases Surface, With Ontario Being The Worst Hit Area - A possible answer

Monday August 25, 2008

CityNews.ca Staff

The death toll from the listeriosis outbreak is now at 12 - with six confirmed, and another 6 suspected - and the number of possible cases has topped 26, eleven of which are from Ontario.

The figures were confirmed Monday by Agriculture Minister Gerry Ritz and the Canadian Food Inspection Agency as the Maple Leaf Foods investigation continues.

It's not that anything has really changed since the previous numbers were released. It's more that officials have now widened the criteria they're using to count the victims, allowing for more possible deaths and more potential cases.

Ritz is warning those numbers are expected to climb as the incubation period continues to lengthen. It can take up to 70 days before symptoms show up in the most vulnerable.

"It is important to note that all the suspect cases have been diagnosed with listeriosis but it is only via laboratory testing, the generic fingerprint, that they determine if they are directly linked to this particular outbreak strain," Ritz explains. "We fully expect that both the numbers of suspected cases and confirmed cases will increase as this investigation continues and samples continue to be tested."

Why the big shift and dramatic increase in death assessments?

"It may seem like a huge jump," agrees CityNews Medical Specialist Dr. Karl Kabasele. "Going into the weekend, we were talking about 3 or 4 deaths. Now we're talking 12. The reason is a change in the definition of what constitutes a death related to this outbreak.

"Previously we were only talking about people for whom the coroner or another physician may have said the official cause of death was literiosis. Now that definition has been expanded and we're talking about anyone for whom listeriosis was a contributing factor to their death."

It means they may not have died directly from the bad bug but could have had it when they expired from something else.

All this comes as one of the largest product recalls in Canadian history continues, a call back that's costing the company at the centre of it millions of dollars.

Maple Leaf Foods has taken out huge ads apologizing for the crisis and is trying hard to make what amends it can.

"When listeria was discovered in the product, we launched immediate recalls to get it off the shelf. Then we shut the plant down. Tragically our products have been linked to illnesses and loss of life. To Canadians who are ill and for the family who have lost loved ones, I offer my deepest sympathies," Michael McCain, Maple Leaf Foods president, revealed in a televised statement. (See it here.)

There are now 220 products on the recall list after the Canadian Food Inspection Agency confirmed the company's plant near Sheppard Ave. and Highway 401 as the source of a recent outbreak of the bacteria listeria monocytogenes, which can cause the illness listeriosis.

Among the brands listed among the recalled items - Maple Leaf, Equity, Schneiders, and Shopsy's. They all have a key code of establishment 97B on them.

However, Shopsy's restaurants are not affected.

"Shopsy's Deli Restaurants is a different company than Maple Leaf Foods. We do share the trademark and they do package some foods under the Shopsy's brand but we do not serve those meats in our deli sandwiches at the restaurant," reiterated company president Gavin Quinn.

The North York plant was closed last week for disinfection, and if it passes strict tests it could reopen Tuesday.

"How it (listeria) got there or where exactly it is in that equipment, we may never know," admits Maple Leaf foods Linda Smith.

"That's why we instituted this much broader recall of 220 products, even though we don't have test results that say there might be listeria there. If there is a doubt, if there is a possibility, and we understand it's extensive in a long line of products and to consumers we apologize about that because we know many of them are checking products, and it's a process.

"We just want to do the right thing. And over time, consumers will make their own decisions."

The recall affected a number of restaurants as well, including McDonald's, Mr. Sub, Tim Hortons, and Boston Pizza. All have removed the meats from their menus.

The CFIA was first made aware of the problem on August 4. Federal Health Minister Tony Clement said the government response to the outbreak was appropriate, even though some complained it took too long from the time suspicions arose to the recall notice.

"The surveillance system picked up a problem that was occurring and allowed us to respond efficiently and effectively to an emerging public health issue," Clement said in a news conference Sunday.

Clement said it was tragic that four people died but noted "this is an example of where our surveillance system worked."

McCain estimated the recall would cost the company $20 million - ten times the original figure estimated when the list of recalled products was about two dozen. He said the decision to expand the recall was for safety reasons after the link was made between the listeriosis outbreak and the GTA plant.

"We felt, given the new information, we had to take the most conservative approach possible, and recalled 100 per cent of the production from the entire facility," McCain said.

"We have an unwavering commitment to keeping our food safe with the standards that go well beyond regulatory requirements," he added. "But this week, our best efforts failed and for that, we are deeply sorry."

That $20 million figure does not include the possible lawsuits that may follow from the families of those who got sick or perished from the outbreak.

Consumer confidence has definitely taken a hit.

"I'm cautious now when I'm shopping, for sure," said one Torontonian.

When CityNews asked another shopper if they would buy Maple Leaf products in the future, she quickly responded, "Probably not."

Maple Leaf has posted a full list of products affected on the company's website. To see it in a PDF version, click here.

There's also a list on the CFIA site - click here to see it.

Are you at risk for listeriosis?

How to minimize your risk

Maple Leaf Foods stock takes huge tumble on markets

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A possible non-radioactive sterilization remedy:

Large area electron source

	Publication number: US2004183032 Publication date: 2004-09-23 Inventor: FINK RICHARD LEE (US); THUESEN LEIF H (US) Applicant: NANO PROPRIETARY INC (US) Classification: - international: H01J33/00; H01J33/00; (IPC1-7): H01J33/00 - European: H01J33/00 Application number: US20040765533 20040127 Priority number(s): US20040765533 20040127; US20020262997 20021002; US20010326868P 20011003; US20010330358P 20011018 View INPADOC patent family View list of citing documents Also published as: US7078716 (B2) US6750461 (B2) US2003062488 (A1)
	Abstract of US2004183032 By using a large area cathode, an electron source can be made that can irradiate a large area more uniformly and more efficiently than currently available devices. The electron emitter can be a carbon film cold cathode, a microtip or some other emitter. It can be patterned. The cathode can be assembled with electrodes for scanning the electron source.

BACKGROUND INFORMATION
[0003] Electron beams can be used to sterilize medical instruments, food and packaging. Irradiation by electrons is an accepted medical treatment for certain skin cancers. Environmental uses are cleaning flue gasses and decontamination of medical waste. Industrial applications are drying of inks and polymer crosslinking.
.....
Referring to FIG. 8, there is illustrated a method for irradiating objects, such as mail 802, which may pass underneath the electron source 801 on a conveyor belt 803. The electron beams will pass through the envelope. Some energy may be lost at each surface of the letter killing or rendering harmless bacteria or virus species or toxic or other dangerous chemical compounds. Even though the figure shows an electron beam being applied from one side only onto the object, a plurality of e-beam soures can be utilized to arradiate the object 802 from different angles.

Source
USP 7,078,716
USP 6,750,461

So, perhaps Nano-Proprietary, now called Applied Nanotech Holdings, Inc. (APNT), has the answer. And no radioactivity (which disturbs consumers!) is involved.

Applied Nanotech contact details:

Email Contacts Dr. Zvi Yaniv President & CEO of Applied Nanotech, Inc. Dr. Richard Fink Vice President, R&D, Applied Nanotech, Inc. Doug Baker Investor Relations and Chief Financial Officer, Applied Nanotech Holdings, Inc. Investor Relations Contact Doug Baker 248.391.0612

Phn 512.339.5020 Fax 512.339.5021 Address 3006 Longhorn Blvd., Suite 107 Austin, TX 78758 Map/Driving Directions Source

Boise State research breakthrough may be 'magic bullet' for cancer treatment

Edition Date: 08/29/08

Boise State researchers have made a breakthrough in cancer treatment that may provide the “magic bullet” for the debilitating effects of chemotherapy.

The interdisciplinary group of researchers applied emerging nanotechnology techniques to traditional cancer research to come up with a highly effective method for the preferential killing of cancer cells while leaving ordinary cells healthy. This nanobiotechnology group is led by Boise State physics professor Alex Punnoose with strong contributions from biology professors Denise Wingett and Kevin Feris.

“One of the greatest challenges preventing advances in new therapeutic options for treating cancer is the inability of anticancer drugs to effectively differentiate between cancerous and normal healthy body cells,” said Wingett, a cancer researcher. “Many commonly used chemotherapeutic drugs target rapidly dividing cells but suffer from a relatively low therapeutic index, which is the ratio of toxic dose to effective dose.”

But the group discovered that zinc-oxide nanoparticles can preferentially kill cancer cells without impacting normal cells, a discovery that could potentially treat the cancer without the side effects caused by chemotherapy.

The group’s discovery is described in the paper “Preferential Killing of Cancer Cells and Activated Human T Cells Using ZnO Nanoparticles,” published in the July edition of the journal Nanotechnology. The paper has garnered significant attention in the scientific community, being downloaded more than 250 times in the first month of its publication, making it one of most popular articles in the 58 journals published by the Institute of Physics, the publisher of the journal Nanotechnology.

The article can be found online at: http://stacks.iop.org/0957-4484/19/295103.

“Until now, no group in the world has been able to produce inherent selective cancer-killing ability in nanoparticles,” Wingett said. “Current chemotherapy drugs typically consist of single molecules and do not provide much room for manipulation of the molecule. But nanoparticles can be modified so that certain characteristics, like cancer-killing attributes, can be accentuated. Because of this, we think there is room for improvement in what we have already demonstrated.”

Wingett said the selectivity of these nanomaterials may be enhanced by linking tumor-targeting proteins such as monoclonal antibodies, peptides, and small molecules to tumor-associated proteins, or by using nanoparticles for drug delivery. In addition to these future directions, the research team is exploring the possibility of altering the nanoparticles to further improve their inherent ability to kill cancer cells while sparing normal healthy body cells.

Cancer researchers across the country have taken notice of the work. Jame Abraham, the hematology/oncology section chief, director of the Comprehensive Breast Cancer Program and medical director at Mary Babb Randolph Cancer Center at West Virginia University, said that while more study is needed, the breakthrough has great promise.

“Oncology is always looking for a magic bullet, which can kill only the cancer cells, not killing the normal cells. This work is a major step toward that,” Abraham said. “I think this work will pave the way for more targeted therapies.”

The promise of the work has also helped the nanobiotech research group land a $503,000 National Science Foundation grant to acquire a fluorescent activated cell sorter that will give the research group greater ability to identify, analyze and sort nanoparticles.

In addition to enhancing this particular cancer research, the new equipment would support the research activity of at least 16 other Boise State researchers in the sciences, environmental health and engineering, as well as research being done at Northwest Nazarene University, the College of Idaho, the Boise Veterans Administration Medical Center, the Mountain States Tumor and Medical Research Institute and the local biotechnology industry.

Source

Beyond Nano Breakthrough, MIT Team Quietly Builds Virus-Based Batteries

August 28, 2008

(Photo Courtesy of Belcher Laboratory/MIT)

CAMBRIDGE, Mass. — In a surprise power development that could have implications for electronics, cars and even the military, researchers at MIT have created the world's first batteries constructed at the nano-scale by microscopic viruses.

A much buzzed-about paper published in the Proceedings of the National Academy of Sciences earlier this month details the team's success in creating two of the three parts of a working battery—the positively charged anode and the electrolyte. But team leader Angela Belcher told PM yesterday that the team has been working seriously on cathode technology for the past year, creating several complete prototypes.

"We haven't published those yet, actually. We're just getting ready to write them up and send them off," says Belcher, who won a MacArthur "genius" grant from the for her work in 2004, and a Breakthrough Award from PM in 2006. "The cathode material has been a little more difficult, but we have several different candidates, and we have made full, working batteries."

Instead of physically arranging the component parts, researchers genetically engineer viruses to attract individual molecules of materials they're interested in, like cobalt oxide, from a solution, autonomously forming wires 17,000 times thinner than a sheet of paper that pack themselves together to form electrodes smaller than a human cell.

"Once you do the genetic engineering with the viruses themselves, you pour in the solution and they grow the right combination of these materials on them," Belcher says.

The team is working on three main architectures: Film-like structures—as small as a human cell—could form a clear film to power lab-on-a-chip applications, laminate into smart-cards, or even interface with implanted medical devices. Mesh-like architectures—billions of tiny nano-components all interfaced together—might one day replace conventional batteries in larger applications like laptops and cars. And fiber-like configurations—spun from liquid crystal like a spider's silk—might one day be woven into textiles, providing a wearable power-source for the military. "We definitely don't have full batteries on those [fiber architectures]. We've only worked on single electrodes so far, but the idea is to try to make these fiber batteries that could be integrated into textiles and woven into lots of different shapes," Belcher says.

The M13 viruses used by the team can't reproduce by themselves, and are only capable of infecting bacteria. At just 880 nanometers long—500 times smaller than a grain of salt—the bugs allow researchers to work at room temperatures and pressures with molecular precision, using and wasting fewer hazardous materials. Now that they've demonstrated that the construction of such tiny electronic components is possible, the challenge facing researchers is how to make them practical.

"What we're working on is not thinking about a particular device application, but trying to improve the quality of the anode and cathode materials—using biology just to make a higher quality material for energy density," Belcher says. "We haven't ruled out cars. That's a lot of amplification. But right now the thing is trying to make the best material possible, and if we get a really great material, then we have to think about how do you scale it." — Chris Ladd

Source

GAS IONIZER

(WO/2008/103733) GAS IONIZER

• Biblio. Data
• Description
• Claims
• National Phase
• Notices
• Documents

Latest bibliographic data on file with the International Bureau Permanent Link Bookmark this page
Pub. No.: WO/2008/103733 International Application No.: PCT/US2008/054425 Publication Date: 28.08.2008 International Filing Date: 20.02.2008
IPC:	H01J 27/26 (2006.01), H01J 49/16 (2006.01)
Applicants:	APPLIED NANOTECH, INC. [US/US]; 3006 Longhorn Blvd., Suite 107, Austin, Texas 78758-7631 (US) (All Except US). SIONEX CORPORATION [US/US]; 8-A Preston Court, Bedford, Massachusetts 01730 (US) (All Except US). NAZAROV, Erkinjon, G. [US/US]; 58 Emerson Gardens, Lexington, Massachusetts 02420 (US). FINK, Richard, Lee [US/US]; 9306 Rolling Oaks Trail, Austin, TX 78750 (US) (US Only). KRYLOV, Evgeny [RU/US]; 158 Concord Road, Billerica, Massachusetts 01821 (US). MARKOSKI, Kenneth, A. [US/US]; 42 Vose Hill Road, Westford, Massachusetts 01886 (US). MILLER, Raanan, A. [US/US]; 27 Intervale Road, Chestnut Hill, Massachusetts 02467 (US).
Inventors:	NAZAROV, Erkinjon, G.; 58 Emerson Gardens, Lexington, Massachusetts 02420 (US). FINK, Richard, Lee; 9306 Rolling Oaks Trail, Austin, TX 78750 (US). KRYLOV, Evgeny; 158 Concord Road, Billerica, Massachusetts 01821 (US). MARKOSKI, Kenneth, A.; 42 Vose Hill Road, Westford, Massachusetts 01886 (US). MILLER, Raanan, A.; 27 Intervale Road, Chestnut Hill, Massachusetts 02467 (US).
Agent:	KORDZIK, Kelly, K.; Fish & Richardson P.C., P.O. Box 1022, Minneapolis, MN 55440-1022 (US).
Priority Data:	60/902,487 20.02.2007 US

Title:	GAS IONIZER
Abstract:	Field emission based ionization sources are provided, with the emitter (305) being a carbon nanotube field emitter. Such emitters can replace Ni-63 beta emitters. Ionization of a gas (308) that is flowed through the gap (310) between the emitter plates (301, 302) is performed by electron capture of the flow of electrons by the molecules in the gas (308).

WHAT IS CLAIMED IS:

1. A method for ionizing a gas comprising: flowing a gas between first and second conductors, the first conductor further comprising a first coating containing nano-structures; and applying a voltage potential between the first and second conductors causing molecules in the gas to form ions, wherein electrons flowing between the molecules and the first conductor are emitted from or captured by the nano-structures.

Source

LUBRICANT ENHANCED NANOCOMPOSITES

United States Patent Application	20080206559
Kind Code	A1
LI; YUNJUN ; et al.	August 28, 2008

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LUBRICANT ENHANCED NANOCOMPOSITES

Abstract

Strings configured for use in sports racquets and musical instruments are fabricated as a plastic core wrapped with one or more filaments of plastic. The strings are coated with a material composite that includes rigid nanoparticles, and lubricated nylon. The rigid nanoparticles may include clay or carbon nanotubes. The strings are coated with the material composite using various processes that result in a coating thickness of between 0.1 and 200 .mu.m. The material composite may further include impact modifiers. The strings experience extended life due to reduced frictional wear and improved mechanical properties.

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Inventors:	LI; YUNJUN; (Austin, TX) ; Yaniv; Zvi; (Austin, TX) ; Mao; Dongsheng; (Austin, TX)
Correspondence Name and Address:	FISH & RICHARDSON P.C. P.O BOX 1022 Minneapolis MN 55440-1022 US
Serial No.:	036438
Series Code:	12
Filed:	February 25, 2008

U.S. Current Class:	428/368; 473/543; 524/445; 524/495; 524/612
U.S. Class at Publication:	428/368; 524/612; 524/445; 524/495; 473/543
Intern'l Class:	C08K 3/34 20060101 C08K003/34; C08K 3/04 20060101 C08K003/04; A63B 49/00 20060101 A63B049/00

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Claims

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1. A material composite comprising rigid nanoparticles, and lubricated nylon.

2. The composite of claim 1, wherein the rigid nanoparticles comprise carbon nanotubes or clay particles.

3. The composite of claim 1, wherein the lubricated nylon may comprise graphite, molybdenum disulfide, Silicone, Teflon.RTM., and titanium dioxide.

4. The composite of claim 1, further comprising impact modifiers selected from a set of impact modifiers including styrene-ethylene/butylene-styrene (SEBS), maleic anhydride grafted ethylene and propylene copolymer, a plasticizer, a compatiblizer, and combinations therein.

Source

Low Work Function Material

United States Patent Application	20080206448
Kind Code	A1
Mao; Dongsheng ; et al.	August 28, 2008

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Low Work Function Material

Abstract

The present invention is directed toward methods for incorporating low work function metals and salts of such metals into carbon nanotubes for use as field emitting materials. The present invention is also directed toward field emission devices, and associated components, comprising treated carbon nanotubes that have, incorporated into them, low work function metals and/or metal salts, and methods for making same. The treatments of the carbon nanotubes with the low work function metals and/or metal salts serve to improve their field emission properties relative to untreated carbon nanotubes when employed as a cathode material in field emission devices.

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Inventors:	Mao; Dongsheng; (Austin, TX) ; Yaniv; Zvi; (Austin, TX) ; Fink; Richard Lee; (Austin, TX) ; Pavlovsky; Igor; (Austin, TX)
Correspondence Name and Address:	FISH & RICHARDSON P.C. P.O BOX 1022 Minneapolis MN 55440-1022 US
Assignee Name and Adress:	Nano-Proprietary, Inc.
Serial No.:	028171
Series Code:	12
Filed:	February 8, 2008

U.S. Current Class:	427/77; 427/443.2; 977/742; 977/750; 977/752; 977/847
U.S. Class at Publication:	427/77; 427/443.2; 977/742; 977/750; 977/752; 977/847
Intern'l Class:	B05D 5/12 20060101 B05D005/12

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Claims

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1. A method comprising the steps of :a) dispersing carbon nanotubes in a metal salt solution comprising a solvent; and b) removing the solvent to yield metal salt-treated carbon nanotubes.

[0079]It can be seen from FIG. 12 that the Cs salt-treated CNTs have significantly better field emission properties than untreated CNTs. A threshold field of less than 0.9 V/.mu.m and emission current of 30 mA at 1.84 V/.mu.m was achieved for the Cs salt-treated CNTs, whereas the untreated CNTs exhibited a threshold field of about 1.3 V/.mu.m and required a field of approximately 2.80 V/.mu.m to generate an emission current of 30 mA.


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Advances in nanomedicine - understanding the intricacies of nanoparticle drug delivery

Posted: August 28, 2008

(Nanowerk Spotlight) Nanomedicine, especially drug delivery with nano-sized drug carriers, is all the rage these days. The concept sounds simple: make nanoscale containers that can escape detection by the body's defense mechanisms, fill them with a drug, get them to the desired location within the body, release the drug payload and, presto, you've got a very effective and efficient weapon for instance to fight cancer. That this model works in principle has already been demonstrated in numerous studies. The same studies show the complicated nature and the many difficulties that scientists are facing in fabricating the right nanocontainers, getting them to the right location, controlling the release mechanism of the drug, measuring the drugs' efficacy, and monitoring the now empty delivery vehicles' fate.

In a previous Spotlight – Mathematical engines of nanomedicine – we described the vast complexities in designing effective nanoparticles that take into account a wide range of possible design parameters (such as size, shape, surface properties, bulk properties, surface density of targeting moieties) and the biological characteristics of the cellular target in the body (such as receptor density, blood-flow descriptors, wall permeability). The findings we described in this article also indicate that almost all the nanocarriers that are in the clinic or in the preclinical pipeline today are basically the worst possible size and shape for their intended purpose.

That engineered nanomaterials, especially inorganic ones, will be used for nanomedicine applications has now become a certainty. However, the use of these nanomaterials should occur with detailed knowledge of delivery, fate and functioning at the target, and finally release from the body. And that's an area where a lot of unanswered questions remain.

In particular, the question of what happens if (and that still often is a big if) the drug-containing nanoparticles reach their intended target is a crucial one: How do the drug molecules get released from the delivery vehicle? In other words, how does the 'envelope' get opened? What is the fate of the nanoparticles (drugs as well as containers) post opening? New work done by scientists in India is contributing to how the nanoscience community is tackling these issues.

Researchers from the Indian Institute of Technology Guwahati present experimental results which suggest that the specificity of release of encapsulated nanoparticles could be achieved with an appropriate combination of encapsulating materials and the choice of an appropriate enzyme that would cleave the encapsulation to release the nanoparticles.

"We have shown that the release of nanoparticles encapsulated in biofriendly starch by specific enzymes can serve as a prototype model for studying the digestion of biofunctionalized nanoparticles and may open newer research avenues where the stabilization and release of nanoparticles could be achieved using well-known therapeutic biomolecules," Dr. Arun Chattopadhyay tells Nanowerk.

Schematic representation of the proposed mechanism of gold nanoparticle transfer from the starch-gold nanoparticle composite to the enzyme. The 3D structure of α-amylase is retrieved from Protein Data Base (PDB) entry 1DHK. (Reprinted with permission from American Chemical Society)

Chattopadhyay, a professor in the Department of Chemistry at the Indian Institute of Technology Guwahati, together with his colleagues, has published his findings in the August 20, 2008 online edition of Langmuir ("Probing Au Nanoparticle Uptake by Enzyme Following the Digestion of a Starch-Au-Nanoparticle Composite").

In this paper, the IIT team reports the results of studies on the enzymatic release of gold nanoparticles encapsulated in starch.

"In particular, we observed that the digestion of a gold nanoparticles-starch composite by α-amylase not only led to the degradation of starch into its lower analogues but also resulted in the release of encapsulated gold nanoparticles and their subsequent uptake by the enzyme" Chattopadhyay explains. "In addition to conventional biochemical and microscopy probes, the surface plasmon resonance (SPR) of gold nanoparticles provided a convenient way of following the reaction and establishing the mechanism. Our observations indicated that the rate of digestion of the starch-gold nanoparticles composite by alpha amylase was similar to that of pure starch and the free thiol groups of the enzyme possibly facilitated the uptake of gold nanoparticles by the enzyme in comparison to other carbohydrate-degrading enzymes such as amyloglucosidase."

These results could be particularly useful for nanoscale drug delivery and imaging studies in vitro. For example, if one wants to screen microorganisms that produce alpha amylase this method would allow a quick and easy way of doing that: the test of the presence of alpha amylase (produced by microorganisms) could be done by the starch-gold nanoparticle composite, which subsequently would release the nanoparticles (catalyzed by the enzyme). Of course, details of the concentrations of the composite etc. would still need to be worked out.

Chattopadhyay gives another example: "If one is interested in screening alpha amylase inhibitors then similar method could be used for that purpose. Alpha amylase inhibitors are known in plants to play important roles in rendering pest resistance attributes to the plants. Hence, there is a tremendous interest in developing transgenic plants bearing such inhibitors. The screening of the inhibitors produced by the plant (or the functional assay of the inhibitors) could be done based on the present method., i.e. measuring the change in localized SPR of gold nanoparticles."

The IIT scientists are currently working on two major areas in the nanomedicine field – fundamental understanding of phenomena related to the development of nanomaterial based diagnostics and therapeutics.

"While conventional diagnostics take either a long time to complete, may involve cumbersome steps, are too expensive to be affordable for a large section of the population, or exhibit low efficiency or sensitivity, the use of nanomaterials could be of great help in overcoming those disadvantages" says Chattopadhyay. "The question is: can one address these downsides systematically, with a reasonably good understanding of the science part of the process? We would like to do that systematically at least in some of the cases."

He mentions that he and his IIT colleagues are also working on the development of nanomaterials-based therapeutics. "For example, we have recently shown that use of silver nanoparticles in conjunction with gene therapy may be a better option for anti-cancer therapy than the use of either of them ("Implications of silver nanoparticle induced cell apoptosis for in vitro gene therapy"). We are currently working on the use of composites rather that use of nanoparticles alone for similar purposes. That way the use of each component (of the composite) would be minimized, while the efficiency of the composite would be better than the isolated components at lower concentrations."

By Michael Berger. Copyright 2008 Nanowerk LLC

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Nanoparticles Stick a Perfect Landing

Previous Story / Volume 22 archive Phys. Rev. B 78, 081405 (issue of August 2008) Title and Authors 27 August 2008 T. Dumitrică/Univ. of Minnesota On the rebound. A nanoparticle containing some 30,000 silicon atoms and moving at 900 meters per second will bounce off a surface (left sequence), but at 2,000 meters per second, it sticks (right sequence), according to computer simulations. The higher-speed impact causes two sequential changes in the crystalline structure. A silicon nanoparticle flying at 8 times the speed of sound can slam into a surface and stick, but it bounces off if colliding at half that speed. This puzzling observation is now explained by computer simulations reported in the August Physical Review B. The pressure of impact causes the higher speed particle to change its crystalline structure, which soaks up so much energy that the particle can't bounce away. These results may help researchers who are developing wear-resistant coatings that are created by many such high-speed impacts. Steven Girshick and his team at the University of Minnesota in Minneapolis are designing super-hard, wear-resistant coatings for machine tools. In their patented technique, a spray of particles--each a few nanometers across and containing silicon or some combination of chemicals--strikes a target substrate, such as a silicon surface, with velocities between 1 and 2 kilometers per second. The lumpy coating is built up as these nanoparticles stick to the surface. This technique can create similar rough-textured coatings that are being developed for other purposes, such as for sensors and catalysts. Girshick's team uses high-speed nanoparticles because they stick without splattering, unlike lower-speed particles, but the team never understood why the higher speed helps. Sticking implies that the kinetic energy is changed into another form, or "dissipated." If these were macroscopic objects--like sticky BBs shot into a wall--the energy would dissipate through buckling or crumpling in the crystalline structure. "But at the nanoscale, there is not enough space or time to create these dislocations," says Traian Dumitrică, also at the University of Minnesota. To investigate where the energy goes, Dumitrică and graduate student Mayur Suri ran computer simulations of a hypersonic nanoparticle. They began with a sphere of 30,000 silicon atoms arranged in a diamond-like crystalline structure in which each atom bonds to four neighbors. They then simulated this nanoparticle smashing into a silicon surface. They found that for speeds less than 1.2 kilometers per second, the nanoparticle bounces off the surface like a basketball. But at higher speeds, some of the nanoparticle undergoes a phase transition to a compressed state called β-tin, where each atom bonds to six neighbors. This transition is surprising, Dumitrică says, because the collision energy is not high enough to induce a phase transition in a macroscopic object. However, the impact force is applied over a few square nanometers, so the pressure inside the nanoparticle is extremely large--around 200,000 atmospheres, which is more than enough to cause the phase transition. The β-tin state only lasts a few picoseconds, though. As the nanoparticle begins to bounce back, there is a second phase transition to an amorphous, or disordered, state. The combination of the two phase transitions, plus some heat generation, takes up all of the kinetic energy, and the particle remains on the surface. After all of this action, "the recoil is too weak to beat the adhesion forces between the nanoparticle and the substrate," Dumitrică says. Girshick says this work provides new insight into what makes a nanoparticle stick or bounce. This information could help engineers tune the speeds to increase the adhesion of a nanostructured film to a substrate. "Adhesion is a very important property, especially if you are using the film in an aggressive environment like industrial machining," he says. --Michael Schirber Michael Schirber is a freelance science writer in Lyon, France. Efficient Sticking of Surface Passivated Si Nanospheres Via Phase Transition Plasticity M. Suri and T. Dumitrică Phys. Rev. B 78, 081405 (issue of August 2008)

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University of Oklahoma Researchers Developing New Tool to Detect Cancer

8/27/2008 1:00:59 PM

Early cancer detection can significantly improve survival rates. Current diagnostic tests often fail to detect cancer in the earliest stages and at the same time expose a patient to the harmful effects of radiation. Led by Dr. Patrick McCann, a small group of internationally known researchers at the University of Oklahoma with expertise in the development of mid-infrared lasers is working to create a sensor to detect biomarker gases exhaled in the breath of a person with cancer.

Proof-of-concept detection of a suspected lung cancer biomarker in exhaled breath has already been established as reported by the Oklahoma group in the July 2007 issue of Applied Optics. The research was inspired by studies showing that dogs can detect cancer by sniffing the exhaled breath of cancer patients. For example, by smelling breath samples, dogs identified breast and lung cancer patients with accuracies of 88 and 97 percent, respectively, as reported in the March 2006 issue of Integrative Cancer Therapies. The evidence is clear—gas phase molecules are uniquely associated with cancer.

Intrigued by the concept of using breath analysis to detect cancer, McCann saw an opportunity to use mid-infrared laser technology to help elucidate the relationship between specific gas phase biomarker molecules and cancer. He believes it is possible to develop easy-to-use detection devices for cancer, particularly for hard-to-detect cancers like lung cancer. McCann says we need sensors that detect these gas phase cancer biomarkers. “A device that measures cancer specific gases in exhaled breath would change medical research, as we know it.”

McCann says the science and technology exist to support the development of a new tool to detect cancer, but the research will take from five to 10 years to get low-cost devices into the clinic. OU may have the strongest contingent of researchers dedicated to providing a solution to the problem using this approach. Even though studies confirm that dogs can detect cancer by smelling the gases, they can’t tell us what gases they smell. It’s up to the medical research community using the best measurement tools to figure that out.

According to McCann, “Improved methods to detect molecules have been demonstrated, and more people need to be using these methods to detect molecules given off from cancer. We have developed laser-based methods to detect molecules. Mid-infrared lasers can measure suspected cancer biomarkers—ethane, formaldehyde and acetaldehyde.” McCann will use nanotechnology to improve laser performance and shrink laser systems, which would allow battery-powered operation of a handheld sensor device.

“You often have to go outside your discipline to pioneer new areas of research and Oklahoma has an advantage with so many experts in other fields. But getting funding for interdisciplinary research is challenging. However, more capital and research infrastructure are needed for this device to become a reality. As we build upon our existing capabilities Oklahoma can become more widely known as a center of excellence in this important area.”

Even though McCann is not a cancer researcher, he wants his research on developing innovative laser technology to benefit the millions of people who would otherwise suffer from a late-stage cancer diagnosis. McCann knows it can be done. He says, “The science supports it, and the dogs tell us there is something there.”

Source

CNT-TFTs, flexible displays, ANI, University of Stuttgart

Alternative Displays

August 26, 2008

Single-wall carbon nanotube (CNT) thin-film transistors (TFTs) are now possible for flexible displays and electronics, thanks to breakthroughs from the collaboration between the University of Stuttgart, Germany, and Applied Nanotech, Inc (ANI). Dr Paul Beatty an expert in the displays industry now follows up with some additional details and insights.

The team announced June 26 it had obtained improved yield from its proprietary printing method, which avoids expensive photolithography. Furthermore, high mobility (100 cm2/Vs) and high on/off ratio (105) were achieved, which is far better than printed TFTs using organic semiconductors.

Such high mobility means these TFTs can be made small enough to avoid obscuring too much light, and therefore do not need to be transparent or hidden on the other side of substrates or display layers. The on/off ratio compares with a value of under 10 for previous attempts at the University of Maryland in 2005, in which printing of CNTs also was used.

No details were given of the precise yield, pending more data, or the particular printing method used, but ANI said ink-jet and microcontact printing methods may work. Dr. Zvi Yaniv, president and CEO of ANI, said yield is likely to be more a function of CNT purity, particularly semiconducting versus metallic types. Improvements in preparing purer CNTs has enabled monolayer CNTs to form the TFT semiconducting channels, which avoids the tremendous variations in mobility and threshold voltages found earlier. ANI considers the additional costs of higher purity to be inconsequential because so little of the material is needed in a display.

In the past, the significant proportion of metallic rather than semiconducting CNTs led to lower on/off ratios, and this can short-circuit the transistor. In fact, a previously reported method of removing the metallic type was by attacking with nitronium ions (NO2+) in a mixture of nitric and sulfuric acids (e.g. Cheol-Min Yang at Sungkyunkwan University, Republic of Korea, J. Phys. Chem. B, 2005, 109). ANI has its own methods, but also buys CNTs from other suppliers, and some of the latest separation methods are said to be more commercially viable and also allow selection of CNTs having the same "chirality."

Dr.Yaniv said, "Chirality relates to the skew of the rolled-up graphitic sheet of carbon atoms. This determines the semiconducting energy band gap affecting the mobility and threshold voltage." So, having CNTs with all the same chirality allows a smaller variation in the mobility and threshold voltage.

Of particular interest for flexible displays, electronic circuits and sensors is the ability to deposit at low temperature compatible with flexible plastic substrates. For more information about ANI's thin-film transistor approach see Solution-deposited carbon nanotube layers for flexible display applications, published in Physica E 37, Issue 1-2 (March 2007). There, researchers obtained a mobility of 1cm2/Vs, but not yet the homogeneity and reproducibility that has been addressed in this latest work.

Interestingly, Dr.Yaniv agreed that any adsorbent from the atmosphere on the CNTs can change the TFT characteristics, and that encapsulation by passivation will be necessary. But he said effects of gas and water vapor on the gate part of the TFT is less severe than for TFTs made with a-Si. (See also plastic vs. metal foil substrates as mentioned in the FlexTech Alliance contract searching for other metal foils besides stainless steel.) Overall, Dr. Yaniv did not see a problem with lifetime for these CNTs.

"The collaboration with the University of Stuttgart is very productive," he said. "Their expertise and facilities for microelectronic processes are well known and are very suitable for our need to transition from an idea to a proof of concept." The university's emphasis was on the deposition of CNTs in flexible displays, while ANI concentrated on the CNT material.

Dr. Yaniv maintains that there will be no problem going up in substrate size for larger displays or lower-cost volume production as the equivalent to large mother glass. Compared to organic TFTs, the numbers of addressed pixels should be greater, although any need for very short channel lengths may limit conductivity as the "percolation" mechanism for the fishnet monolayer of CNTs may not work. Ultimately, this might limit the pixel density, but the specific number has yet to be determined, and depends also on the final levels of the metallic CNT impurities. Furthermore, it appears the CNT-TFTs are compatible with the electrical requirements of all the applicable flexible display technologies, although the initial development work is with LCDs.

An attribute for use in displays is the transparency of electrodes. In related work on use of transparent CNTs as replacement for the usual thin-film transparent indium tin oxide (ITO) pixel electrodes, Prof. Dr. Ing Norbert Fruehauf at the University of Stuttgart presented a paper in May at SID '08 revealing a working demonstration of a 4-inch diagonal 320 x RGB x 240 a-Si TFT-LCD made in this way. Prepared entirely at the university's facilities, CNTs were deposited by a low-cost spray method. Sheet resistance for electrodes does not need to be so low, but high transmittance is more important. The researchers found purified CNTs prepared by the HiPCO process gave a transmittance up to about 94% for a sheet resistance of 2,000 to 3,000 Ohms/square. Using conventional a-Si TFTs with such electrodes resulted in an on/off ratio of 106 and mobility of 0.4 -0.6 cm2/Vs.

APNT is a holding company with wholly owned operating subsidiaries Applied Nanotech and Electronic Billboard Technology Inc. (EBT). ANI's business model is to license its technology to partners that will manufacture and distribute products using the technology. Dr. Yaniv said, "Ideally for us would be to find a strategic partner that would want to take this to a pilot line."nTogether, the companies have more than 250 patents or patents pending, with at least one on this development, and one held by the University of Stuttgart.

by Dr Paul Beatty

Source

IBM demonstrates light-emitting nanotube

R. Colin Johnson
EE Times
(08/25/2008 8:42 AM EDT)

PORTLAND, Ore. — Electric control of the spectrum, direction and efficiency of light-emitting nanotubes (LENs) has been demonstrated by researchers at IBM Corp.'s Thomas J. Watson Research Center, bringing silicon photonics one step closer to reality.

IBM Research (Yorktown Heights, N.Y.) previously demonstrated record-breaking silicon optical waveguides and higher electroluminescent efficiency for LENs compared to LEDs. Now, it has put a LEN inside an optical waveguide to achieve directional surface emission, wavelength selectivity and the potential for ultrahigh efficiency.

"Like most light-emission sources, nanotubes emit light in all directions. Their spectrum was relatively broad and their efficiency was not very high," said Phaedon Avouris, IBM Fellow and manager of Nanometer Scale Science and Technology at IBM Research. "We attacked all these problems, making its light directional so it can be coupled to optical filters or to a device to transport it. We controlled its spectrum with an optical cavity and we have proposed a theory to help us achieve higher efficiency."

By fabricating an optical cavity around light-emitting nanotube mirrors at the bottom and top, wavelengths were confined to the desired 1.55-micron communications frequency.

IBM achieved surface emission by combining a single nanotube-based field-effect-transistor with a pair of metallic mirrors, one above and below the nanotube which lies flat on the silicon chip. The bottom mirror was made from silver, with a top half-mirror made from gold. Light was emitted from the nanotube in the cavity, which was filled with transparent dielectric.

The distance between the top and bottom mirrors was calculated to be half of the desired emission wavelength, which was set to be near a communications wavelength of 1.55 microns. Light was reflected upward off the bottom of the cavity, where half was passed as a surface emission from the LEN while the other half was reflected back down to the bottom mirror to reinforce the desired emission wavelength.

"We confined the emission in an optical cavity with two mirrors, so that light forms a standing wave between the mirrors which enhanced the frequencies, whose wavelength were equal to half the size of the cavity," said Avouris. "We used lithography to form the cavities, which achieved a dramatic enhancement--confining the spectrum to about 10 percent of what it was without the cavity, and giving us an overall enhancement [in the efficiency] of the emission of 400 percent."

Nanotubes have slightly different diameters (in this case, about 2 nanometers). As a result, they have slightly different bandgaps, and thus emit light at slightly different frequencies. However, by integrating the nanotube inside a cavity, physical confinement in the structure "eliminates unwanted frequencies thus [solving] the problem of nanotubes having slightly different diameters," according to Avouris.

IBM has demonstrated two methods of light emission in nanotubes: one that injects hot carriers into each end and another in which one end gets electrons while the other end gets holes. Another method injects excitons into one end. By characterizing these two methods, IBM claims to have finally answered the question of how electroluminescence compares to photoluminescence.

"There has always been a controversy over whether electroluminescence and photoluminescence involve the same states, so through comparisons using Raman scattering we have now proven that they both use the same states," said Avouris.

IBM has also proposed a theory for how heat diverts energy from luminescence, thus reducing the efficiency of LENs. While further experimentation will be required to prove the theory, IBM claims it is now only a matter of time until virtually all wasted energy that formerly generated heat can be eliminated by changing the electronic structure of a device.

"There are two types of emission from an object, radiative and nonradiative, with the latter being the energies lost by heat," said Avouris. Radiative emission "was always thought to be a fixed property of the material, but what we realized was that it is not only the material that is quantized--that has discrete states--but the photons also are part of a field that has quantized states.

"Emission comes by coupling these two fields. We now feel that by using an electric field we can change the electronic structure of nanotubes so that heat cannot be generated," he added.

Besides improving the efficiency of future devices by eliminating heat generation, IBM researchers also plan to experiment with methods of aligning nanotubes to a superlattice. This would allow an array of LENs to be fabricated on future silicon photonic chips.

Source

Nano-particles to ensure better absorption of antioxidants

August 26th, 2008 - 3:53 pmWashington, Aug 26 (IANS)

Researchers have designed a nano-sized “trojan horse” particle to ensure better absorption of healing antioxidants by the body. Antioxidants are known to neutralise the harmful effect of free radicals and other reactive chemical species that are constantly generated by our body and are thought to promote better health.

Fruits like papaya, guava and vegetables like tomatoes (lycopene) are natural sources of antioxidants.

Ken Ng and Ian Larson of Monash University’s have designed a nanoparticle, one thousandth the thickness of a hair, that protects antioxidants from being destroyed in the gut and ensures a better chance of them being absorbed in the digestive tract.

Normally the body’s own antioxidant defence is sufficient, but in high-risk individuals, such as those with a poor diet or those at risk of developing atherosclerosis, diabetes or Alzheimer’s disease, a nutritional source of antioxidants is required.

Larson said orally delivered antioxidants were easily destroyed by acids and enzymes in the human body, with only a small percentage of what is consumed actually being absorbed.

The solution is to design a tiny sponge-like chitosan biopolymeric nanoparticle as a protective vehicle for antioxidants. Chitosan is a natural substance found in crab shells.

“Antioxidants sit within this tiny trojan horse, protecting it from attack from digestive juices in the stomach,” Larson said.

“Once in the small intestine the nanoparticle gets sticky and bonds to the intestinal wall. It then leaks its contents directly into the intestinal cells, which allows them to be absorbed directly into the blood stream.

“We hope that by mastering this technique, drugs and supplements also vulnerable to the digestive process can be better absorbed by the human body,” said Larson.

The research project will proceed to trials early in 2009.

Source

Buckysomes: Fullerene-Based Nanocarriers for Hydrophobic Molecule Delivery

Ranga Partha, Linsey R. Mitchell, Jennifer L. Lyon, Pratixa P. Joshi, and Jodie L. Conyers*

Department of Internal Medicine, The University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, Texas 77030

^*Address correspondence to Jodie.L.Conyers@uth.tmc.edu.

ABSTRACT

We report the preparation and preliminary in vitro studies of nanocarriers termed “buckysomes,” which are self-assembled, spherical nanostructures composed of the amphiphilic fullerene AF-1. By inducing AF-1 self-assembly at an elevated temperature of 70 °C, dense spherical buckysomes with diameters of 100−200 nm were formed, as observed by electron microscopy and dynamic light scattering. The amphiphilic nature of AF-1 results in the formation of many hydrophobic regions within the buckysomes, making them ideal for embedding hydrophobic molecules to be tested in a drug delivery scheme. After confirming the cellular internalization of buckysomes embedded with the hydrophobic fluorescent dye 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate, we embedded paclitaxel, a highly hydrophobic anticancer drug. The in vitro therapeutic efficacy of the paclitaxel-embedded buckysomes toward suppression of MCF-7 breast cancer cell growth was compared to that of Abraxane, a commercially available, nanoparticle-albumin-bound formulation of paclitaxel. Notably, the paclitaxel-embedded buckysomes demonstrated a similar efficacy to that observed with Abraxane in cell viability studies; these results were confirmed microscopically. Moreover, negative control studies of MCF-7 viability using empty buckysomes demonstrated that the buckysomes were not cytotoxic. The results of our studies suggest that buckysomes prepared from self-assembly of AF-1 at 70 °C are promising nanomaterials for the delivery of hydrophobic molecules.

Source

Background:

Self assembly of amphiphilic C₆₀ fullerene derivatives into nanoscale supramolecular structures

Full Text

Smelling Skin Cancer

by Sunita Reed | August 20th, 2008

Research announced today confirms that skin with cancer gives off a different odor than normal skin. This ScienCentral News video reports on the first odor profile for skin cancer and how it could lead to new cancer sniffing technology.

[If you cannot see the Revver video below, you can click here for a high quality mp4 video.]

Interviewee: Michelle Gallagher, Monell Chemical Senses Center Produced by Sunita Reed — Edited by Sunita Reed and James Eagan Copyright © ScienCentral, Inc.

Detecting Skin Cancer

Skin cancer is the most common type of cancer in the U.S. and for chemist Michelle Gallagher, it hits close to home.

“Skin cancer actually affects a lot of people in my family, so it really made me excited to know that after what they had been through in their diagnosis of skin cancer, there could be in the future a much easier and less painful way to get their diagnosis,” says Gallagher.

Today, Gallagher presented the first odor profile for skin cancer at the American Chemical Society’s annual meeting in Philadelphia. She conducted the study while working as a post-doctoral researcher under George Preti, also a chemist, at the Monell Chemical Senses Center. She now works for Rohm and Haas.

Gallagher and Preti were inspired by previous research reports that dogs, with their superior sniffing abilities, could be trained to detect the scent of cancer. First they studied what compounds are released into the air by healthy skin. Using an instrument that looks like an upside down martini glass, the researchers sampled the air above healthy skin from volunteers who varied in age and gender. The device uses an absorbent fiber that’s exposed to the air above the skin for 30 minutes to collect a sample of the air. The researchers analyzed the chemicals in the samples using gas chromatography and mass spectrometry, and detected 92 chemicals in all.

“What we found is that there are no differences associated with gender, but there were differences associated with age. So some compounds increased or decreased depending on the age of the subject,” explains Gallagher.

In the next phase of their research, they tested air above skin with basal cell carcinoma, the most common form of skin cancer, and compared the results with normal skin. Although the chemicals in both groups were the same, the levels of some chemicals were strikingly different.

“And what we saw was that in the patients that had skin cancer, there was actually an increase in one of the compounds and a decrease in another. And this was true when we compared each healthy subject with each skin cancer patient,” Gallagher says.

Gallagher envisions developing a wand-like “electronic nose” that can be waved over the skin to detect cancer even before visible signs appear. The researchers next plan to study other forms of skin cancer.

Today, doctors diagnose skin cancer by visual examination for suspicious moles or lesions, followed by an invasive biopsy. The researchers hope that their study will lead to earlier diagnosis of skin cancer, which would give doctors a head start in treatment.

Source

Google puts $10 mln into new geothermal technology

LOS ANGELES, Aug 19 (Reuters) - Google Inc (GOOG.O: Quote, Profile, Research) is investing $10 million to produce electricity from underground heat with a breakthrough technology, as the Web search leader extends its clout to clean up the environment.

The move is part of Google's effort to pump hundreds of millions of dollars into green energy sources, starting with solar thermal, high-altitude wind power and now, geothermal energy.

Heat from below the earth's surface could one day be a massive contributor to the nation's electricity supplies because it is available around the clock, Google said.

"It's 24-7, it's potentially developable all over the country, all over the world, and for all that we really do think it could be the 'killer app' of the energy world," Dan Reicher, Google's head of climate and energy initiatives, said in an interview. "Killer app" is a term used to describe revolutionary software.

That new "app," called enhanced geothermal systems, or EGS, improves upon the century-old technology of tapping geothermal energy from geysers, hot springs or volcanoes to generate electricity. With EGS, engineers drill their own geothermal outlets and pump in water to create steam to power a turbine.

The bulk of Google's first geothermal investment, $6.25 million, will help finance EGS company AltaRock Energy Inc of Sausalito, California. Other investors in the company include some of the top Silicon Valley venture capital firms.

About $4 million of Google's money will go to Potter Drilling Inc, a Redwood City, California company which has a hard rock drilling technology.

Enhanced geothermal systems that AltaRock is developing can work in a wider range of geographies than conventional geothermal ones, Google said.

"If you drill deep enough anywhere you can get to hot rock," Reicher said.

The key to keeping the cost of a project down, therefore, is to find hot rocks that lie close to the surface. Nevada has good geothermal resources, Reicher said, as do some Eastern states including West Virginia and Pennsylvania.

To help locate good geothermal resources, Google also announced a $489,521 grant for Southern Methodist University's Geothermal Lab to update geothermal mapping of North America.

Google is part of a $26.25 million round of funding AltaRock announced on Tuesday. Other investors include Microsoft Corp (MSFT.O: Quote, Profile, Research) co-founder Paul Allen's investment firm, Vulcan Capital, and Silicon Valley venture capital firms Khosla Ventures, Kleiner Perkins Caufield & Byers and Advanced Technology Ventures.

Google's previous clean technology investments include $20 million for two solar thermal companies -- eSolar Inc and BrightSource Energy Inc, and $10 million to high-altitude wind company Makani Power Inec. (Editing by Gerald E. McCormick, Steve Orlofsky, Richard Chang)

Optical Computing Closer To Reality

ScienceDaily (Aug. 19, 2008) — Scientists at the University of Pennsylvania have theorized a way to increase the speed of pulses of light that bound across chains of tiny metal particles to well past the speed of light by altering the particle shape.

Application of this theory would use nanosized metal chains as building blocks for novel optoelectronic and optical devices, which would operate at higher frequencies than conventional electronic circuits. Such devices could eventually find applications in the developing area of high-speed optical computing, in which protons and light replace electrons and transistors for greater performance

Recent developments in nanotechnology have enabled researchers to fabricate nanoparticle chains with great precision and fidelity. Penn’s research team took advantage of this technological advance by utilizing metallic nanoparticles as a chain of miniature waveguides that exchange light.

Currently, the advance is theoretical. But, from a practical standpoint, the creation of a metallic nanochain would provide the combination of smaller-diameter optical components coupled with larger bandwidth, making them optimal wave guiding materials.

As the velocity of the light pulse increases, so too does the operating bandwidth of a waveguide. Increasing the bandwidth helps to increase the number of information channels, allowing more information to flow simultaneously through a waveguide.

Researchers investigated changing the shape of particles in an attempt to increase this bandwidth. Spherically-shaped nanoparticles, the shape used almost exclusively in early research, provide narrow bandwidths of light. As Markel and Govyadinov discovered, shaping the particles as prolate, cigar-shaped or oblate, saucer-shaped, spheroids boosted the velocities of surface plasmon pulses reflecting off the surface to 2.5 times the speed of light in a vacuum.

Reshaping the nanoparticles therefore resulted in an enormous increase in the operating bandwidth of the waveguide. As an additional bonus, constructing the chains from oblate spheroids results in decreased power loss as well.

The exceptional combination of small size, large bandwidth and relatively small losses may make these useful as building blocks for the light-based devices of the future.

Researchers have used light and metal to create special electromagnetic wave of electrons on the surface called plasmons for years. Just as light travels through optical fibers, surface plasmons propagate along a chain of closely spaced, metallic particles with each particle acting like a miniature beacon, receiving a signal from its neighbor and transmitting it further along the chain. Although chains of metallic particles are not practical for long-range communication due to rapid power loss, they are well suited for optoelectronic and optical devices in which achieving a small overall size is important.

Markel and Govyadinov’s theory may prove useful in overcoming sizing obstacles that complicate optics. Light cannot travel through an optical fiber if the fiber’s diameter is smaller than a micron. A particle chain like the one proposed by Penn researchers, however, could be as thin as 50 nanometers in diameter, a few hundred times thinner than any optical fiber, and still guide the surface plasmon waves.

An interesting conundrum arises from the work. The theory of relativity prohibits anything from moving faster than light.

“But what is a ‘thing’?” Markel said. “A very powerful flashlight directed at the moon would theoretically create a bright spot on its surface. By simply turning the flashlight sideways, the flashlight’s beam streaks across the sky at speeds far exceeding the speed of light. This evidence has long been known and dismissed, since the bright spot cannot be used for superluminal, or faster-than-light communication, between the earth and the moon. The fast motion of the bright spot is simply a geometrical artifact, similar, in some ways, to the point at which the two blades of closing scissors intersect. The theory of relativity does not concern such purely geometrical objects.”

The researchers believe there are, in fact, some superluminal "things" in nature. For example, it has been long theorized, and was demonstrated in a series of experiments in the last quarter of the 20th century, that electromagnetic pulses, or "wave packets," can propagate through material media with an overall velocity which is greater that the speed of light in vacuum. Although the superluminal wave packets cannot be used to transmit energy or information faster than the speed of light, and therefore do not contradict the theory of relativity, they are fascinating objects and can be utilized in optical communications.

The surface plasmon pulses discovered at Penn belong to the same class of superluminal wave packets. It is predicted that the superluminal properties of these pulses are much bolder than anything previously observed.

Colleagues in the Department of Bioengineering, Alexander A. Govyadinov and Vadim A. Markel, also of the Department of Radiology at Penn, published the study in a recent issue of the journal Physical Review B.

Source

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Adapted from materials provided by University of Pennsylvania.

ITRI US patent - looks like Spindt tips formed of CNT paste

70A = CNT paste pyramidal formation
30 = imprint negative mold

From the patent:
Subsequently, the imprint negative mold 30 dipped with the CNT paste which are mixed with appreciate (sic appropriate) concentration of CNT, silver powder, and organic bonding agent. As is shown in FIG. 6, the CNT paste 70A will be imprinted on the predetermined pixels so as to form emitting sources 80, and the CNT paste 70B in the trenches (the reverse pattern of pillar 20) will not touch with the gate lines 60.

Referring to FIG. 7, a removal of the imprint negative mold 30 is performed.

United States Patent 7,413,763
Chao , et al. August 19, 2008

Method of fabricating carbon nanotube field emission source

Abstract

A method of transferring imprint carbon nano-tube (CNT) field emitting source is disclosed. Firstly, cathode lines are screen printed on a substrate. Then a dielectric layer formation on the cathode lines and substrate is followed. Afterward, gate lines formed on the dielectric layer by screen printing are performed. Next a patterning process is carried out to form openings. Subsequently, an imprint negative mold is dipped with CNT paste and imprinted the CNT paste on the cathode lines through the openings. After drawing of pattern from the imprint mold, the CNT paste is cured by annealing. Since the emitting sources are formed through the imprint negative mold, as a result, the size and shape can be predetermined. Moreover, the intervals between gate line and the emitting source are readily control, which resolve the circuit short problem between gate and cathode. Consequently, the current density, brightness, and uniformity of the emitter sources are significantly improved.

Inventors: Chao; Ching-Hsun (Kaohsiung, TW), Sheu; Jyh-Rong (Hsinchu, TW), Chiang; Liang-Yu (Taipei Hsien, TW), Chang; Yu-Yang (Tainan, TW), Lee; Cheng-Chung (Taitung, TW)

Assignee: Industrial Technology Research Institute (Hsinchu, TW)
Appl. No.: 10/706,907
Filed: November 14, 2003
Source

BTW, I think this ITRI development (read Taiwan/China) will give that FET-Sony (read Japan) nano-Spindt metal tips FED a run for the money! IMHHO, of course.

And...could this ITRI development be what Da Ling was/is waiting for!!!!????

Kanzius lands seed money

BY DAVID BRUCE
david.bruce@timesnews.com [more details]

Published: August 19. 2008 1:10AM

John Kanzius, left, waits near a prototype of the radio-frequency device he invented, at Industrial Sales and Manufacturing Inc., in Millcreek Township on July 23. Steven Curley, M.D., principal investigator for Kanzius' device at M.D. Anderson Cancer Center in Houston, was visiting to see if Erie might host human trials on the device as early as 2010. (Greg Wohlford / Erie Times-News) Zoom | Buy this photo

John Kanzius used to have trouble getting government officials interested in his experimental cancer-treatment device.

Now they seem to be eager to help him.

U.S. Rep. Phil English, of Erie, R-3rd Dist., visited Kanzius' lab Monday to promise $500,000 in federal funding for the external radio-frequency generator. The House Committee on Appropriations has approved the funds, and the House could act on it as early as September, English said.

The bill must still be approved by the full House and Senate and signed by President Bush, though English said "it's very close" to being a done deal.

"This is the kind of project the federal government should support," English said.


English is the latest high-ranking public official to meet with Kanzius. The Millcreek Township inventor had lunch with Gov. Ed Rendell last week, and Kanzius demonstrated his cancer-killing device to Sen. Bob Casey in early July.

Government funding is crucial, Kanzius said, because it can speed research at both M.D. Anderson Cancer Center, in Houston, and the University of Pittsburgh Medical Center.

"Just like when you spread fertilizer on the ground to grow grass more quickly, funding research helps get you results more quickly," Kanzius said.

It will cost about $10 million to fund all of the work needed to take Kanzius' device to human trials, said Steven Curley, M.D., principal investigator for Kanzius' device at M.D. Anderson. The device works by emitting radio waves that heat and destroy cancer cells targeted with tiny pieces of metal, called nanoparticles.

The $500,000 appropriation wouldn't be the first federal appropriation for Kanzius' device -- U.S. Sen. Arlen Specter has helped provide $384,000 in funding for the project -- but it would be the largest.


The money would cover the cost of four researchers at M.D. Anderson or UPMC for an entire year, Kanzius said.

"You're buying time," he said. "You're buying lives."

Interest has grown in Kanzius' device since a "60 Minutes" report aired April 13. It has gained worldwide attention as a possible treatment for a variety of cancers.

"I'm hearing a lot more feedback from the public," English said. "It's something people are aware of and truly support."

Kanzius said continued success at the two research centers has also spurred interest.


"And I believe this is just the tip of the iceberg," Kanzius said. "It's the beginning of a huge groundswell of research dollars."

It's not known how the $500,000 would be divided between UPMC and M.D. Anderson. English said it would be up to the John Kanzius Cancer Research Foundation.

DAVID BRUCE can be reached at 870-1736 or by e-mail.

You can donate to the Kanzius Project by visiting www.johnkanziuscancerresearchfoundation.org or by mailing a check or money order to the John Kanzius Cancer Research Foundation, 915 State St., Erie, PA 16501.

Source

Metals Self-Assemble Into Nanostructures

Cornell researchers have developed a way to self-assemble metals into complex nanostructures. This could lead to far more efficient conductors and breakthroughs in energy technology.

Alexander E. Braun, Senior Editor -- Semiconductor International, 8/18/2008 8:11:00 AM

Ever since mankind first began working metals, the only way to shape them has been the heat-and-beat approach. While this process may have increased in sophistication (nanotech uses e-beams or acids to cut or etch), the basic procedure has remained the same. Now, however, a group of Cornell University (Ithaca, N.Y.) researchers has developed a technique to self-assemble metals into complex nanostructures, which could radically change the traditional millenary process, possibly leading to new types of conductors that can carry more information than any other existing wire.

The research effort is headed by Ulrich Wiesner, professor of materials science and engineering; Francis DiSalvo, J.A. Newman Professor of chemistry and chemical biology; and Sol Gruner, a John L. Wetherill Professor of physics. They have developed a method of coating metal nanoparticles ~2 nm in diameter with a ligand, an organic compound that allows them to be dissolved in a liquid and mixed with a block copolymer composed of two different chemicals whose molecules link together to solidify in a predictable pattern. When the polymer and ligand are removed, the metal particles fuse into a solid structure.

According to Wiesner, this target has been pursued for over two decades. “This is a complex problem, because metals typically have very high surface energies,” he said, adding that nanoscopic metal particles tend to aggregate into clusters. “Once these clusters are formed, they cannot be rearranged. Thus, to get structure control over metals using any sort of a self-assembly process isn’t easy.”

The aggregation issues were overcome by designing particular ligand structures. Ligands are attached to the metal nanoparticles surface, making them soluble in the solvents used in the self-assembly process with the polymers. These also have charges that provide repulsive interactions, so that when they come close, they don’t necessarily click together and form irreversible aggregation states. The repulsive interactions enable them to flow past each other and accommodate structure-formation processes governed by the polymeric species added into the mixture.

By designing the metallic nanoparticles with tailored organic ligands and then working with block copolymers that structure-direct the nanoparticles, it became possible to make, for the first time, nanostructures in what the researchers refer to as the dense nanoparticle regime. The Cornell breakthrough lay in adding a ligand that creates high solubility in an organic solvent, allowing particles to flow even at high densities. The ligand layer surrounding each particle was made relatively thin to ensure that the volume of metal in the final structure would be sufficiently large to maintain its shape after the organic materials were removed.

A solution of ligand-coated platinum nanoparticles was mixed with a block copolymer. The nanoparticles solution combines with only one of the two polymers, and the two polymers assemble into a structure that alternates between small regions of one and the other, producing clusters of metal nanoparticles suspended in one polymer and arranged around the outside of the other polymer’s hexagonal shapes. Depending on the polymers, other patterns can be attained.

The material is then annealed in the absence of air, turning the polymers into a carbon scaffold that supports the shape into which the metal particles have been formed. Finally, the material is heated in air to oxidize the ligands and burn away the carbon. Because metal nanoparticles have a low surface melting point, they sinter into a solid structure.

Chemically self-assembled complex platinum nanostructure with uniform hexagonal ~10 nm pores. (Source: S. Warren and U. Wiesner, Cornell University)

The result was a platinum structure with uniform hexagonal pores ~10 nm across. This could be a significant energy technology development, because platinum is considered the best catalyst available for fuel cells and such a porous structure would enable fuel to flow and react over a larger surface.

Wiesner considers results obtained so far as extremely promising, because this is the first time it has been possible to structure metals in bulk ways. “What you can do with one metal, you can do with mixtures of metals,” he said. In principle, it should be possible to use the approaches developed by Cornell in thin films to lay down metallic structures in silicon solely through self-assembly processes.

“This is exciting,” Wiesner said, “but limited to the polymer’s properties. Being organic materials, polymers aren’t very etch-resistant, lack magnetic properties, and usually don’t offer high electronic conductivity.” However, if instead of working with polymers it were possible to use metal block copolymer composites, then all the desired properties — electron conduction, magnetism, etc. — would be available.

According to Wiesner, the next step is to attempt to do the same thing that they did in bulk, which lacks the surface interactions between the material and substrate, in thin films. It should be possible to lay down in a well-defined way metal lines on a substrate using such a simple self-assembly process.

This has enormous potential for Moore’s Law. “But the devil is typically in the details, and although these preliminary results are extremely promising, it yet remains to be proven whether these self-assembly processes can truly fabricate these kinds of structures on thin film and do so using multiple materials,” Wiesner warned. The researchers used platinum, because it is a good catalyst, and a mesoporous material with a high surface area that lends itself to catalysis applications.

However, for semiconductor applications, it may be necessary to use metal alloys, some of which have strong magnetic properties. There is much to be considered, such as whether these alloys would be nanostructured.

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Immune cells show long-term memory

By Tina Hesman Saey

Web edition : Sunday, August 17th, 2008

Almost a century after exposure to the 1918 Spanish flu, survivors’ white blood cells still recognize the virus

Even after 90 years, the immune system doesn’t forget the face of a mass-murderer. A new study shows that survivors of the 1918 Spanish flu pandemic still have immune cells that remember the culprit virus.

Such long-lived immunity was thought to be impossible without periodic exposure to the microbe that stimulated the immune system in the first place. But a study published in advance online August 17 and slated for an upcoming issue of Nature reveals that immunity to a virus can last nearly a century.

“This is a really extraordinary finding,” says Peter Palese, a virologist at Mount Sinai School of Medicine in New York City who was not involved in the study. “It’s like immunological archaeology.”

Previous research showed that elderly people have antibodies that can recognize the 1918 flu virus, but that those antibodies usually also latch on to more recent viruses of the same subtype as the Spanish flu. The new study demonstrates that the immune system retains a specific memory only for the 1918 virus, which killed more than 20 million people worldwide.

Researchers led by viral immunologist James Crowe of Vanderbilt Medical Center in Nashville, Tenn., found a type of immune memory cell called B cells in the blood of elderly people who had lived through the 1918 Spanish flu pandemic. B cells are white blood cells that make antibodies against specific features of the proteins of an invading microbe.

In the pandemic survivors, about one in every 4.6 million B cells made antibodies that attack the 1918 virus but don’t latch on to more recent flu viruses that resemble the Spanish flu. That results offer evidence that the immune system remembers a virus for decades without being stimulated by reexposure, Palese says.

Although the 1918 pandemic was particularly virulent, the new study suggests the immune system can probably sustain a lifetime’s worth of defense against less deadly diseases as well, Palese says. And good vaccines should produce similar longevity in the immune response, possibly eliminating the need for frequent booster shots, he says.

Antibodies produced by the pandemic survivors are some of the most potent antibodies ever described, says Crowe. Mice given the antibodies and also infected with the 1918 virus survived.

“This is entirely counter to everyone’s intuition — that elderly people would have such potent antibodies,” Crowe says. Aging typically reduces a person’s ability to build antibodies and develop immunity to diseases, so it was a surprise to find that the elderly survivors of the Spanish flu could still mount such a vigorous defense against the virus.

Should the 1918 virus reappear, antibodies from the survivors might be used as a therapy to treat infected people, Crowe suggests. He and his colleagues produce the antibodies from cell cultures of the survivors’ B cells to prevent the need to keep drawing blood from the survivors.

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Pittsburgh researchers developing nanomagnetic cancer therapy

August 6, 2008

Imagine nano-sized magnetic particles capable of fabulous feats such as killing cancer cells in the body, regenerating human tissue and skimming toxic oil spills from lakes and rivers.

Image of oil being pulled by a magnet (last frame) courtesy CMU

Carnegie Mellon University researchers, in collaboration with UPMC Hillman Cancer Center and UPMC McGowan Institute of Regenerative Medicine, are working on pioneering research that may one day save human lives and clean up the environment, all with the help of tiny nanomagnets. They are joined by teams in Berlin and John Hopkins University who are also working toward a breakthrough.

Mike McHenry, professor of material science and engineering at Carnegie Mellon, explains that magnetic nanoparticle research has been ongoing for a decade. The most promising application of this phenomenon is for hyperthermic cancer treatments, heating tissues from 42- to 46-degrees Celsius, a process that selectively eradicates cancer cells while allowing healthy tissue to survive.

“This could be a major breakthrough,” says McHenry. “We wouldn’t have to use chemotherapy to treat cancer, or it could be combined with chemotherapy. The idea is it will enable us to discriminate between healthy and cancerous cells and kill the cancer through a radio frequency field.”

Patients who undergo the localized heat therapy would, at most, experience a warm sensation similar to a high fever, McHenry explains. The research is still in its infancy.

Magnetic nanoparticle dynamics may also be used to reshape and regenerate tissue, research that is in the animal clinical trial stage. With the help of MIT, the biotechnology may also serve as a green method to magnetize and move oil spills from large bodies of water.

The research has been primarily funded through the National Science Foundation.

To see the research in action, click here.

Writer: Debra Smit
Source: Dr. Mike McHenry, Carnegie Mellon University

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Applied Nanotech Trademark for Printing ink, namely conductive ink

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Targeted Single-Wall Carbon Nanotube-Mediated Pt(IV) Prodrug Delivery Using Folate as a Homing Device

Published: 1 hour ago, 14:03 EST, August 15, 2008

Nanotechnology / Bio & Medicine

Platinum-based anticancer agents have a long history as proven therapeutic agents, but their toxicity and short lifetime in the body and the ability of tumors to develop resistance to these drugs limit the ultimate utility of these agents.

In an attempt to overcome these limitations, a multi-institutional research team comprising members from Stanford University, the Massachusetts Institute of Technology (MIT), and the University of Duisburg-Essen in Germany is using targeted carbon nanotubes as delivery agents for an inactive form of platinum that cancer cells themselves convert into a toxic anticancer agent.

Reporting its work in the Journal of the American Chemical Society, the research team headed by Stanford’s Hongjie Dai, Ph.D., a member of the Center for Cancer Nanotechnology Excellence Focused on Therapy Response, and Stephen Lippard, Ph.D., MIT, describes its development of methods to attach platinum-containing compounds firmly to the surface of carbon nanotubes to create what they call a “longboat delivery system” for the platinum warhead.

The particular form of platinum that the researchers use, known as platinum-IV, is capable of binding to other molecules in addition to the nanotube. The investigators use that capability to attach the tumor-targeting agent folic acid to the platinum warhead.

When administered to tumor cells that overexpress a folic acid receptor, the modified nanotubes rapidly enter the target cell. There, enzymes within the cell convert platinum-IV to a far more toxic form known as platinum-II. This chemical conversion has the effect of releasing platinum from the nanotube and enabling it to travel to the cell nucleus, where it reacts with deoxyribonucleic acid (DNA) and eventually kills the cell.

Tests with cancer cells growing in culture showed that this nanotube formulation of platinum is more than 8 times more potent than the approved anticancer agent cisplatin.

This work, which is detailed in the paper “Targeted Single-Wall Carbon Nanotube-Mediated Pt(IV) Prodrug Delivery Using Folate as a Homing Device,” was supported by the NCI Alliance for Nanotechnology in Cancer. An abstract of this paper is available through PubMed.

Provided by National Cancer Institute

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Nano-solution to clean drinking water for a thirsty world

Media Release

August 11 2008

PhD student Chiu Ping Chan shows the new water treatment process

UniSA scientists have discovered a simple way to remove bacteria and other contaminants from water using tiny particles of pure silica coated with an active nano-material.

The water treatment process is a new concept, not used anywhere else in the world, which has the potential to make a significant contribution to the health of nations worldwide.

A recent UNESCO report reveals that more than 6,000 people die every day from water-related diseases, and the availability of drinking quality water, especially in the developing world, is fast becoming a major socio-economic issue.

Current water purification techniques are often complicated and use sophisticated equipment, which is expensive to operate and maintain, and includes a final, costly disinfection stage. This can then result in by-products like trihalomethane, which can have serious effects on human health.

UniSA’s Professor of Nanotechnology and Nanomanufacturing, Peter Majewski will share his findings on the new treatment process at the seminar Surface-engineered silica: water treatment for a thirsty world on Tuesday evening, August 12, as part of the University’s free lecture series, Gift of Knowledge 2008.

“The water treatment process can remove bacteria, chemicals, viruses and other contaminants from water much more effectively than conventional water purification methods,” Prof Majewski said.

“Its major benefits include an easy to use chemical and physical treatment process that cleans water without requiring additional energy, and uses recyclable non-toxic base materials like the waste product silica and water, which bring costs down. These features make it a very attractive alternative to desalination, which incurs high energy costs,” he said.

“UniSA’s nano-solution to water purification has the potential to prevent disease and poisoning of millions of people,” Prof Majewski said.

Testing of the active particles demonstrates that they can remove pathogens such as the Polio virus, bacteria such as Escherichia coli, and the waterborne parasite Cryptosporidium parvum.

“The good news is that it should be available within two years.”

Members of the public are invited to register online to attend the seminar tomorrow, Tuesday August 12, at the Mawson Centre, SA Water Lecture Theatre, Mawson Lakes campus from 6pm – 7pm.
Contacts for interview

* Prof Peter Majewski office (08) 8302 3162 mobile 0423 783 662 email peter.majewski@unisa.edu.au

Media contact

* Geraldine Hinter office (08) 8302 0963 mobile 0417 861832 email geraldine.hinter@unisa.edu.au

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Drawing Circuits with 11 Million Nano Pens

Thursday, August 14, 2008

Cheap arrays of polymer pens can draw precise, complex nanopatterns.

By Katherine Bourzac

Olympic nano pen: These 15,000 gold replicas of the Olympics logo (top) were created using a new lithography technique that relies on large arrays of polymer nano pens writing in parallel. The bottom image shows the logos in close-up, and the inset further zooms in on the “e” in “Beijing,” showing that its bottom stroke is only 90 nanometers wide. The logo of the running man is 36 micrometers high. These images, taken with a scanning electron microscope, demonstrate the range in feature sizes that can be made with the technique. Credit: Science/AAAS

Multimedia Watch dip-pen lithography in action.

The demand for ever faster, cheaper electronics is pushing the lithography-based manufacturing techniques standard in the semiconductor industry to their limits. Now researchers report a cheap, fast lithography technique that uses arrays of flexible polymer nano pens to precisely pattern millions of complex structures in parallel. The technique, which the researchers have used to create an integrated circuit (and lilliputian versions of the Olympics logo), can be employed to make lines whose sizes range from a few nanometers to millimeters thick.

The technique, developed by Chad Mirkin, a chemist at Northwestern University and director of the International Institute for Nanotechnology, uses arrays of pyramid-shaped polymer pens whose tips are dipped in solutions of chemicals that may feature almost any molecule, including proteins and acids; the pens are then traced over a surface by a mechanical arm to create millions of structures in parallel. The width of the lines drawn by each pen can be carefully controlled by varying the force exerted on the flexible pen tips. Because Mirkin's pens trace out designs programmed by computer software, they can quickly switch between complicated designs, making possible the creation of complex patterns whose features are very close together.

Mirkin has used the pens to pattern acid on a silicon wafer coated with gold; he then etched, based on the pattern, a gold integrated circuit. Polymer-pen lithography also shows promise for patterning biological molecules. Indeed, says Mirkin, the technique could work with almost any molecular "ink," including proteins for capturing and studying cells. The arrays of polymer pens cost less than a dollar each to make.

Polymer-pen lithography is an improvement over dip-pen lithography, a technique that Mirkin has been developing since 1999. Dip-pen lithography uses arrays of sharp, stiff cantilevered probes--the same ones used for atomic force microscopy. Mirkin created a company, NanoInk, to commercialize the technology. But, he acknowledges, "its ultimate utility has been limited by problems with throughput, cost, and complexity." The size of its molecular strokes has been restricted to a relatively narrow range, the cantilevers are prone to breaking, and the number of structures that can be made in parallel is limited.

"If this works," says Grant Willson, an engineer at the University of Texas at Austin, "it will speed the process" of patterning structures with nano pens. The new version of dip-pen lithography could make the technology much more commercially practical. But Mirkin's technique will be competing in a crowded field, notes Willson. Researchers aiming to pack circuits with ever smaller features for ever faster chips are taking many different nanofabrication approaches. Some, for example, are creating optical antennas to focus light into very small beams to extend the capabilities of photolithography. Others have turned to beams of electrons or ions, or use heat deformation to form patterns.

Harald Fuchs, director of the Interface Physics Group at the University of Münster, in Germany, says that the major advantage of Mirkin's technique over other nanofabrication methods is precision and flexibility. The pens could be used to write a pattern in one molecular ink, get dipped in another, and then write another layer. To make even more complex patterns, says Fuchs, each pen tip could be dipped in a different ink.

Mirkin says that Northwestern is talking to companies, including his own NanoInk, about commercializing polymer-pen lithography. The technique, he says, will make the dip-pen technology "accessible to a large number of people."

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Scientists Overcome Nanotechnology Hurdle

ScienceDaily (Aug. 13, 2008) — When you make a new material on a nanoscale how can you see what you have made? A team lead by a Biotechnology and Biological Sciences research Council (BBSRC) fellow has made a significant step toward overcoming this major challenge faced by nanotechnology scientists.

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An image from a molecular dynamics simulation showing negatively (red) and positively (blue) charged areas of the nanoparticle. Part of the peptide is shown in the lower half of the frame and the reactive molecule attached in the middle (Credit: Duschesne et al: Supramolecular Domains in Mixed Peptide Self-Assembled Monolayers on Gold Nanoparticles. ChemBioChem. DOI: 10.1002/cbic.200800326. Copyright Wiley-VCH Verlag GmbH & Co. KGaA.)

With new research published August 13 in ChemBioChem, the team from the University of Liverpool, The School of Pharmacy (University of London) and the University of Leeds, show that they have developed a technique to examine tiny protein molecules called peptides on the surface of a gold nanoparticle. This is the first time scientists have been able to build a detailed picture of self-assembled peptides on a nanoparticle and it offers the promise of new ways to design and manufacture novel materials on the tiniest scale - one of the key aims of nanoscience.

Engineering new materials through assembly of complex, but tiny, components is difficult for scientists. However, nature has become adept at engineering nanoscale building blocks, e.g. proteins and RNA. These are able to form dynamic and efficient nanomachines such as the cell's protein assembly machine (the ribosome) and minute motors used for swimming by bacteria.

The BBSRC-funded team, led by Dr Raphaël Lévy, has borrowed from nature, developing a way of constructing complex nanoscale building blocks through initiating self-assembly of peptides on the surface of a metal nanoparticle. Whilst this approach can provide a massive number and diversity of new materials relatively easily, the challenge is to be able to examine the structure of the material.

Using a chemistry-based approach and computer modelling, Dr Lévy has been able to measure the distance between the peptides where they sit assembled on the gold nanoparticle. The technique exploits the ability to distinguish between two types of connection or 'cross-link' - one that joins different parts of the same molecule (intramolecular), and another that joins together two separate molecules (intermolecular).

As two peptides get closer together there is a transition between the two different types of connection. Computer simulations allow the scientists to measure the distance at which this transition occurs, and therefore to apply it as a sort of molecular ruler. Information obtained through this combination of chemistry and computer molecular dynamics shows that the interactions between peptides leads to a nanoparticle that is relatively organized, but not uniform. This is the first time it has been possible to measure distances between peptides on a nanoparticle and the first time computer simulations have been used to model a single layer of self-assembled peptides.

Dr Lévy said: "As nanotechnology scientists we face a challenge similar to the one faced by structural biologists half a century ago: determining the structure with atomic scale precision of a whole range of nanoscale materials. By using a combination of chemistry and computer simulation we have been able to demonstrate a method by which we can start to see what is going on at the nanoscale.

"If we can understand how peptides self-assemble at the surface of a nanoparticle, we can open up a route towards the design and synthesis of nanoparticles that have complex surfaces. These particles could find applications in the biomedical sciences, for example to deliver drugs to a particular target in the body, or to design sensitive diagnostic tests. In the longer term, these particles could also find applications in new generations of electronic components."

Professor Nigel Brown, BBSRC Director of Science and Technology, said: “Bionanotechnology holds great promise for the future. We may be able to create stronger, lighter and more durable materials, or new medical applications. Basic science and techniques for working at the nanoscale are providing the understanding that will permit future such applications of bionanotechnology.”

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Journal reference:

1. Duchesne et al. Supramolecular Domains in Mixed Peptide Self-Assembled Monolayers on Gold Nanoparticles. ChemBioChem, 2008; NA DOI: 10.1002/cbic.200800326

Adapted from materials provided by Biotechnology and Biological Sciences Research Council.

Further evidence to link EBV virus infection with MS

Mon 30 Jun 2008

New research published in The Journal of Experimental Medicine has provided more evidence that a common human virus called Epstein Barr Virus (EBV) plays an important role in the development of MS.

EBV, the virus which causes glandular fever, has been linked to MS for over 30 years. Several studies appear to have shown that people with MS have been exposed to EBV and that EBV is active in their bodies during MS attacks.

In MS, lesions (or plaques) are patches in the central nervous system where inflammation has resulted in the loss of myelin, the protective sheath which surrounds nerve fibres. This study on 22 people with MS demonstrated that EBV is present in the lesions that attack myelin in almost all of the cases examined (21 out of 22).

The researchers propose that EBV is carried across the blood-brain barrier by a certain type of immune cell called B cells, the cells of the immune system that make antibodies. EBV infected B cells which accumulated in lesions were shown to be a common feature of MS, and the number of EBV infected cells correlated with the degree of brain inflammation.

The absence of EBV infected B cells in other inflammatory neurological conditions indicates that this may be specific to MS and not a general phenomenon driven by inflammation.

It is worth noting that EBV is one of the most common viruses in the environment, with up to 90 per cent of the population thought to have been infected by it at some time, most of whom do not go on to develop MS.

There is not yet enough data to prove that EBV infection causes MS. There needs to be further research to explain the link between EBV infection and MS.

Source 1
Source 2 (for date)


ARTICLE

Dysregulated Epstein-Barr virus infection in the multiple sclerosis brain

Barbara Serafini¹, Barbara Rosicarelli¹, Diego Franciotta², Roberta Magliozzi³, Richard Reynolds³, Paola Cinque⁴, Laura Andreoni², Pankaj Trivedi⁵, Marco Salvetti⁶, Alberto Faggioni⁵, and Francesca Aloisi¹

¹ Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, 00161 Rome, Italy
² Laboratory of Neuroimmunology, IRCCS Neurological Institute C. Mondino University of Pavia, 27100 Pavia, Italy
³ Department of Cellular & Molecular Neuroscience, Imperial College Faculty of Medicine, Charing Cross Hospital Campus, London W6 8RF, UK
⁴ Division of Infectious Diseases, San Raffaele Scientific Institute, 20127 Milano, Italy
⁵ Institute Pasteur-Cenci Bolognetti Foundation, Department of Experimental Medicine, University of Rome La Sapienza, 00161 Rome, Italy
⁶ Department of Neurology and Centro Neurologico Terapia Sperimentale (CENTERS), Ospedale S. Andrea, University of Rome La Sapienza, 00189 Rome, Italy

CORRESPONDENCE Francesca Aloisi: fos4@iss.it

Epstein-Barr virus (EBV), a ubiquitous B-lymphotropic herpesvirus, has been associated with multiple sclerosis (MS), an inflammatory disease of the central nervous system (CNS), but direct proof of its involvement in the disease is still missing. To test the idea that MS might result from perturbed EBV infection in the CNS, we investigated expression of EBV markers in postmortem brain tissue from MS cases with different clinical courses. Contrary to previous studies, we found evidence of EBV infection in a substantial proportion of brain-infiltrating B cells and plasma cells in nearly 100% of the MS cases examined (21 of 22), but not in other inflammatory neurological diseases. Ectopic B cell follicles forming in the cerebral meninges of some cases with secondary progressive MS were identified as major sites of EBV persistence. Expression of viral latent proteins was regularly observed in MS brains, whereas viral reactivation appeared restricted to ectopic B cell follicles and acute lesions. Activation of CD8⁺ T cells with signs of cytotoxicity toward plasma cells was also noted at sites of major accumulations of EBV-infected cells. Whether homing of EBV-infected B cells to the CNS is a primary event in MS development or the consequence of a still unknown disease-related process, we interpret these findings as evidence that EBV persistence and reactivation in the CNS play an important role in MS immunopathology.

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Abbreviations used: AID, activation-induced cytidine deaminase; CNS, central nervous system; CSF, cerebrospinal fluid; EBER, EBV-encoded small nuclear mRNA; EBNA, Epstein-Barr nuclear antigen; HHV-6, human herpesvirus 6; LMP, latency membrane protein; MOG, myelin oligodendrocyte glycoprotein; MS, multiple sclerosis; OCB, oligoclonal IgG band; RA, rheumatoid arthritis.

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Full Text

Perhaps a note to
Francesca Aloisi: fos4@iss.it
Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, 00161 Rome, Italy
is indicated noting Nanoviricides' interest and capabilities suggesting a cooperative approach to remove EBV from the MS picture.

NanoVector: making the technology of the ultra-small pay

August 11, 2008

By Allan Maurer

RALEIGH, NC—When a company such as NanoVector, which is developing a plant virus as a nanoparticle drug delivery system gets ready to go to market, its scientific founders turn to experienced entrepreneurial execs. “The key skill needed is the ability to raise money,” says NanoVector CEO Albert Bender.

Bender, a PhD in electrical engineering, started his first company in 1982. “Most were in telecom, datacom, software and hardware, Bender says of his four venture-backed startups. “Drug delivery is not my area of expertise, but the skills needed to start and run a company are the same.

“The key skill is the ability to raise money. Whether it is with angel investors or venture capital, you want someone who has done it before. This market is not interested in inexperienced management teams, even if the opportunity is interesting.”

During his career, Bender has raised 10 rounds of venture capital totaling $150 million for his startups. Three of them sold for good investor returns. He has contacts with 350 North American-based venture capitalist partners.

The typical mid-sized venture firm gets more than 1,000 business plans a year, he notes. They invest in fewer than 10. “So,” says Bender, “They have lots to choose from. You have to ask, how does yours compare?”

“We think we have a homerun with NanoVector,” he says. The company is seeking about $600,000 in seed money to develop its unique drug delivery technology. “We’re about a third of the way there,” says Bender. “We’re getting good traction with some angel groups.”

The seven-year old company has experimented with a variety of nanoparticles. A recent breakthrough using a plant virus demonstrated effective targeting and delivery of a drug payload, overcoming many problems they faced with metal-based nanoparticles. The company bases its technology on research by two North Carolina State University professors.

Most research on nanoparticles is still focused on synthetic particles. “We think we will set a whole new paradigm,” says Bender.

(See part one of the NanoVector story at: NanoVector virus may solve nanoparticle drug delivery problems: http://techjournalsouth.com/news/article.html?item_id=5888)

Bruce Oberhardt, president and chief scientific officer of the firm, says, “The amazing thing to me is how this technology solves so many problems other technologies have been unable to solve.”

For one thing, he says, manufacturing the plant virus-based nanoparticle becomes “trivial” compared to making synthetic particles. “I think this will break away from the pack,” he says.

NanoVector’s angel round would advance the company to the point where it can attract the attention of larger venture firms. It would seek second round of about $7.5 million.

NanoVector is developing a plant nanoparticle drug delivery system initially targeting anti-cancer therapeutics. “It is considered a medical device,” says Bender. That’s important because the regulatory hurdles to get a medical device FDA approved are considerably less arduous for a medical device than for an experimental drug.

Once perfected, the company’s plant nanoparticle could be used as a platform to deliver cancer-targeted reformulations of existing drugs, making them more effective with less toxicity to normal cells.

“You still have to go through pre-clinical animal studies, toxicity and safety studies,” notes Bender, “but you do fewer human trials.” That saves time and money, he points out. The company currently plans to license the technology to large pharmaceutical companies to complete expensive Phase III trials.

While the technology can target a number of chronic diseases, NanoVector will focus on several specific caners initially.

“We can target the nucleus of a cell,” Bender explains. “We own the patent position on that and it enables us to very effectively target cancer cells and kill them.”

Markets for cancer therapies are immense. The North American market for breast and colon/rectal cancers alone will reach $20 billion a year by 2010, and globally, $65 billion in the same period.

“We are about three years from the clinic,” says Bender. “We hope to be doing trials in humans in three years, but we have a lot of work to do.” That includes the animal, toxicity and safety testing.

On the Web: www.nanovectorinc.com

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Coated Film As A Bacteria Killer

ScienceDaily (Aug. 11, 2008) — A nanoproduct made from silver and calcium phosphate and developed by ETH Zurich researchers is lethal to bacteria. Its special feature is that the bacteria themselves invoke and dispense this disinfectant effect.

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The diagram shows the self-disinfecting action of the silver and calcium phosphate nanoparticles applied to the plastic film. (Credit: Image courtesy of Swiss Federal Institute Of Technology)

The fact that silver is an antiseptic and thus a disinfectant has been known for about 3000 years. This is why well-to-do households used silver cutlery, which has an antibacterial effect, while poorer people put silver coins in their milk jugs.

Silver was used medicinally for around two hundred years before it was replaced by antibiotics, and, for a long time, practically its only remaining use was in alternative medicine. The noble metal has undergone a kind of renaissance in medicine since the start of the nanotechnology era. Medical instruments, artificial limbs, hospital furniture or even hospital linen are lined, sheathed or fortified with it.

Nutrient substrate activates the mechanism

However, until now it has been impossible to use the noble metal in a specific, controlled amount. The research group led by Wendelin Stark, Assistant Professor at the Institute for Chemical and Bioengineering of ETH Zurich, has now developed a plastics film coated with silver and calcium phosphate that fulfils these conditions and, in addition, is self-disinfecting.

For example, the combination of the two substances has an effect on the bacterium Escherichia coli that is up to 1000 times more lethal than conventional silicon-based silver preparations. One decisive factor appears to be that the bacteria use the calcium substrate for their metabolism. The calcium phosphate particles, 20 to 50 nanometres in size, are absorbed by the micro-organisms as food and are thereby disintegrated. This releases thousands of tiny silver particles measuring 1 to 2 nanometres which the researchers had coated onto the calcium nutrient.

According to current knowledge, silver nanoparticles have multiple effects on bacteria: they suppress the cell’s nutrient transport, attack the cell membrane and interfere with cell division and thus with the reproduction of the germs. Experiments with the carrier substances calcium phosphate and silicon dioxide, each coated with silver, showed different effects on various bacterial strains in the test.

The calcium phosphate substrate had an efficiency factor of up to 1000 times stronger than silicon dioxide. Within 24 hours, less than one bacterium out of 100,000 to 1,000,000 bacteria survived. However, according to the researchers, since the consumption of the organic calcium phosphate also nourishes the bacteria – without the effect of the silver, they would multiply thousand-fold in 24 hours – the silver must fight not only the bacteria that already exist but also those that would newly form. Wendelin Stark says, “This makes the effect even more astonishing.”

Reducing the risk of infection

The new product has enabled Stark’s group to successfully develop a preparation that is effective against a series of pathogenic bacteria and which becomes active in a targeted manner and in the correct dose only if a bacterium is present. The silver adhering to the calcium phosphate is only released in a quantity corresponding to the amount of calcium phosphate consumed by the bacterium. This saves costs, is efficient and is less stressful for the human body. The product is already being manufactured by the Perlen Converting AG Company in Perlen near Lucerne, which was involved in the development.

This involves coating a film with nanoparticles of silver and calcium phosphate. The film can be used in hospitals, for example, hotspots for germ transmission. Door handles, beds or sanitary equipment onto which the self-disinfecting film is stuck could protect patients from dreaded and dangerous hospital pathogens that can lead to complications, for example after surgical operations. It must be renewed from time to time because the bacteria consume and use up the calcium, so the film is not effective indefinitely.

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Journal reference:

1. Loher S, Schneider OD, Maienfisch T, Borkony S, Stark WJ. Micro-organism-Triggered Release of Silver Nanoparticles from Biodegradable Oxide Carriers Allows Preparation of Self-Sterilizing Polymer Surfaces. Small, 2008; 4 (6), 824-832 DOI: 10.1002/smll.200800047

Adapted from materials provided by Swiss Federal Institute Of Technology.

Flexible nanoantenna arrays capture abundant solar energy

Posted: August 10, 2008

(Nanowerk News) Researchers have devised an inexpensive way to produce plastic sheets containing billions of nanoantennas that collect heat energy generated by the sun and other sources. The technology, developed at the U.S. Department of Energy's Idaho National Laboratory, is the first step toward a solar energy collector that could be mass-produced on flexible materials.

While methods to convert the energy into usable electricity still need to be developed, the sheets could one day be manufactured as lightweight "skins" that power everything from hybrid cars to iPods with higher efficiency than traditional solar cells, say the researchers, who report their findings Aug. 13 at the American Society of Mechanical Engineers 2008 2nd International Conference on Energy Sustainability in Jacksonville, Fla. The nanoantennas also have the potential to act as cooling devices that draw waste heat from buildings or electronics without using electricity.

The nanoantennas target mid-infrared rays, which the Earth continuously radiates as heat after absorbing energy from the sun during the day. In contrast, traditional solar cells can only use visible light, rendering them idle after dark. Infrared radiation is an especially rich energy source because it also is generated by industrial processes such as coal-fired plants.

"Every process in our industrial world creates waste heat," says INL physicist Steven Novack. "It's energy that we just throw away." Novack led the research team, which included INL engineer Dale Kotter, W. Dennis Slafer of MicroContinuum, Inc. (Cambridge, Mass.) and Patrick Pinhero, now at the University of Missouri.

The nanoantennas are tiny gold squares or spirals set in a specially treated form of polyethylene, a material used in plastic bags. While others have successfully invented antennas that collect energy from lower-frequency regions of the electromagnetic spectrum, such as microwaves, infrared rays have proven more elusive. Part of the reason is that materials' properties change drastically at high-frequency wavelengths, Kotter says.

The researchers studied the behavior of various materials -- including gold, manganese and copper -- under infrared rays and used the resulting data to build computer models of nanoantennas. They found that with the right materials, shape and size, the simulated nanoantennas could harvest up to 92 percent of the energy at infrared wavelengths.

The team then created real-life prototypes to test their computer models. First, they used conventional production methods to etch a silicon wafer with the nanoantenna pattern. The silicon-based nanoantennas matched the computer simulations, absorbing more than 80 percent of the energy over the intended wavelength range. Next, they used a stamp-and-repeat process to emboss the nanoantennas on thin sheets of plastic. While the plastic prototype is still being tested, initial experiments suggest that it also captures energy at the expected infrared wavelengths.

The nanoantennas' ability to absorb infrared radiation makes them promising cooling devices. Since objects give off heat as infrared rays, the nanoantennas could collect those rays and re-emit the energy at harmless wavelengths. Such a system could cool down buildings and computers without the external power source required by air-conditioners and fans.

But more technological advances are needed before the nanoantennas can funnel their energy into usable electricity. The infrared rays create alternating currents in the nanoantennas that oscillate trillions of times per second, requiring a component called a rectifier to convert the alternating current to direct current. Today's rectifiers can't handle such high frequencies. "We need to design nanorectifiers that go with our nanoantennas," says Kotter, noting that a nanoscale rectifier would need to be about 1,000 times smaller than current commercial devices and will require new manufacturing methods. Another possibility is to develop electrical circuitry that might slow down the current to usable frequencies.

If these technical hurdles can be overcome, nanoantennas have the potential to be a cheaper, more efficient alternative to solar cells. Traditional solar cells rely on a chemical reaction that only works for up to 20 percent of the visible light they collect. Scientists have developed more complex solar cells with higher efficiency, but these models are too expensive for widespread use.

Nanoantennas, on the other hand, can be tweaked to pick up specific wavelengths depending on their shape and size. This flexibility would make it possible to create double-sided nanoantenna sheets that harvest energy from different parts of the sun's spectrum, Novack says. The team's stamp-and-repeat process could also be extended to large-scale roll-to-roll manufacturing techniques that could print the arrays at a rate of several yards per minute. The sheets could potentially cover building roofs or form the "skin" of consumer gadgets like cell phones and iPods, providing a continuous and inexpensive source of renewable energy.

Source: Idaho National Laboratory

Source

NanoVector virus may solve nanoparticle drug delivery problems

August 8, 2008

By Allan Maurer

RALEIGH, NC—North Carolina State University professor Stefan Franzen first learned about a distinctive plant virus when he met his colleague Steven Lommel over a beer in Poland several years ago. He did not immediately realize that the meeting would lead to a new approach to nanoparticle drug delivery.

“We got a little bit lucky there,” says Franzen, who holds a PhD in biophysical and biological chemistry. “Serendipity is part of science too.”

“I had known Steve for a long time,” he says. “When I first learned of the properties of the plant virus he was studying, I didn’t get it. I was staring at it for a year without seeing why it is so advantageous. Then, it began to sink in.”

Franzen and his company, NanoVector, had been “playing with nanoparticles for a while,” in particular gold nanoparticles, for use as a targeted drug delivery mechanism. They presented difficult problems that did not show signs of being solved.

Problems with metal nanoparticles
At first Franzen thought Lommel’s plant virus might work with his gold nanoparticles, and even published some work related to the possibility. But eventually, he decided the gold nanoparticles just had too many disadvantages that “All these people who want to promote metal nanoparticles have to solve,” he says.

Lommel, a Ph.D., is a professor of plant pathology, professor of genetics, and Associate Vice-Chancellor for Research at NCSU. His primary research program is in the areas of plant virology, plant viral pathogenesis and plant genomics. He has been working with plant viruses since 1978.

The Eureka! Moment
Recalling that initial meeting in Poland six or seven years ago, Lommel says, “Stefan and I knew each other from NCSU, but didn’t know each other’s research. We shared a hotel and talked a lot. I told him we had just learned to open and close my virus and that it has a hollow cavity in it.”

That is what eventually led to the “Eureka!” moment, he says. Together, Franzen, Lommel, and Bruce Oberhardt, who had been with the company from its inception, revived the inert NanoVector.

“Since then, we have been developing it,” says Lommel of the "plant nanoparticle."

“Its natural properties give it a real advantage," he says. "It can open and close without falling apart. It has a lot of flexibility and potential.”

He points out that NanoVector is not making a drug, but rather a “drug formulation.” It will allow the company to package many current cancer drugs that are not targeted to cancer cells. Targeting drugs is the whole basic idea behind nanoparticle delivery.

Untargeted drugs that affect your healthy cells as well as cancer cells are why your hair falls out during chemotherapy.

To target, “You want to sequester the drug,” says Franzen. “You want it to go into something. You can do some clever things with polymers, but this is more elegant. It’s easier to control and has the advantage of thousands of years of evolution.”

Franzen and Lommel have had several “epiphanies” over the years since sharing beers in Poland. Recently, they realized the plant virus has a natural loading and unloading mechanism built into it. “It’s an exquisite calcium sensor,” Franzen says.

It has a lot of “up potential
Although it may take additional months of research, that finding means they can control the loading and unloading of the medicine in the virus via calcium.

NanoVector is initially targeting cancer therapies, but Franzen says that once the company overcomes regulatory issues, the system could be used to administer pain drugs or any other targeted medicines. “It has a lot of up potential,” he says.

Lommel notes that the company has received grant money and funding from private sources. “We’re doing a dance with some angel investors now,” he says.

The company brought in serial entrepreneur Albert Bender, also a PhD, who was founder and CEO of four venture-backed startups, as CEO.

“We have a division of labor here,” says Lommel. “I’m not doing the business side after spending the last 30 years studying plant viruses.”

MONDAY: Part Two: The business side of NanoVector.

Source

NanoVector
http://www.nanovector.it/
http://www.nanovector.it/brochure_nanovector.pdf

J Am Chem Soc. 2007 Aug 18; : 17705477 (P,S,E,B,D)

Encapsidation of Nanoparticles by Red Clover Necrotic Mosaic Virus.

Lina Loo, Richard Guenther, Steven Lommel, Stefan Franzen

Icosahedral virus capsids demonstrate a high degree of selectivity in packaging cognate nucleic acid genome components during virion assembly. The 36 nm icosahedral plant virus Red clover necrotic mosaic virus (RCNMV) packages its two genomic ssRNAs via a specific capsid protein (CP) genomic RNA interaction. A 20-nucleotide hairpin structure within the genomic RNA-2 hybridizes with RNA-1 to form a bimolecular complex, which is the origin of assembly (OAS) in RCNMV that selectively recruits and orients CP subunits initiating virion assembly. In this Article, an oligonucleotide mimic of the OAS sequence was attached to Au, CoFe2O4, and CdSe nanoparticles ranging from 3 to 15 nm, followed by addition of RNA-1 to form a synthetic OAS to direct the virion-like assembly by RCNMV CP. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements were consistent with the formation of virus-like particles (VLPs) comparable in size to native RCNMV. Attempts to encapsidate nanoparticles with diameters larger than 17 nm did not result in well-formed viral capsids. These results are consistent with the presence of a 17 nm cavity in native RCNMV. Covalent linkage of the OAS to nanoparticles directs RNA-dependent encapsidation and demonstrates that foreign cargo can be packaged into RCNMV virions. The flexibility of the RCNMV CP to encapsidate different materials, as long as it is within encapsidation constraint, is a critical factor to be considered as a drug delivery and diagnostic vehicle in biomedical applications.

Source

Viral cargo delivery

14 January 2008

US chemists have used a virus capsule to package and release molecules, which could lead to targeted delivery of therapeutic compounds.

Stefan Franzen and his colleagues at North Carolina State University in Raleigh used the red clover necrotic mosaic virus as a vehicle for dye molecules that can be loaded and unloaded on demand.

Pores in the capsids can be opened and closed to load or empty their cargo.

Red clover necrotic mosaic virus is a plant virus with a protein shell, or capsid, of multiple subunits that self-assemble to form a cage. Franzen explained that, 'these protein cages offer a rigid structure with an interior cavity that can function as an ideal container for cargo encapsulation'.

To explore its versatility for nano-packaging and delivery, Franzen first worked on capturing dye molecules into the capsid. As divalent ions are integral to the virus structure, Ca²⁺ and Mg²⁺ depletion in the solution induces significant conformational changes. This leads to surface pores forming, allowing dye molecules to infuse into the interior cavity. Restoring the ion balance closes the pores, trapping the dye inside the virus. When Franzen lowered the ion concentration, the pores reopened and the dye molecules were released.

Franzen's final aim is to use the capsids for intracellular drug delivery - the next stage is to study their ability to package and deliver cargo into a target cell, he explained. The idea is that loaded viruses should be triggered to open their surface pores and release their package inside a cell where the divalent ion concentrations are low. This concept is 'advantageous because the virus capsid will be able to act as container to protect a cargo until it reaches the targeted cell to be released', explained Franzen.

Michael Spencelayh

Source

Friday, November 16, 2007

Researchers after $2.5M to fund novel drug-delivery idea

[SNIP]

Xiao Xiao, a professor of gene therapy at the University of North Carolina School of Pharmacy, says NanoVector's technology is promising because plant viruses will not infect humans and because human cells do not have a defense mechanism against a plant virus.

The drawback, Xiao says, is that once the plant virus enters a cell, the body will remember and develop a defense system within several weeks. If extended treatment is needed, he says, the body would start to block the virus.

"There's no easy way around that problem," Xiao says.

Bender, CEO of NanoVector, admits that resistance could be a problem. He says the company will research the body's immune response to plant viruses in the coming months.

Source

Stretching the boundaries of electronics

Aug 7, 2008

Physicists in Japan have found a way to disperse carbon nanotubes into a liquid polymer in order to create a rubbery material that conducts electricity. The inventors say that their material, which is more conductive than other elastic materials, is an important step towards realizing “stretchy” electronics for robotics and other electronic devices.

In the past when researchers have tried to create nanotube–polymer composites, strong intermolecular forces between the nanotubes has always made the structures clump together, producing a weak material. However, by grinding nanotubes with an ionic liquid, the Japanese group — led by Takao Someya from the University of Tokyo — has managed to make them evenly dispersed.

Using this technique, the researchers can swap as much as a fifth of the polymers’s weight for nanotubes without reducing its mechanical flexibility. The resulting material — fused with the electrical conductivity of nanotubes — can be stretched up to 70% without being damaged (Science Express 10.1126/science.1160309).

“This expands the application horizon of carbon nanotubes in an important new direction” says Ray Baughman at the University of Texas. “The most surprising discovery is that the addition of up to 20 %wt nanotubes does not reduce elastic deformability”.

Stretchy electronics

While many engineers focus their efforts on miniaturizing electronic devices, the pursuit of stretchy electronics presents engineers with some altogether different challenges. Desirable materials need to exhibit both excellent electronic performance and physical robustness.

Early attempts to make stretchy electronics have tended to either embed standard electronic components in rubber or to directly integrate them with plastic films. Although Someya recognizes there have been some significant advances, he believes devices have been held back by inelastic wiring.

Someya’s team begin creating their stretchy electronic material by grinding nanotubes with an ionic liquid of 1-butyl-3-methylimidazolium bisimide. They add the resulting thick, black paste or “bucky gel” to a liquid polymer and spread it on a glass plate. Finally, they coat it with silicone rubber and leave it to set.

Currently the team are optimizing the electric and mechanical properties of their elastic conductors. They are also investigating new economical printing processes which could enable the material to replace the fine wires in integrated circuits.

As well as improving existing technologies, Someya hopes the elastic conductors will open the doors to applications that have been closed for conventional silicon-based electronics — for example, electronic artificial skins.James Dacey is an intern with physicsworld.com

About the author

James Dacey is an intern with physicsworld.com

Source

For Nanotech Drug Delivery, Size Doesn't Matter--Shape Does

A team of researchers has found that rod-shaped nanoparticles are much more likely to penetrate cells than those shaped like spheres

By Larry Greenemeier

PRODUCING NANOTECH IN BULK: University of North Carolina at Chapel Hill chemistry professor Joseph DeSimone holds a drum of Particle Replication in Non-wetting Templates (PRINT) molds designed to make different-shaped nanoparticles in bulk.
Courtesy of the University of North Carolina at Chapel Hill

As nanotechnology to ferry drugs to their destinations is tested in both the laboratory and in clinical trials, scientists have made a surprising discovery about the kinds of nanoparticles that might be most effective for eventually transporting a number of different cancer-fighting therapies throughout the body.

The conventional wisdom is that the smaller, the better. But that may not be true, according to a team of scientists led by University of North Carolina at Chapel Hill (U.N.C.) chemistry professor Joseph DeSimone. DeSimone and his colleagues have shown that the shape of these microscopic drug carriers is much more important than size and can even mean the difference between whether a drug penetrates target cells effectively or ends up as a target itself, only to be destroyed by the immune system.

Although logic would dictate that the smaller the particle, the more likely it is to infiltrate a cellular membrane, the researchers found that rodlike particles are able to get in faster than other shapes because of how the immune system responds to them. "Clearly," DeSimone says, "there's a role here between size and shape that has not been established before."

The research, published this week in the Proceedings of the National Academy of Sciences USA (PNAS), indicates that rod-shaped particles (150 nanometers in diameter by 450 nanometers long) penetrated human cells about four times faster and traveled farther into the cells than particles with more balanced dimensions (such as 200 nanometers by 200 nanometers). One nanometer equals 40 billionths of an inch.

"If we go back 10 years and ask what is the most important parameter [to developing a therapeutic particle], people would immediately think of the particle's size and then its surface chemistry," says University of California, Santa Barbara, chemical engineering professor Samir Mitragotri, who develops microscopic particles of different shapes and tests their ability to deliver drugs in animals, but was not associated with DeSimone's study. "Now people are realizing that shape can have an impact, too."

One of the hopes is that once nanotechnology is proved safe and effective as a drug delivery system, highly concentrated nanoparticles carrying drugs could be injected directly into the body where they are needed most and use their shape to get to work quickly. Being able to make particles in a variety of shapes out of any organic material could, for example, allow a person suffering from rheumatoid arthritis or Crohn's disease to get their medication in a single injection rather than via a two-hour intravenous infusion of Remicade. "You want to deliver it where you want it, when you want it, without wasting it." DeSimone says.

Nanoparticles shaped a particular way might also keep drugs out of organs they are likely to damage, improving the safety of certain drugs. "We have demonstrated that we have low uptake in the kidneys of animals of our 200-nanometer diameter cylindrical particles that are 200 nanometers in height," DeSimone says, adding that it's not yet clear exactly why shape affects uptake in kidneys. Researchers are hoping that other shapes, such a flexible, wormlike nanoparticle that is 80 nanometers in diameter and 500 nanometers long, will perform even better.

So why do particular shapes work better? For one thing, rod or worm-shaped particles are harder than spherical particles for the body's immune system to reject. "Macrophages, the cells that engulf foreign particles and take them out of circulation, like to eat objects that don't require them to expand a lot," says Mitragotri. "If macrophages come at one of these wormlike particles from the side, they have to expand a lot to engulf them, and they don't like that." It's much less likely that a macrophage would latch onto the pointed end of an elongated particle because the ends are such a small proportion of the particle's total surface area, he adds.

"We believe that wormlike particles will be a challenge for macrophages to engulf and clear,” DeSimone says, “because such filamentous objects are known to be difficult for macrophages to reel in. Particles that are more spherically symmetric can be engulfed in one fell swoop by macrophages, but that is more difficult for such filamentous particles."

The findings of DeSimone and his team are a surprising but welcome development in the use of nanotechnology for drug delivery, says Christian Melander, an assistant professor of organic chemistry at North Carolina State University in Raleigh, who has been studying the use of gold nanoparticles as a means of assisting the delivery of an HIV (human immunodeficiency virus) treatment that is under development as well as to help that drug to latch onto receptors (protein molecules embedded in a cell's membrane) on the outside of T cells to shield them from HIV.

Although Melander and his colleagues at N.C. State and the University of Colorado at Boulder work with an inorganic substance (gold) and cannot alter the shape of the particles they work with, Melander says that DeSimone's work "shows insight into particle delivery that most people wouldn't have predicted. It also shows there's a lot more fundamental research in this area that must be done." Melander's team, which is not involved in any of DeSimone's work, is currently testing their gold nanoparticles' ability to cross through a simulation of the blood–brain barrier that prevents many substances from passing into the brain from the bloodstream.

To help get their technology into drug companies' hands more quickly, DeSimone and his colleagues have built a device that make different-shaped nanoparticles in bulk using molds that pop out these particles like so many ice cubes. The Particle Replication in Nonwetting Templates (PRINT) technology helped earn DeSimone this year's $500,000 Lemelson–M.I.T. Prize in June. "We use lithography to make one wafer that will be the master template (for the nanoparticles)," he says. "From there, we're able to make thousands of linear feet of molds."

DeSimone and his colleagues have been able to make these mini molds since 2005, and published a paper in the Journal of the American Chemical Society at the time describing their work. Those molds were only 0.04 inch (one millimeter) square and yielded very few nanoparticles of controlled size and shape. However, "we can now make many square meters of molds in a cost-effective manner that allows us to make hundreds of milligrams of nanoparticles of a variety of shapes and sizes that allow us to probe biological systems," DeSimone says.

The next step is for Liquidia Technologies, the North Carolina–based company DeSimone co-founded in 2004 with a group of U.N.C. researchers, to refine the printing methods and scale up production. Liquidia has built a machine that yields tens of grams of nanoparticles in a single day, and the company hopes to be able to produce multiple kilograms of nanoparticles daily. He is hoping to have U.S. Food and Drug Administration–approved equipment in place by the middle of 2009 to produce these nanoparticles and move into clinical trials shortly thereafter. First on DeSimone's list to study are siRNA (short interfering RNA) molecules that may be able to keep cancer cells from producing the proteins that make them dangerous as well as the cancer drugs docetaxel, cisplatin and doxorubicin.

Source

Carbon tubes, but not nano

By Davide Castelvecchi

Web edition : Wednesday, August 6th, 2008

New filaments could be more practical than nanotubes

NON-NANOTUBES
Much larger than carbon nanotubes, the newly discovered colossal carbon tubes are visible to the naked eye and have an unusual structure, shown here in a sketch.
Peng et al.

Take solace, all ye who’ve grown weary of carbon nanotube promises: The latest tubes are anything but nano.

While trying to grow better, longer nanotubes, researchers accidentally discovered a new type of carbon filament that’s tens of thousands of times thicker. Christened “colossal carbon tubes,” the new structures aren’t quite as strong as nanotubes but are still 30 times stronger than Kevlar per unit weight, and are potentially easier to turn into applications, suggests a new study in an upcoming Physical Review Letters.

Though exceptionally strong, nanotubes are hard to weave into larger fibers. Labs around the world have been trying to grow longer tubes or to string tubes together because long nanotube fibers could lead to futuristic products, such as ultralight bulletproof vests or even cables that could lift cargo into space at a fraction of the cost of a rocket. But researchers have had only partial success.

Recently at Los Alamos National Laboratory in New Mexico, materials scientist Huisheng Peng and his collaborators were trying to tweak the conditions inside a vacuum oven to grow “forests” of long nanotubes from carbon gas. When Peng opened the vacuum-sealed door, he saw a scene that could be compared to the floor of a barber’s shop: Thin, black hairs were scattered everywhere.

Carbon nanotubes are not visible to the naked eye. “At first, I thought they were a lot of carbon nanotubes bonded together,” says Peng, who recently moved to Los Alamos from Fudan University in Shanghai, China.

Lab tests, however, revealed that the filaments, which can be centimeters long and as thick as one-tenth of a millimeter, were not clumps of nanotubes, but a new and unusual kind of structure. Using X-rays, the team found that carbon atoms form the same type of bonds in the colossal tubes as in nanotubes. The atoms are also arranged in the same hexagonal webs, which resemble chicken wire.

Instead of being simple cylindrical structures, the colossal tubes have two concentric layers. The researchers believe that each layer is made of many chicken wire sheets sandwiched together. Walls that are 100-nanometers thick connect the layers and divide the space between the layers into canals that run along the entire length of the tubes — similar to the gaps inside corrugated cardboard.

The colossal tubes are easily bent and stretched, and at least twice as strong as the strongest fibers made from carbon nanotubes to date, the researchers report. These tubes are also light and good electrical conductors.

László Forró of the Ecole Polytechnique Fédérale in Lausanne, Switzerland, believes that the authors may have rushed to publication with results that are too preliminary. “At this stage it is only a cookbook,” he says. “Basically, they do not know anything about the structure.”

The researchers say their tests suggest a structure similar to bundles of concentric carbon nanotubes but much larger, and with some of the chicken wire sheets broken up to leave gaps for the canals. But, Forró says, the authors’ data reveal that the chicken wire sheets are not as neatly arranged as the authors claim.

More research needs to be done, in particular to understand how the structures form and grow, admits the paper’s senior author, Quanxi Jia, of Los Alamos National Laboratory.

“What this paper does show,” says Otto Zhou of the University of North Carolina at Chapel Hill,” is that there are still a lot more new carbon materials to be discovered and explored."

Source

Corrugated carbon tubes/colossal carbon tubes (CCTs) - I wonder what their emission properties are. They are good electrical conductors!! Depends on the aspect ratio, of course - looks promising. ;-)

A Japanese company - FET - promises FED panel mass production by late 2009

Yoichiro Hata EE Times (08/06/2008 2:53 PM EDT) TOKYO — FE Technologies, a Japanese R&D firm spun out of Sony in 2006, announced that the company is poised to mass produce 26-inch FED panels by the end of 2009. The company is focused on the development of Field Emission Display (FED). Compared with other flat panel technologies such as LCDs and plasma displays, FED has long been known for its superior characteristics. They include: a higher contrast ratio, lower power consumption and wider viewing angle. Charles Spindt at Stanford Research Institute developed the principles of FED in 1968. Despite all of its advantages, FED has one big drawback: its manufacturability. Nobody has been able to mass produce FED as a video display, due to a number of technical issues. They include problems related to a structure of filed emitters and difficulty of attaining high vacuum levels required by FEDs. The Japanese company claims to have found solutions to the mass production problem. Principles of FE Technologies' FED Field emission displays are similar to CRTs. Instead of a single electron gun, FE Technologies' FED uses a large array of cone-shaped electrodes, called "Spindt." Many Spindts positioned behind each phosphor dot emit electrons through a process known as field emission. By charging 9kV electro differentials between anode and cathode substrates, electrons are generated and light up fluorescent material located in front of anode substrate. Electron generation is controlled by gate electrode. Spindt structure uses the field emission principle, which generates electron into air-vacuumed region at room temperature. There is no need for heating, said the company, as it leverages Tunnel effect. Self discharge between emitter and gate electrode is blocked by placing resistance layer. Conventional type of Spindt is structured by one Spindt per pixel. Therefore, size of each Spindt needs to be exactly identical. Otherwise, brightness of each pixel becomes uneven, thus lowering image quality. FE Technologies evened Spindt differentials by placing multiple numbers of Spindts, called Nano-Spindt Structure. "1,400 Spindts are required to keep pixel brightness differentials within 2 percent," said Hiroyuki Ikeda, general manager of marketing at F. E. Technologies. By implementing this structure, electric current per Spindt has decreased and life of Spindt itself has improved, according to the company. Sony spin-off FE Technologies was founded by investment from Sony and a few other companies. The mission of the company is to investigate FED business opportunity, said Shohei Hasegawa, FE Technologies President and C.E.O. "Idea of becoming independent was triggered by successful development of spacer materials," he explained. FED requires a high vacuum level. Spacer material which holds its shape between anode and cathode substrate against the air pressure is necessary. "We needed to develop electrically transparent material, which neither charges itself nor becomes conductive, but can maintain an electro field between anode and cathode " in parallel." In time for the FED panel mass production in late 2009, FE Technologies is scheduled to acquire Pioneer's Kagoshima plant before the end of 2008. The Japanese company will invest $183 million to $274 million (20 to 30 billion yen) in manufacturing equipment. FE Technologies will use the company's fourth generation glass substrate (730mm x 920mm). Each substrate will allow them to produce a pair of 26-inch panels. The company will proceed with the mass production of FED panels by using 5,000 glass substrates per month. The initial application for FE Technologies' 26-inch FED panels will be "master" monitors, used at TV broadcasting stations, to check picture quality. Neither LCDs nor PDPs are said to satisfy the high quality standard required by such master monitors. — Yoichiro Hata is managing editor of EE Times Japan. Source Does the Nano-Spindt Structure include CNTs? I do not know - perhaps - 1400 points per pixel is getting nano, indeed, and nothing is more nano than CNTs! We will have to see when they are sold whether they contain CNTs or not.

World's thinnest balloon made of graphene

Posted: August 6, 2008

(Nanowerk News) Researchers in New York are reporting development of the world's thinnest balloon, made of a single layer of graphite just one atom thick. This so-called graphene sealed microchamber is impermeable to even the tiniest airborne molecules, including helium. It has a range of applications in sensors, filters, and imaging of materials at the atomic level, they say in a study scheduled for the August 13 issue of ACS' Nano Letters ("Impermeable Atomic Membranes from Graphene Sheets").

A multi-layer graphene membrane that could be used in various applications, including filters and sensors (Image: Jonathan Alden)

Paul L. McEuen and colleagues note that membranes are fundamental components of a wide variety of physical, chemical and biological systems, found in everything from cellular compartments to mechanical pressure sensing. Graphene, a single layer of graphite, is the upper limit: A chemically stable and electrically conducting membrane just one atom thick. The researchers wanted to answer whether such an atomic membrane would be impermeable to gas molecules and easily incorporated into other devices.

Their data showed that graphene membranes were impermeable to even the smallest gas molecules. These results show that single atomic sheets can be integrated with microfabricated structures to create a new class of atomic scale membrane-based devices. We envision many applications for these graphene sealed microchambers, says McEuen. These range from hyper-sensitive pressure, light and chemical sensors to filters able to produce ultrapure solutions.

Source: National Science Foundation

Source

Nanomagnets tackle cancer

August 16th, 2008; Vol.174 #4

By Janet Raloff

August 16th, 2008; Vol.174 #4 (p. 5)

Technique uses heat to kill cancerous cells

FATAL ATTRACTION
In nanomagnetic cancer treatment, blue fluid with therapeutic nanomagnets targets tumor cells (right). But the nanomagnets leave healthy cells (left) alone. Click on image for full story.MagForce Nanotechnologies

A new wave of therapies can exert a magnetic hold over disease — literally. The therapies employ powerful, roughly spherical magnets to help kill carefully targeted diseased cells and nothing else. What makes these magnets special is their size. Each is about a thousandth the diameter of a human hair.

Most researchers in the field are designing these billionth-of-a-meter-scale magnets to serve as highly localized space heaters. Under the influence of an external magnetic field, the magnetic particles will warm to temperatures that will kill immediately adjacent cells.

Two U.S. research groups recently reported success in developing high-performance iron-cobalt nanomagnets for cancer therapy. New studies by another group describe the ability to target, track and deliver killer heat with a weaker, but potentially less toxic, class of cobalt-free magnetic nanoparticles.

If these nanonuggets and their ilk perform as expected, they should increase cancer survival rates and lower the toxicity associated with conventional therapies. Indeed, MagForce Nanotechnologies AG, based in Berlin, is exploring the idea of making its tiny magnetic beads do double duty: heat-treat tumors in the body and at the same time deliver drugs directly into malignancies. Direct delivery should largely eliminate the poisoning of healthy tissue — a primary side effect of most existing cancer treatments.

Some dozen teams around the world are developing these therapeutic beads, notes Robert Ivkov of Johns Hopkins University in Baltimore. He and others have established the technology’s proof of concept in test-tube and animal studies.

MagForce, the only group to have tested nanomagnet therapy in people, appears closest to commercialization. Over the past five years, it has conducted trials, enrolling patients with at least eight tumor types, according to Uwe Maschek, the company’s chief executive officer. The most advanced trial is currently studying some 65 patients with late-stage, recurrent glioblastoma multiforme, a type of brain cancer. Individuals with this cancer typically survive no more than seven months, he notes.

By next year the company hopes to establish whether its nanomagnetic therapy lengthens survival by at least three months. If it does, Maschek says MagForce could receive regulatory approval to market its technology in the European Union by the first quarter of 2010.

On June 2, Triton BioSystems Inc., Ivkov’s former employer, merged with another company to form Aduro Biotech, based in Berkeley, Calif. The new firm’s website describes a planned 2009 trial that would administer therapeutic nanomagnets to U.S. cancer patients.

MagForce founder Andreas Jordan began exploring nanomagnet cancer treatment some 20 years ago. He aimed to use hyperthermia — essentially inducing highly localized 44° Celsius to 50°C fevers to kill diseased tissue. Not only are cancer cells much more sensitive to heat, but radiation and cancer drugs also tend to work better on heat-stressed cells.

In fact, researchers have long been interested in using heat to treat disease. A research team at Presbyterian-St. Luke’s Hospital in Chicago led by R.K. Gilchrist reported a promising new approach — a full half century ago.

The surgeons injected a fine, iron-oxide powder into lymph nodes suspected of hosting metastases — the seeds of new cancers — and applied a magnetic field to heat the micromagnets. It worked like a charm, the researchers reported in a 1957 Annals of Surgery paper. “The possible application of such a tool,” Gilchrist’s group concluded, “requires little imagination.”

Yet the technology languished for much of the next four decades. Ivkov says it required something that was unusual in the 1950s — research teams that integrated chemists, materials scientists, cell biologists and physicists. Today such collective efforts tailor tinier and more effective magnets, and are perfecting strategies to activate the nanonuggets without burning healthy tissues along the way.

Nearly all research groups work with iron-oxide nanomagnets. But in the April 1 Journal of Applied Physics, Michael McHenry’s group at Carnegie Mellon University in Pittsburgh reported developing a non-oxide iron-cobalt particle with a magnetic strength five to 10 times that of oxide magnets. This could permit treatment using fewer magnetic nanoparticles, McHenry says, or a lower-powered external field to heat the nanobeads.

Ultimately, those beads will receive a coating to shield the potentially toxic cobalt and to keep the nanonuggets from looking like foreign objects that the body should mark for disposal. This coating can also be studded with antibodies to selectively bind to receptors found on the surface of a target, such as a cancer cell.

In a Journal of the American Chemical Society paper posted online in mid-July, Kenneth Scarberry and his colleagues at the Georgia Institute of Technology in Atlanta describe an oxide version of the iron-cobalt recipe for their nanobeads.

They gave their nanomagnets a “sugar coating” of polygalacturonic acid, Scarberry says, and then linked tiny proteinlike structures to the coating. The attached peptides serve as hooks to grab onto a receptor that’s only present on ovarian cancer cells.

The scientists report that by placing a big magnet on the skin of a treated mouse, they can pull injected nanobeads to the other side of the skin, which could facilitate eventual nanobead removal. But the application the researchers are most excited about, Scarberry says, is a dialysis-like system. It would pump liquids from inside the body through a tube outside the body. Nanomagnets treated with ovarian cancer cell “hooks” would line the inside of the tube. The beads would catch and hold passing metastatic cells, filtering the blood before it is returned to the body.

Scientists at the University of California, Davis School of Medicine and the former Triton BioSystems collaborated for several years on related studies using a different nanoparticle model. Instead of creating sugar-coated magnets, they essentially created sugar balls studded throughout with magnetic iron-oxide “raisins,” explains Ivkov.

His group attached antibodies that bind to receptors on breast cancer cells. Then they injected the nanomagnets into mice that had been seeded with those cancer cells and heated the beads for 20 minutes. Tumors in the treated animals shrank. Far more so, in fact, than predicted.

But cancer treatment is far from the only medical application being eyed for these nanomagnets. Scarberry first became interested in the technology a couple of years ago when he realized it might offer a clever adjunct to standard therapy for HIV — the AIDS virus. He won’t say much except that his preliminary data on this “look promising.”

Source

We all started out as diamonds in the rough, German scientists say

Posted : Mon, 04 Aug 2008 03:09:46 GMT Science Technology News

Hamburg - We all started out as diamonds in the rough - literally - according to German scientists who say crystalline interfacial water layers played a fundamental role in biology and evolution on planet Earth. These primordial pools of microscopic hydrogenated diamonds in the rough were the original soup from which all life sprang billions of years ago, say the scientists from the Institute of Micro and Nanomaterials at Ulm University in Germany.

When primitive molecules landed on the surface of these hydrogenated diamonds in the atmosphere of early Earth, the resulting reaction was sufficient to spawn the first complex organic molecules that eventually gave rise to life, the German scientists say. The diamonds, densely compressed carbon molecules, provided the structure needed to support organic molecules.

"The capacity of interfacial water layers to impose order was exposed in the process of formation of supercubane carbon nanocrystals," the Ulm scientists write in the current issue of the American Chemical Society's journal Crystal Growth & Design.

"It is important that the order imposed to molecules landing on hydrogenated diamond is more durable and superior to that realizable on any other origin of life platform, for instance, graphite. Hydrogenated diamond advances to the best of all possible origin of life.".

In lab experiments aimed to confirm work done more than three decades ago by other European researchers, German scientists Andrei Sommer, Dan Zhu, and Hans-Joerg Fecht at the University of Ulm, found that when treated with hydrogen, natural diamonds formed crystalline layers of water on the surface.

The German scientists noted that diamonds are crystallized forms of carbon that predate the oldest known life on the planet. Water is essential for life as we know it. All that was needed was an electrical spark, say, from a bolt of lightning.

"Origin-of-life models starting with a primordial soup work from two assumptions, which do not exclude each other: chemistry, which could trigger the self-assembly of abiotic organic compounds, and transfer of order from preexistent orderings," they wrote.

"Clearly, both organization processes must occur in a bio-relevant environment, that is, a wet milieu, and both are energy-consuming. Interestingly, a hostile planetary environment such as the primitive Earth, subject to rapid changes, including but not limited to volcanic and hydrothermal activity, acidic atmosphere, and virtually planet-sterilizing meteorite impacts, favours precisely the conditions necessary for the formation of first ordered structures, regarded as possible starting points of biological evolution.

"They concluded that natural diamonds are even more conducive to this life-spawning process than are synthetic diamonds.

"In our study the conductivity on natural diamond was better by a factor of 10 than that on synthetic diamond," they wrote. "We conclude that current ideas of surface-conducting diamond should be expanded to include the crystalline water layer.

"But the German scientists said their findings do not rule out the possibility that the first organic molecules arrived on Earth from outer space. This is the "panspermia" theory which claims that meteors plummeted to Earth from other places in the galaxy where life had already taken root.

"The emergence of bio-organic molecules under primitive Earth conditions is one of the major unsolved origin of life questions," the Ulm researchers said. "The principal problem is to identify physical and chemical conditions that are favourable for the formation of life precursor structures. Panspermia tries to circumvent the problem by assuming that primitive life forms, such as bacteria, have arrived on Earth from space, as star dust or via comets.

"Either way, of course, the evolution of life on Earth is something special. According to one theory, we are all stardust. According to the other theory, we are all diamonds.

Source

Solar-Power Breakthrough

Thursday, July 31, 2008

Researchers have found a cheap and easy way to store the energy made by solar power.

By Kevin Bullis

Splitting water: Daniel Nocera poses with a device for breaking down water into hydrogen and oxygen. The device uses an inexpensive catalyst that he has developed.
Credit: Donna Coveney, MIT

Multimedia video
Watch Daniel Nocera explain how his catalyst can be used to store sunlight.

Researchers have made a major advance in inorganic chemistry that could lead to a cheap way to store energy from the sun. In so doing, they have solved one of the key problems in making solar energy a dominant source of electricity.

Daniel Nocera, a professor of chemistry at MIT, has developed a catalyst that can generate oxygen from a glass of water by splitting water molecules. The reaction frees hydrogen ions to make hydrogen gas. The catalyst, which is easy and cheap to make, could be used to generate vast amounts of hydrogen using sunlight to power the reactions. The hydrogen can then be burned or run through a fuel cell to generate electricity whenever it's needed, including when the sun isn't shining.

Solar power is ultimately limited by the fact that the solar cells only produce their peak output for a few hours each day. The proposed solution of using sunlight to split water, storing solar energy in the form of hydrogen, hasn't been practical because the reaction required too much energy, and suitable catalysts were too expensive or used extremely rare materials. Nocera's catalyst clears the way for cheap and abundant water-splitting technologies.

Nocera's advance represents a key discovery in an effort by many chemical research groups to create artificial photosynthesis--mimicking how plants use sunlight to split water to make usable energy. "This discovery is simply groundbreaking," says Karsten Meyer, a professor of chemistry at Friedrich Alexander University, in Germany. "Nocera has probably put a lot of researchers out of business." For solar power, Meyer says, "this is probably the most important single discovery of the century."

The new catalyst marks a radical departure from earlier attempts. Researchers, including Nocera, have tried to design molecular catalysts in which the location of each atom is precisely known and the catalyst is made to last as long as possible. The new catalyst, however, is amorphous--it doesn't have a regular structure--and it's relatively unstable, breaking down as it does its work. But the catalyst is able to constantly repair itself, so it can continue working.

In his experimental system, Nocera immerses an indium tin oxide electrode in water mixed with cobalt and potassium phosphate. He applies a voltage to the electrode, and cobalt, potassium, and phosphate accumulate on the electrode, forming the catalyst. The catalyst oxidizes the water to form oxygen gas and free hydrogen ions. At another electrode, this one coated with a platinum catalyst, hydrogen ions form hydrogen gas. As it works, the cobalt-based catalyst breaks down, but cobalt and potassium phosphate in the solution soon re-form on the electrode, repairing the catalyst.

Source

2nd Article

By Thomas Claburn
InformationWeek

August 1, 2008 03:40 PM

Storing solar energy in batteries remains costly and inefficient. But that may not be true for much longer.

MIT researchers have discovered a way to store solar energy that could make solar power in homes a mainstream energy option and might even make power companies obsolete, at least for residential needs.

Daniel Nocera, a professor of chemistry and energy at MIT, and postdoctoral fellow Matthew Kanan have figured out how to split water into hydrogen and oxygen cheaply and efficiently at room temperature. The process can later be reversed, allowing the recombination of hydrogen and oxygen in a fuel cell to create carbon-free electricity.

"This is the nirvana of what we've been talking about for years," Nocera told the MIT News Service. "Solar power has always been a limited, far-off solution. Now we can seriously think about solar power as unlimited and soon."

Nocera's breakthrough could enable the "hydrogen economy," a possibility that many have dismissed as impractical.

Nocera told the MIT News Service that within 10 years, he expects that homeowners will be able to use solar power to provide electricity during the day and to store unused solar energy to power a household fuel cell for evening use. This would eliminate the need for electricity delivered over power lines.

According to the MIT News Service, James Barber, a professor of biochemistry at Imperial College in London, characterized the research by Nocera and Kanan as "a major discovery with enormous implications for the future prosperity of humankind."

Nocera and Kanan's research is described in an academic paper, "In Situ Formation of an Oxygen-Evolving Catalyst in Neutral Water Containing Phosphate and Co2+," that has just been published in Science magazine. [See below]

Source

Published Online July 31, 2008 Science DOI: 10.1126/science.1162018

Science Express Index

Reports

Submitted on June 19, 2008
Accepted on July 18, 2008

In Situ Formation of an Oxygen-Evolving Catalyst in Neutral Water Containing Phosphate and Co²⁺

Matthew W. Kanan ¹ and Daniel G. Nocera ^1*

¹ Department of Chemistry, 6-335, Massachusetts Institute of Technology, Cambridge, MA 02139–4307, USA.

^* To whom correspondence should be addressed.
Daniel G. Nocera , E-mail: nocera@mit.edu

The utilization of solar energy on a large scale requires its storage. In natural photosynthesis, energy from sunlight is used to rearrange the bonds of water to O₂ and H₂-equivalents. The realization of artificial systems that perform similar "water splitting" requires catalysts that produce O₂ from water without the need for excessive driving potentials. Here, we report such a catalyst that forms upon the oxidative polarization of an inert indium tin oxide electrode in phosphate-buffered water containing Co²⁺. A variety of analytical techniques indicates the presence of phosphate in an approximate 1:2 ratio with cobalt in this material. The pH dependence of the catalytic activity also implicates HPO₄^2– as the proton acceptor in the O₂-producing reaction. This catalyst not only forms in situ from earth-abundant materials but also operates in neutral water under ambient conditions.

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Nocera Podcast
(Next paper in a few months detailing a full system design with an alternative to Pt catalyst)