The panel will discuss the background and history of the roadmap, and explore how it will serve to help realize these horizons. The panelists are:

• Christine Peterson, Acting President of Foresight Nanotech Institute
• Dr. David Forrest, President of the Institute for Molecular Manufacturing and a Senior Fellow at the Foresight Nanotech Institute
• Dr. Pearl Chin, Research Fellow with Foresight Nanotech

For more information, see The Speculist: “Panel to Discuss Productive Nanosystems“
—Jim

…The potential payoffs of making proteins that don’t exist in nature, such as those needed for HIV vaccines or as catalysts for more-efficient biofuel production, are huge. But making proteins to meet a specific need can be difficult.

Now a leading protein researcher has teamed up with computer scientists to create an online game for developing useful protein structures. David Baker, a leading protein scientist at the University of Washington, says that players will help his lab design new vaccines and make enzymes for repairing DNA in diseased tissues.

…Baker recently demonstrated the first algorithm for building novel, functioning enzymes from scratch. But while proteins built from the ground up may have chemical properties unmatched by anything in nature, they aren’t particularly efficient.

The game, called Foldit, is part of Baker’s vision for the future of protein engineering. His algorithms are good at the nitty-gritty of generating completely novel protein sequences for a particular purpose. But humans, who are better at seeing the big picture than computers are, could improve computer-designed proteins by playing the game.

…Since 2005, Baker’s lab has relied on the computing power of Internet users who’ve installed a program that searches through protein designs. About 200,000 people around the world run his Rosetta@home program when their computers would otherwise be idle. As Rosetta@home runs, it displays the protein structures that it’s processing as a screen saver. Some users staring at the structures, which look like large tangles of multicolored string, told Baker that they could see how to make the structure better—where to tuck in a loose end, or how to pull the structure together tighter—but were frustrated because they had no way to provide input.

…The first several levels of Foldit are designed to teach players what good proteins look like and how to manipulate them using the tools of the game.

…After improving the designs of a few test proteins, players can advance into competitive play, working in teams or alone. Baker and [game designer Zoran] Popović have set players to work on proteins whose structures are known in order to refine the game and train a group of players. In time, players will be working on new HIV vaccines and Baker’s other projects.

…By making the game available to anyone over the Web, the researchers expect to find people they call protein savants—people who are very good at solving protein structures and who will spend several hours a week playing the game.

If you think you might be a protein savant, or would like to become one, you can download the Foldit game for free. Perhaps you will eventually get to work on a structure on the path to productive nanosystems.
—Jim

Fabrication technique could yield low-cost, scalable nanowire photonic and electronic circuits

Applied scientists at Harvard University in collaboration with researchers from the German universities of Jena, Gottingen, and Bremen, have developed a new technique for fabricating nanowire photonic and electronic integrated circuits that may one day be suitable for high-volume commercial production.

Spearheaded by graduate student Mariano Zimmler and Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering, both of Harvard’s School of Engineering and Applied Sciences (SEAS), and Prof. Carsten Ronning of the University of Jena, the findings will be published in Nano Letters [abstract]. The researchers have filed for U.S. patents covering their invention.

While semiconductor nanowires—rods with an approximate diameter of one-thousandth the width of a human hair—can be easily synthesized in large quantities using inexpensive chemical methods, reliable and controlled strategies for assembling them into functional circuits have posed a major challenge. By incorporating spin-on glass technology, used in Silicon integrated circuits manufacturing, and photolithography, transferring a circuit pattern onto a substrate with light, the team demonstrated a reproducible, high-volume, and low-cost fabrication method for integrating nanowire devices directly onto silicon.

“Because our fabrication technique is independent of the geometrical arrangement of the nanowires on the substrate, we envision further combining the process with one of the several methods already developed for the controlled placement and alignment of nanowires over large areas,” said Capasso. “We believe the marriage of these processes will soon provide the necessary control to enable integrated nanowire photonic circuits in a standard manufacturing setting.”

—Jim

Scientists at UC San Diego, UC Santa Barbara and MIT have developed nanometer-sized “nanoworms” that can cruise through the bloodstream without significant interference from the body’s immune defense system and—like tiny anti-cancer missiles—home in on tumors.

Their discovery, detailed in this week’s issue of the journal Advanced Materials [abstract], is reminiscent of the 1966 science fiction movie, the Fantastic Voyage, in which a submarine is shrunken to microscopic dimensions, then injected into the bloodstream to remove a blood clot from a diplomat’s brain.

Using nanoworms, doctors should eventually be able to target and reveal the location of developing tumors that are too small to detect by conventional methods. Carrying payloads targeted to specific features on tumors, these microscopic vehicles could also one day provide the means to more effectively deliver toxic anti-cancer drugs to these tumors in high concentrations without negatively impacting other parts of the body.

“Most nanoparticles are recognized by the body’s protective mechanisms, which capture and remove them from the bloodstream within a few minutes,” said Michael Sailor, a professor of chemistry and biochemistry at UC San Diego who headed the research team. “The reason these worms work so well is due to a combination of their shape and to a polymer coating on their surfaces that allows the nanoworms to evade these natural elimination processes. As a result, our nanoworms can circulate in the body of a mouse for many hours.”

…The scientists constructed their nanoworms from spherical iron oxide nanoparticles that join together, like segments of an earthworm, to produce tiny gummy worm-like structures about 30 nanometers long—or about 3 million times smaller than an earthworm. Their iron-oxide composition allows the nanoworms to show up brightly in diagnostic devices, specifically the MRI, or magnetic resonance imaging, machines that are used to find tumors.

…In addition to the polymer coating, which is derived from the biopolymer dextran, the scientists coated their nanoworms with a tumor-specific targeting molecule, a peptide called F3, developed in the laboratory of Erkki Ruoslahti, a cell biologist and professor at the Burnham Institute for Medical Research at UC Santa Barbara. This peptide allows the nanoworms to target and home in on tumors.

“Because of its elongated shape, the nanoworm can carry many F3 molecules that can simultaneously bind to the tumor surface,” said Sailor. “And this cooperative effect significantly improves the ability of the nanoworm to attach to a tumor.”

—Jim

A new technique in paint making could soon make almost any surface germ-free. Researchers have made paint that is embedded with silver nanoparticles, known for their ability to kill bacteria and other microbes, in the hopes that hospitals will coat their walls and countertops to fight infection.

According to the U.S. Centers for Disease Control and Prevention, more than 1 million people per year contract bacterial infections in hospitals. Silver itself is an excellent bacteria fighter, and in nanoparticle form it is even more potent at killing microorganisms. So far it has not shown any adverse effects in humans.

However, some scientists are concerned that silver nanoparticles may not be as harmless as they appear. Little research has been done on their health and environmental effects, and silver kills good microorganisms along with the bad. Also, there are currently no restrictions on using silver nanoparticles, which are already popping up in a range of consumer products that tout their antibacterial properties.

“Nanoparticles are very small and they are interacting with the bacteria and rupturing the cell wall,” says chemist George John of City College of New York and lead author of the study, published in the journal Nature Materials [abstract] last month. This rupturing kills the bacteria, he explains.

A silver nanoparticle is a small cluster of silver atoms less than 100 nanometers, or 100 billionths of a meter, wide. Because of their size, nanoparticles exhibit different properties than their bulkier counterparts. They have a high surface area to volume ratio, which makes them able to dissolve in paint. Nanoparticles are also being studied for their use in medicine, particularly in drug delivery, since they are able to pass easily through cell membranes.

…”It is more or less like a soaping or detergent effect,” says Lucian Lucia, associate professor of chemistry at North Carolina State University. The nanoparticle destroys the cell wall of the microbe.

Lucia and John both agree that bacteria cannot build up a resistance to silver nanoparticles as they can to antibiotics, because of the way the silver nanoparticle attacks — destroying the structure of the cells and killing them. Antibiotics, on the other hand, suppress the activity of bacteria but don’t necessarily kill them. “That’s the beauty of silver,” Lucia says. “There’s no way to develop a resistance to it.”

…Andrew Maynard, the chief science advisor for the Project on Emerging Nanotechnologies, funded by the Woodrow Wilson International Center for Scholars and the Pew Charitable Trust, is … concerned about the lack of research and regulation on the use of silver nanoparticles. He says this technology is cropping up in unlikely products, like socks, kitchenware and cosmetics, to name a few.

“You have an anti-microbial agent appearing everywhere, including children’s fluffy toys, with no knowledge about its health or environmental implications,” Maynard says. “What are the chances of it taking out an ecologically important bacteria?”

And it is this question that Maynard wants answered before the technology is applied to any more commercial products. On the other hand though, Maynard acknowledges that the use of silver nanoparticles holds promise, particularly in hospital settings.

—Jim

He sent the URL for notes on interests and concerns from the human enhancement policy discussions: http://www4.ncsu.edu/~pwhmds/notes.html
and the final reports: http://www4.ncsu.edu/~pwhmds/final_reports.html

Stuart commented:

I thought that Arizona’s was one of the better and that Wisconson and New Hampshire were about as expected. What, if any, impact they will have is open to speculation. From the response the project operators made, this technique might be used more in the future. It was a part of the experiment as well as the topic.

If you have thoughts on the process or reports, we’d like to hear them. Just comment on this blog post. —Christine

…Rather than perfecting a nanostructure by improving its original fabrication method, researchers at Princeton University have demonstrated a new method, known as self-perfection by liquefaction (SPEL), which removes nanostructure fabrication defects and improves nanostructures after fabrication.

“When feature sizes in a device are small enough, the fabrication defects in many nanofabrication methods can become a dominant factor that determines the actual shape of the nanostructure” Dr. Stephen Y. Chou explains to Nanowerk. “Although extrinsic defects can be removed by improving the process, intrinsic defects caused by the fundamental statistical nature of a fabrication process — for example, noise in photon, electron or ion generation, scattering, and variations in chemical reaction — cannot be removed within the process regardless of improvements to it. The minimum line width and line height are often determined by the fundamental working principle of a fabrication, and are fixed once a fabrication method is selected.”

“Our process removes defects after fabrication rather than in the fabrication. As structures become very small, conventional fabrications will be limited by intrinsic noise, and improving the fabrication technology becomes fruitless.”

Chou, the Joseph C. Elgin Professor of Engineering at Princeton University and head of the university’s Nanostructures Laboratory, developed the method along with graduate student Qiangfei Xia. Chou’s lab has previously pioneered a number of innovative chip making techniques, including a revolutionary method for imprinting of nanopatterns on wafers. The scientists published their method in the May 4 online issue of Nature Nanotechnology (”Improved nanofabrication through guided transient liquefaction“), showing a technique that could lead to more precise shaping of microchip components beyond the current technology limits, potentially allowing them to be smaller, better and more powerful computers and other devices.

“SPEL is a paradigm shift in nanofabrication,” says Chou. “We are able achieve a precision far beyond what was previously thought possible (e.g. ITRS – The International Technology Roadmap for Semiconductors). Using this method we reduced the line-edge roughness of 70-nm-wide chromium grating lines from 8.4 nm to less than 1.5 nm, which is well below the ‘red-zone limit’ of 3 nm discussed in ITRS. We also reduced the width of a silicon line from 285 nm to 175 nm, while increasing its height from 50 nm to 90 nm.”

—Jim

Current topics to edit in the wiki, or you can add your own:
* Barless Prisons
* Bionic Eyes
* Living with a Brain Chip
* Disease Detector
* Automated Sewer Surveillance
* Engineered Tissues

Here’s the text sent to us by the Center:

The Center for Nanotechnology in Society at Arizona State University (CNS-ASU) invites you to help design the future of nanotechnology.

READ, REVISE, RANT: Some say that Nanotechnology will revolutionize life as we know it, but what should we really expect from the future of nanotechnology? CNS developed 6 plausible product descriptions- called scenes- to provide some structure to discussions about nanotechnology. These fictional scenes have been evaluated by nanoscale scientists and engineers for technical plausibility- it is up to you to weigh social, economic, ethical, environmental and political plausibility—and desirability!!

Through an interactive website, the NanoFutures experiment invites citizens, scientists and engineers, social scientists, policy makers, and others interested in nanotechnology to assess the potentials and perils of nano-enabled futures. On this site you can:

READ the scenes: What if ultra fast sequencing technology is used to analyze the DNA in harvested waste water? What if you could predict disease before the onset of symptoms? What if your intelligence was enhanced with a brain chip? What if, instead of prisons, convicted criminals were injected with disabling drugs that were activated if the prisoners misbehaved?

REVISE the scenes in a wiki: the scenes are predominately technical- what about social values, religious viewpoints, economic feasibility, and ethical desirability? Edit the scenes to create richer portraits of the implications of the technology.

You can also write your own scenario about nanotechnologies’ development!

RANT about and discuss the scenes: What are your thoughts on the implications of nanotechnology? Are there some technologies that should not be developed? Who should control nanotechnology?

Go to: http://cns.asu.edu/nanofutures

TAKE 30 MINUTES OF YOUR TIME NOW TO HELP CREATE THE NANOFUTURE!!

Researchers at Purdue University have discovered a possible new pathway for anti-tumor drugs to kill cancer cells and proposed how to improve the design of tiny drug-delivery particles for use in “nanomedicine.”

The synthetic “polymer micelles” are drug-delivery spheres 60-100 nanometers in diameter, or roughly 100 times smaller than a red blood cell. The spheres harbor drugs in their inner core and contain an outer shell made of a material called polyethylene glycol.

Purdue researchers showed for the first time how this shell of polyethylene glycol latches onto the membranes of cancer cells, allowing fluorescent probes mimicking cancer drugs to enter the cancer cells, said Ji-Xin Cheng, an assistant professor in the Weldon School of Biomedical Engineering and Department of Chemistry.

…New findings are detailed in two research papers. One paper appears this week in Proceedings of the National Academy of Sciences [abstract], and another paper also will appear in May in the journal Langmuir [abstract].

The researchers used an imaging technique called Förster resonance energy transfer imaging, or FRET, to make two key discoveries: how fluorescent molecules mimicking the cancer drug paclitaxel enter tumor cells and how the micelles break down in the blood before they have a chance to deliver the drug to cancer cells.

A critical feature of micelles is that they combine two types of polymers, one being hydrophobic and the other hydrophilic, meaning they are either unable or able to mix with water. The hydrophobic core was loaded with a green dye and the hydrophilic portion labeled with a red dye.

Experiments showed that “core-loaded” fluorescent molecules mimicking the drug entered cancer cells within 15 minutes, suggesting a new drug-delivery pathway to kill tumor cells, Cheng said.

…”So this technique provides a system to monitor in real time how well anti-cancer drug delivery is working,” Cheng said.

—Jim

A model system that could serve as a “blueprint” for graphene-based nanodevices of the future has been put forward by scientists in Italy, Turkey and Germany. The model involves using alternating chains of boron clusters to connect various parts of a semiconducting graphene substrate. The concept is very similar to that routinely employed in silicon-based integrated circuits, but the resulting graphene-based devices would be several orders of magnitude smaller.

Graphene is set to become one of the key materials in future nanotechnology applications. However, graphene-based devices studied so far are on the micron rather than nanoscale because they mainly consist of broad sheets of graphene connected by wiring of about the same size.

Now, Jens Kunstmann of the Max-Planck Institute for Festkörperforschung in Stuttgart and colleagues have proposed a way to take the wiring down to the nanoscale by implanting chains of B7 clusters into the graphene matrix. These clusters might then be used to connect various areas of a semiconducting graphene substrate.

Previous theoretical studies on heterogeneous nanotubular boron-carbon networks by the team have shown that boron and carbon are compatible on the nanoscale. The researchers have gone a step further and calculated that small planar boron clusters embedded into a graphene substrate act as metallic islands. These functionalize the surrounding graphene to allow electron transport through the substrate.

The research paper “Functionalizing graphene by embedded boron clusters” is available at arXiv.org.
—Jim