The National Cancer Institute’s Alliance for Nanotechnology in Cancer describes a significant advance toward personalized nanotech treatments for cancer. The effectiveness of treatment with multifunctional nanoparticles was studied using human breast tumors grown in rats lacking an immune system (to prevent the rats rejecting the foreign tumors) so that the variation in the effectiveness of treatment could be compared among individual breast tumors. From “Nanoparticle reports on drug delivery to breast tumors, predicts response to therapy“

One of the hallmarks of many nanoparticle-based anticancer therapeutics and imaging agents is that they accumulate in tumors thanks to the fact that they are small enough to escape from the bloodstream through the leaky blood vessels that surround tumors. And although many if not most tumors are surrounded by leaky blood vessels, the extent of that leakiness varies widely among tumors. As a result, the effectiveness of a given nanoparticle-based therapeutic also might vary from patient to patient in a way that is now impossible to predict.

A research team headed by Ravi Bellamkonda, Ph.D., the Georgia Institute of Technology, appears to have hit on a solution to the problem of determining how much of a nanoparticle drug is actually making it into breast tumors. The team’s approach, which is described in a paper in the journal Biomaterials [abstract], involves adding an approved x-ray contrast agent to a drug-loaded nanoparticle and then using standard mammography to quantify how much of the nanoparticle accumulates in a particular breast tumor. These results hold promise for personalizing breast cancer therapy.

…When the researchers monitored the nanoparticles for 3 days after injection, they observed that there was wide variability in the amount of nanoparticle that they could observe in different tumors. Some tumors rapidly accumulated significant levels of the nanoparticle, whereas other tumors showed a slow and low uptake. More importantly, the investigators noted that those animals that showed rapid uptake of the nanoparticles, as visualized using mammography 3 days after dosing, survived significantly longer than did those animals with a slower uptake.

One way to compensate for variations in capillary permeability in different tumors might be to decorate nanoparticles with molecules that specifically target tumor cells, as in this post from last week.
—Jim

In an interesting coincidence and counterpoint to Jim’s Nanophobia post this morning, I ran across the following on Nature News:
Fearing the fear of nanotechnology. It is, surprisingly perhaps, by our old friend Richard Jones. The thrust of the article is that a study in Nature Nanotechnology seems to show that the public’s reaction to nanotech is not as simplistic as technologists seem to think it is, and that there’s a significant segment that recognizes nanotech’s promise and broadly expects benefits to outweigh risks.

All too often, scientists treat the public as an undifferentiated mass. Indeed, sociologist of science Arie Rip, of the University of Twente in The Netherlands, goes so far as to identify widespread ‘nanophobia-phobia’ among nanotechnology insiders — an unreasonable and exaggerated conviction that a scientifically illiterate public with no appreciation of how to balance risks will reject a promising technology at the behest of an irresponsible media.
A more sophisticated analysis must recognize that the public is made up of different people with their own ideologies, through which they filter information about technologies and their risks.
Perhaps the most common of scientists’ preconceptions is the idea that fear of technology arises from ignorance, and that public acceptance inevitably grows as people learn more about the technology. Dan Kahan of Yale Law School in New Haven, Connecticut, and colleagues call this the familiarity hypothesis, and have now shown that it is not true.
People’s views of nanotechnology can become more or less favourable as they learn more, the authors found, depending on their ideological starting point. So-called hierarchical individualists, who like free markets and respect the authority of social elites, find more to approve of in nanotechnology as they grow more familiar with it. Conversely, more information seems to give ‘egalitarian communitarians’ more to be concerned about.

In this connection, it seems that there is an important role for Foresight — to maintain a strong emphasis on the difference between eutactic, atomically precise manufacturing and the kind of “nanotechnology” that involves the application of uncontained nanoparticles.

–Josh

The New York Times brings an article by Natasha Singer that sums up the ambiguous status of nanotech in consumer products, particularly cosmetic and personal care products, and the also ambiguous attitudes about nanotechnology. It is not clear that there is any real danger from the nanotech products currently in use, but neither is there convincing proof that all are safe. Each nanomaterial and each nanotech product needs to be judged individually, but it is worrisome, although not unexpected, that thorough research night sometimes be trumped by commercial convenience. It seems crucial for the development of nanotechnology as a component of commercial enterprises that ambiguity be replaced by clear standards arising from sufficient research. From “New Products Bring Side Effect: Nanophobia“:

IT sounds like a plot straight out of a science-fiction novel by Michael Crichton. Toiletry companies formulate new cutting-edge creams and lotions that contain tiny components designed to work more effectively. But those minuscule building blocks have an unexpected drawback: the ability to penetrate the skin, swarm through the body and overwhelm organs like the liver.

Humans have long lived in dread of such nightmare scenarios in which swarms of creatures attack. Alfred Hitchcock envisioned menacing flocks in “The Birds.” In the 1990 film “Arachnophobia” a killer spider arrives in the United States, where it attacks and multiplies.

And now comes nanophobia, the fear that tiny components engineered on the nanoscale — that is, 100 nanometers or less — could run amok inside the body. A human hair, for example, is 50,000 to 100,000 nanometers in diameter. A nanoparticle of titanium dioxide in a sunscreen could be as small as 15 nanometers. (One nanometer equals a billionth of a meter.)

“The smaller a particle, the further it can travel through tissue, along airways or in blood vessels,” said Dr. Adnan Nasir, a clinical assistant professor of dermatology at the University of North Carolina at Chapel Hill. “Especially if the nanoparticles are indestructible and accumulate and are not metabolized, if you accumulate them in the organs, the organs could fail.”

Indeed, some doctors, scientists and consumer advocates are concerned that many industries are adopting nanotechnology ahead of studies that would establish whether regular ingestion, inhalation or dermal penetration of these particles constitute a health or environmental hazard. Personal care products are simply the lowest hanging fruit.

—Jim

Josh Hall, author of Nanofuture: What’s Next for Nanotechnology, sends this message to Nanodot readers:

Dear Foresight members & friends,

It’s the time of year when many of you are renewing your Foresight memberships, and helping us meet our $30,000 goal for our Challenge Grant by December 31:
http://www.foresight.org/challenge

I believe that the next decade or two will be the period when nanotechnology and AI, along with some of the other technologies of the kind Foresight was founded to watch, really begin to have major effects on the world outside the labs. Here are some thoughts on the subject (this essay is also posted on Nanodot). We hope to expand and deepen the analysis here over the coming year, and we hope you can be a part of it.

Foresight — with Peripheral Vision

Back in the 60s, Marvin Minsky, John McCarthy, and others presided over
a burgeoning field of study, Artificial Intelligence. Using machines that were
pitifully small and underpowered by today’s standards, they made remarkable
strides toward a visionary goal: creating a machine that could think and converse
like a human being.

Then an unfortunate thing happened. In the 70s, the amount of money
going to AI research began to attract political attention, as money will do.
The people not getting the money used political skills to have it redistributed.
The result was that funding shifted from the core of AI to applications — in
fact, the infamous Kefauver Amendment made it illegal for ARPA to fund any
basic research at all! The decade of the 80s was seen as the decade of the
expert system, where techniques developed in AI were used to tackle real-world
problems — but within the field, it was known as “the AI winter.”

What had happened was that in the shift to applications, work shifted to
concerns that were peripheral to the key elements of the original vision. A
machine that plays a good game of chess is not necessarily intelligent. We call
a good human chess player intelligent because the human learned the game by
watching, imitating, modeling, and in general building up a skill. The machine
got the skill by having human programmers figure it out and build it in. It’s the
ability to learn and build skills that constitutes intelligence, not simply having
them. And AI had shifted to be largely a field which built skills directly, instead
of one which studied how to build a machine that could learn them.

Does this sound familiar? It’s essentially the same thing that happened to
nanotechnology two decades later. The core of the generative vision — productive
machinery built to atomic precision — fell out of favor, and was even attacked
by the people who thought they could, or at least claimed they could, produce
the same results by short-circuiting the process.

But of course in both cases the result is something evolutionary instead of
revolutionary. And in both cases, perhaps surprisingly, the missing element is
the same: autogeny.

Walk into any consumer electronics store and you can buy a GPS unit that
would have flabbergasted any AI researcher in the 60s. It knows the map of the
whole continent. It can plan routes, estimate times, and plot your course while
you drive, about as well as a good human navigator — the errors are different
but comparable. It speaks to you in English, and you can speak to it and, for a
limited set of commands, it understands. The GPS seems a tour de force of the
kind of capabilities AIers were trying to build, and it is a damned useful gadget.
But having a GPS won’t help you one single bit when you try to build the next
“AI” device. Neither will a chess-playing program or house-cleaning robot.

Similarly, the products of current-day “nanotechnology” are beginning to
approach, in some respects, some of the possibilities pointed out by Feynman and
Drexler. The density of memory and circuitry is rapidly approaching molecular
scale. An iPod can hold the text of ten tons of books. New materials are being
fabricated whose properties will likely enable single-stage-to-orbit spacecraft.
But while both are damned useful gadgets, neither is going to help you build a
cell repair machine.

But evolutionary advance, along with general scientific and technological
progress, ultimately lays the groundwork for enough new capabilities for
autogenous systems to be built. One can’t be certain, and wishcasting is always a
pitfall to guard against, but there seems to be some movement back to the
center. In AI, Marvin Minsky could say “AI has been brain-dead since the 70s” and
then be invited to keynote the leading AI conference. Ben Goertzel, originator
of the term “artificial general intelligence” and leading proponent of a return to
AI’s roots, reports that he is no longer laughed off the stage at mainstream AI
meetings. There is a AAAI-sanctioned AGI conference series now going in to
its second year.

In nanotechnology, the cracks in the glass ceiling are appearing in the form
of the Battelle/Foresight Roadmap for Productive Nanosystems and some grant
funding for mechanosynthesis work.

I’ll go out on a limb and say I expect the loop to close in AI sometime in the
next decade and in nanotech in the decade after that. The world will become
an interesting place. To foresee with even a cloudy lens, we need to look at
a variety of technologies that could support an autogenous feedback loop and
thus have a revolutionary impact. Here are some candidates:

• Biotech is already built on an autogenous base, the reproductive capacity
of life.

• Software likewise is a substrate capable of supporting autogeny at a
number of levels short of true AI. The intersection of software, datacomm, and
human-based memetics over the past couple of decades has been explosive.

• Robotics: replacing human workers in physical factories, particularly ones
that made humanoid worker robots, would take humans out of the productive
loop, enabling a takeoff.

• Desktop fabricators: the same idea in a smaller package. I expect the
2010s to be a decade of experimentation with them the way the 80s were
for PCs. There seems to be a fairly straightforward path from fabs to
nanofactories, with increased value added at each stage.

The convergence of these, along with AI and nanotech and who knows how
many others I haven’t thought of, will form the core of technological capability
in the twenty-first century. I suspect that a study of the properties of general
autogenous systems will be invaluable in understanding it.

Once this takes hold, virtually everything will begin changing at Moore’s
Law rates. Let’s hope we have enough foresight that the changes will be
improvements.

————————————————————————

Comments are welcome — you can email me at josh@foresight.org, or go to our blog Nanodot (http://foresight.org/nanodot) and respond in the comments field for “Foresight — with Peripheral Vision.”

Please, if you can, chip in on the Challenge Grant at http://www.foresight.org/challenge. Every dollar you donate will be automatically doubled, so Foresight can do twice as much to influence our future in the positive direction that we all hope for.

Josh Hall
josh@foresight.org

Foresight Institute
1455 Adams Drive, Suite 2160
Menlo Park, CA 94025 USA
Tel +1.650.289.0860
Fax +1.650.289.0863

A nanotech technique that can coat any number of common fabrics with a layer of silicone nanofilaments appears ready to produce durable, completely waterproof clothing. From News Scientist, written by Jon Evans “Nanotech clothing fabric ‘never gets wet’“:

If you were to soak even your best raincoat underwater for two months it would be wet through at the end of the experience. But a new waterproof material developed by Swiss chemists would be as dry as the day it went in.

Lead researcher Stefan Seeger at the University of Zurich says the fabric, made from polyester fibres coated with millions of tiny silicone filaments, is the most water-repellent clothing-appropriate material ever created.

Drops of water stay as spherical balls on top of the fabric … and a sheet of the material need only be tilted by 2 degrees from horizontal for them to roll off like marbles. A jet of water bounces off the fabric without leaving a trace ….

The secret to this incredible water resistance is the layer of silicone nanofilaments, which are highly chemically hydrophobic. The spiky structure of the 40-nanometre-wide filaments strengthens that effect, to create a coating that prevents water droplets from soaking through the coating to the polyester fibres underneath.

“The combination of the hydrophobic surface chemistry and the nanostructure of the coating results in the super-hydrophobic effect,” Seeger explained to New Scientist. “The water comes to rest on the top of the nanofilaments like a fakir sitting on a bed of nails,” he says.

The research was published in Advanced Functional Materials [abstract]
—Jim

Michael Berger at Nanowerk has compared the centralized strategy of Russia’s new nanotechnology program with the national nanotech strategies of other countries. From “Russia’s nanotechnology crash program“:

This week’s successful international nanotechnology forum Rusnanotech in Moscow has put a spotlight on Russia’s ambitions to catch up with the leading nanotechnology nations. While Russia has the money, the political will, and a well educated scientific base to be a leading player, it has completely missed the boat on developing its nanoscience programs and nanotechnology infrastructure.

In terms of gross domestic product (GDP), Russia ranks as the eleventh largest economy in the world. But while many smaller countries such as Australia or South Korea, not to mention all of the bigger nations, have invested steadily and broadly in all areas of nanosciences and nanotechnologies for years now, Russia has had no coordinated science policy, no industrial policy, and no commercial industrial base to develop its nanotechnology capabilities. Until last year, that is. In April 2007, the Russian president signed off on a public policy paper that ordered a multi-billion dollar program to develop a world-class Russian nanotechnology industry by 2015.

After describing the Russian program in some detail, Berger concludes:

It is obvious that Russia has chosen a much more centralized approach to developing a nanotechnology industry than most other industrial nations. While this could be a result of the countries past history of large state monopolies, it could on the other hand be the only realistic way of pulling off the crash development of the Russian nanoindustry.

…Time will show if the Russian approach works. With the flurry of deals, projects and cooperations announced over the past few months, not to mention the glitzy Rusnanotech event, they appear to be off to a good start.

—Jim

Nanowires that are superconducting above liquid nitrogen temperature have been produced for the first time, and their properties vary according to the diameter of the nanowires. The fact that they are superconducting over wider temperature ranges than other nanowires may make them uniquely suitable for some nanotech applications. From Laura Mgrdichian at PhysOrg.com “High-Temp Superconducting Nanowire System is First of its Kind“:

Scientists from the California Institute of Technology have, for the first time, created an array of nanowires that are superconducting at relatively high temperatures. This work, published recently in Nano Letters [abstract], could lead to the incorporation of superconducting nanowires into emerging nanotechnologies.

Researchers around the world have been working to create superconducting nanowires, but few studies have investigated the feasibility of nanowires made of high-critical-temperature (high-Tc) superconducting materials and, prior to this work, no such nanowires had been produced.

“We did not know whether high-Tc superconductivity could be maintained for very long, thin nanowires or whether their behavior would follow traditional superconductor models,” said CalTech chemist James Heath [one of the winners of the 2000 Foresight Nanotech Institute Feynman Prize in the Experimental category], the paper’s corresponding author, to PhysOrg.com.

He added, “High-Tc materials as nanostructures are also notoriously difficult to fabricate because their crystal structure and other properties must be maintained, and this is not easy to do.”

High-Tc materials are often more desirable than traditional superconductors because they function at temperatures “warmer” than the boiling point of liquid nitrogen, or 77 degrees Kelvin (about -321 degrees Fahrenheit). While still ultra-cold by everyday standards, these temperatures are easier to achieve in the laboratory because liquid nitrogen, which is commercially available and relatively easy to work with, can be used to cool them. This makes high-Tc materials more suitable for many applications.

—Jim

Using a nanotech drug delivery method to target cancer cells is much more effective than using the drug by itself. In laboratory tests, nanoparticles that include a small molecule of nucleic acid that binds to a target molecule on prostate cancer cells were used to carry a lethal dose of the drug into the cancer cells without affecting cells lacking the cancer-specific target. From the National Cancer Institute’s Alliance for Nanotechnology in Cancer “Targeted Nanoparticles Boost Platinum-Based Anticancer Therapy“:

A research team from the Massachusetts Institute of Technology (MIT)-Harvard Center for Nanotechnology Excellence has custom-designed nanoparticles that can deliver the anticancer drug cisplatin specifically to prostate cancer cells. The nanoparticles are composed of two different polymers and are decorated with a nucleic acid aptamer that binds to the tumor marker prostate-specific membrane antigen. This aptamer ensures that the nanoparticles deliver their payload only to prostate cancer cells.

Stephen Lippard, Ph.D., and Robert Langer, Ph.D., MIT, and Omid Farokhzad, M.D., Harvard Medical School, led the team that developed this new formation of cisplatin. The investigators published their results in the Proceedings of the National Academy of Sciences of the United States of America [abstract].

To construct a stable nanoparticle that would only release its toxic cargo inside tumor cells, the investigators synthesized a modified version of cisplatin that includes a long hydrocarbon chain. As the nanoparticle forms, the hydrocarbon chain associates strongly with the hydrophobic chains of the polymer that forms the nanoparticle’s core. The researchers note that the hydrocarbon chain they chose optimizes both drug encapsulation and drug release inside tumor cells. Once the nanoparticle enters the cell, the modified drug is converted into its active form as a result of chemical conditions inside the cell.

Tests with human cancer cells growing in culture showed that these nanoparticles were taken up specifically by tumor cells and not by healthy cells. Nanoparticles lacking the targeting aptamer were not taken up either. These tests also demonstrated that the nanoparticles release their cargo over the course of 60 hours, providing a sustained lethal level of the drug inside the targeted cells. In addition, the nanoparticle formulation was approximately 100 times more effective at killing tumor cells than was cisplatin by itself.

—Jim

It is with great sadness that we report the death of Prof. Arthur Kantrowitz, a founding Advisor of Foresight Institute and an early supporter of molecular nanotechnology concepts when they were first developed at MIT in the late 1970s by then-student K. Eric Drexler.

Arthur was an amazingly innovative scientist and technologist, as described in his Wikipedia entry, which is worth reading. The fact forums described in Engines of Creation were an extension of Arthur’s Science Court concept.

To be inspired, read his essay The Weapon of Openness which guides Foresight’s work today, especially in the area of Open Source Sensing. We’ll miss his wisdom.

It’s hard to say goodbye to this wonderful long-time friend. —Chris Peterson

A nanostructure called a “gyroid” self-assembled from diblock copolymers provides a scaffold with the proper dimensions so that when light knocks electrons loose from a dye molecule, the electrons and the holes left behind can be separated to obtain an electric current, providing the basis for a more efficient, inexpensive nanotech solar cell. PhysOrg.com points us to this Cornell University news article by Bill Steele, “Nanomanufactured polymer film could lead to lower-cost solar cells“:

You never know where basic research may lead. For decades materials scientists have been experimenting with a corkscrew-like polymer structure called a gyroid. Now an international team of researchers has shown that the gyroid structure can be used to “self-assemble” a low-cost photovoltaic cell.

The idea could lead to more economical solar collectors and more efficient fuel cells.

The prototype is a variation on the Graetzel solar cell, which uses an organic dye sandwiched between two conductors. Forming the conductors into an interlocking corkscrew allows current to be transported out efficiently. The team’s first cell, made in a thin film 400 nanometers thick, has a conversion efficiency ranging from 0.7 to 1.7 percent — low compared with silicon-based photocells, but “amazing” for such a thin film, said Ulrich Wiesner, the Spencer T. Olin Professor of Materials Science and Engineering at Cornell.

“The next step is to make it thicker” so more of the light falling on it can be captured, he said. “We hope that we will eventually get efficiencies that rival silicon-based devices.” Currently available silicon-based solar cells convert about 15 percent of the energy of the light falling on them to electricity, although some new designs promise higher efficiencies.

The work by Wiesner and scientists at the Universities of Cambridge and Oxford in Britain, the Freiburg Institute for Advanced Studies in Germany, Institute Curie in France and the University of Minnesota, Minneapolis, is described in the online version of the journal Nano Letters [abstract] ….

…the researchers assembled a copolymer gyroid film, then dissolved away just the corkscrew part of the structure, leaving a corkscrew-shaped mold that they filled with titanium oxide. Heating then burned off the other polymer part and crystallized the titanium oxide into a solid structure that conducts electrons. This was coated with a light-sensitive dye, and finally the space around it was filled with a material that conducts “holes” (positive charges).

When light strikes the dye it knocks loose electrons, which flow into the titanium oxide framework, while the holes left behind flow into the other conductor. Electrodes above and below the film carry off the resulting current.

The secret of a solar cell, Wiesner explained, is that the electron-hole pairs must find the interface between the two conductors within 10 nanometers (about the width of 30 atoms) so they can separate and flow away, or they will recombine.

“This is why block copolymers are exciting,” Wiesner said, “because that is the characteristic length scale of separation of the two blocks.”

—Jim