Responsible Nanotechnology

Off-Topic But Cool

RNA interference, or RNAi, is a technique that cells use to fight off viruses. Some viruses store their genetic material in the form of RNA, and as the virus replicates in a cell, small doubled-over fragments of the virus's RNA are produced. A folded-over strand of RNA floating inside a cell indicates that that cell is infected, and the strand is part of the virus's genome. So the cell will try to suppress viral replication by suppressing any protein manufacture which uses that sequence.

Although RNAi was discovered only recently, scientists recognized that it could provide a new way to control which genes are expressed in a cell. Simply make an RNA fragment that contains part of the gene you want to knock out, introduce it to the cell, and the cell will shut down its own production of the corresponding protein just as though the RNA fragment had come from a virus.

Now it turns out that viruses have beaten us to this trick. The Epstein-Barr virus is a DNA virus, presumably more highly evolved than RNA viruses. But it contains five genes that produce double-stranded RNA, and these strands switch off expression of certain genes in the host cell. Guess what -- these genes appear to be ones that would help the cell respond to the virus. And guess what else -- the list includes the tumor-fighting gene p53. This could explain how this virus can promote certain cancers.

A virus turning a cell's anti-virus mechanism against itself -- what won't nature think up next?

Chris Phoenix

Journalism Gone Wrong

A few years ago, Scientific American published an article that began with the words, "That's the messiah," and proceeded to inform us that Eric Drexler sounded like Mr. Peabody. This, we assume, was because they had nothing more substantial to say, but for some reason felt a pressing need to oppose Drexler's work on molecular manufacturing. The article was so bad that it evoked a strong protest from Carl Feynman, son of the Nobel-winning physicist Richard Feynman, about their abuse of his father's name and reputation.

Just this week, a nano blog that used to be trustworthy and even-handed has gone down the same path. In response to Robert Freitas' recent publication of Nanomedicine Volume IIA: Biocompatibility, Cientifica posted an article containing such phrases as, "swarm of nanobots - more idle speculation," and "books of this ilk," and most dishonorably, "a hobby pursuit."

A book with six thousand references is not a hobby pursuit. I wonder why they are trying so hard to persuade people that it's not worth reading. What is their motivation?

I've been saying "they," but in fact, Paul Holister recently left Cientifica. It appears that Tim Harper is now free to vigorously -- and irresponsibly -- oppose the more advanced kinds of nanotechnology. I'm not usually so openly critical. But false claims that "Martian nanobots ... are equally feasible" should not go unchallenged. This is shabby journalism, and it damages the serious and ongoing discussion of the potential effects of advanced nanotechnology.

Chris Phoenix

e-Parliament

I just learned about a very interesting new web-based experiment in governance.

The e-Parliament is the first world institution whose members are elected by the people. It links democratic members of parliament and congress into a global online forum. Through the e-Parliament, legislators can learn from each other, monitor international agencies and work together to solve common problems. Everyone—parliamentarians, citizens, organizations, journalists—can participate in different ways.

It's too early to tell whether this particular project will succeed or fade away, but even if it fails, it may be a harbinger of some similar effort that will remake the way we govern ourselves.

As we have written before, finding creative and effective answers to the challenges brought by molecular manufacturing will demand an unprecedented collaboration of leaders in science, technology, business, government, and NGOs. It will require participation from people of many nations, cultures, languages, and belief systems.

Because nanotechnology’s awesome potential raises issues unlike any we have encountered before, it is urgent that we begin to develop common understanding, create lines of communication, and build a stable structure that will enable humankind to pass safely through the transition into the nano era. Something like e-Parliament might be an important part of the solution.

Mike Treder

Emerging Mainstream

It seems that stories about emerging -- if not revolutionary -- technologies are becoming more mainstream every day. And you don't have to be a genius to see that these remarkable developments move us steadily closer to the time when all the tools will be there to enable general-purpose molecular manufacturing.

BusinessWeek Online reports on a molecular robot that can walk and pick up and deliver loads of cargo.

Called a motor protein, it has two little feet on one end and a tail that can grab things on the other. Once a special chemical is added to the solution in which it resides, the protein begins moving along strands of fiber that are one-fifth the width of a human hair, says Bruce Bunker, a Sandia researcher who's in charge of the project.

And that's not all...

Nadrian Seeman, professor of chemistry at New York University, dreams of nanorobots so tiny they could be squashed by the foot of a bug. He recently made a molecular device that can execute a half-turn revolution when placed in solution with certain DNA strands. Within a decade, Seeman imagines, this nano-robotic arm could become part of a molecular assembly line -- in a chemical factory so small it might sit on your tabletop.

"[T]he field is moving very fast," says NYU's Seeman. Only a year ago, he says, he showed his students a top-10 list of major challenges nanotechnology faced. Today, three are already resolved. At this pace, he adds, self-assembly and molecular manufacturing will come into commercial use sooner rather than later.

New Scientist has more details on what they say is being hailed as a "major breakthrough" by nanotechnologists.

In a similar vein, our friend Rocky Rawstern, editor of Nanotechnology Now, reports:

A rewritable memory and nanotweezers, both made from DNA, show how such 'gene machines' can be given better memories and more self-control.

Jong-Shik Shin and Niles Pierce from the California Institute of Technology in Pasadena have made a rewritable DNA memory. And Wendy Dittmer and Friedrich Simmel of the University of Munich in Germany have used the biological apparatus for reading out genetic information to control the operation of a pair of 'DNA tweezers'.

This isn't likely to be a very good way of storing and reading data for information technology -- it is slow, and addressing every element via its base sequence rather than simply via its grid reference is cumbersome if there are many elements -- but that's not really the goal. Shin and Pierce say that a DNA array with these reversibly addressable sites could be useful as a template for assembling other molecules or nanoscale building blocks into arbitrary patterns. What's more, a judicious sequence of 'write' operations on the array could be used to transport attached cargo step by step along a particular path. So the DNA memory could serve as a track or scaffold for nanoscale assembly.

[Note: Links to Nature may require registration.]

Interdisciplinary Triumph

Here is Chris Phoenix's review of Nanomedicine:

Robert Freitas is the world's expert in nanomedicine, the use of advanced nanotechnology to build and run medical devices. He's writing a massive reference work on the topic.

Nanomedicine Volume I: Basic Capabilities discusses power, sensing, heat dissipation, control, navigation, and anatomy (with lots of numbers useful to engineers). And a lot of physics: Freitas bases his designs on the fundamental equations, and he shows his work. In fact, when I need to review the use of a physics formula, the first book I grab is Nanomedicine I. Then I try Nanosystems. My physics textbook usually stays on the shelf.

Nanomedicine IIA: Biocompatibility is an equally detailed book, with over 6,000 references. It goes into encyclopedic detail on immunology, cellular adhesion, and a wide variety of other topics. How can nanorobots hide from the immune system? Section 15.2.3.4. Will nanorobots make you throw up? Section 15.2.6.3. Are pure buckyballs biocompatible? Section 15.3.2.1. Will proteins stick to sapphire? Section 15.3.5.1. How elastic is the surface of an erythrocyte? Section 15.5.5.1.2.

(Why do all of these start with 15? Because in the original plan for a three-volume work on nanomedicine, chapter 15 was the biocompatibility chapter. But as Freitas did his research, the chapter grew...and grew...)

Both Nanomedicine I and Nanomedicine IIA are available, in full text, for free, on the Web.

How Nano Works

The folks over at the really cool "How Stuff Works" website have a link from their homepage to CRN's main website. The entry says...

Nanotechnology assemblers may be here within 20 years and will change the world

...and it links to our Current Results Overview page.

Thanks, guys!

Nanomedicine, Vol. IIA

You may have heard about this already, but just in case...

The second volume in the Nanomedicine book series by Robert A. Freitas Jr., Nanomedicine, Vol. IIA: Biocompatibility, is now freely available online in its entirety. First published in hardcover by Landes Bioscience in 2003, this comprehensive technical book describes the many possible mechanical, physiological, immunological, cytological, and biochemical responses of the human body to the in vivo introduction of medical nanodevices, especially medical nanorobots.

You know the phrase "exhaustively researched"? This is the book that term was meant to describe.