It’s Called DNA
Professor, Molecular Biosciences
“It’s a robot on the nanoscale that moves. And its materials — rather than nuts and bolts — are DNA.”
Andy Ellington is a professor of molecular biosciences in the College of Natural Sciences. Ellington and his team at The Ellington Lab are more like engineers than biologists, he says. As biotechonologists they look at DNA as a key building material in the frontier of computational design.
Recently Ellington and two members of his lab, Cheulhee Jung and Peter B. Allen, published a study in the journal Nature Nanotechnology about their design of DNA nanorobots that were able to “walk,” unprogrammed and in different directions, over a DNA-coated surface. One day, this kind of DNA walker might be a cancer detector roaming the human body searching for cancerous cells; or perhaps an ingredient in a future metamaterial responding to the needs of the body.
We talked to Ellington about the field of nanotechnology, the future of the DNA walker and his approach to research.
What is nanotechnology?
Nanotechnology is all manner of things that work at the nanoscale. There is nanotechnology for materials, nanotechnology for medicine. You could suggest that some forms of synthetic life fall within nanotechnology.
What is your motivation for studying nanotechnology? What drives your research?
My lab studies a large number of things, including nanotechnology. The ability to manipulate individual molecules may make it possible to create entirely new materials or machines. Engineering at the nanoscale will enable us to create new technologies in the same way that the miniaturization of electronic circuitry enabled modern electronic devices, making them smaller, faster and cheaper.
The DNA Walker has been referred to as a nanomachine or nanorobot. How can DNA be a machine?
When most people think of a machine, they think of things moving. The DNA walker is a robot on the nanoscale that moves, and its materials — rather than nuts and bolts — are DNA. So, yes, it is absolutely a nanomachine.
What could be a possible use for a nanomachine like the DNA Walker? Why is your development so significant?
When I was a child there was a great movie called the Fantastic Voyage, where they shrunk things down to the cellular scale. While we are not shrinking things down using a shrink ray, if you make objects like nanorobots that can crawl through your system and find cancerous cells and take them out, one can see how that would be useful. The very principles we put into our nanorobot are the very principles that would presumably go into a therapeutic nanorobot.
Would the DNA walker potentially hunt cancer alone or would it be part of a larger mechanism?
If you can build one robot, you can build a hundred. They can gang together to do tasks, and all of a sudden a nanorobot made from molecules doesn’t seem so silly. They are undertaking coordinated behavior like a swarm of bees. They would traverse the body and find the cancer cell, and they would potentially kill it. That is no longer completely science fiction — you can now imagine DNA nanomachines potentially doing that.
And the DNA walker is a step in that direction?
Tiny tiny little step. But, yes, it is definitely one of those steps. When people first invented transistors they looked pretty kludgy. They were basically wires stuck in a germanium crystal. Then they reduced them to vacuum tubes. Then they reduced them to integrated circuits. And then they put a million billion of them on a chip, and Michael Dell got rich.
What are the implications for the DNA Walker beyond health?
Imagine a different type of computer: The kind where the memory elements are molecules and the transactions between the memory elements are things like DNA walkers. Instead of having electrons being the medium of computation, now it’s carbon.
What kind of computation can we do with carbon? How is the computation different? Maybe we can make smart materials where within the material things crawl around to help it morph to new forms, or decide to be brittle or not brittle.
I think there is future in DNA computation with distributed computational elements with things not unlike DNA walkers. Perhaps I seem crazy, but so would the person who stuck wires in germanium if he had also said, “Someday we are going to have cell phones.”
How big is the leap from today’s DNA Walker — which is moving on the substrate it was designed to walk on — to being able to put a swarm of these in the body to hunt down cancer cells or work together as a new type of computer? That seems like a big leap.
That is a big leap. And I can’t do this by myself. What needs to happen is somebody needs to come up with the programming language. You can make a computer, but if it sits there without a language it can’t do a whole lot. I make the basic circuitry, but I need the language to program it.
To get to that language I need theorists to work with. One of the great things about UT is we just hired one of the best theorists in this area. David Soloveichik, a computer engineer, and I are going to try and make this leap. I’m the hardware guy and he is the software guy. Between us we hope we can make these advances, because I know I can’t do this on my own.
“There is only one thing on Earth that I know of that can store information in an incredibly complex way without electronics, and it’s called DNA.”
What role do innovation and creativity play in your research?
For a biotechnologist, these are all we got. That’s the only way my discipline moves forward. Biology is always what I think of as a dissecting discipline, but I would rather build a sundial than take apart a watch. If I want to make new life, new life is on me.
Every creative process has inspiration. Where do you draw inspiration?
I feel like sci-fi and fantasy are critical parallels to science. Writers come up with things that are absolutely impossible from a pure science point of view, but they also point you in the direction you should go. If you can’t imagine it, you can’t begin to build it.
What do you want people to understand about your research with DNA?
There is a fundamental thing that I hope everyone can grasp: There is only one thing on Earth that I know of that can store information in an incredibly complex way without electronics, and it’s called DNA. Other than the circuit board on your computer, DNA is it. It’s the only way to store that much information. It’s the only game in town. I am working with the only material — anywhere, anytime — that can be what I like to call a “matter computer.” We need to learn not only the secrets of life, but how to program matter computers.