One Scientist’s Bid to Build Cancer-Killing Nanorobots
May 4, 2014, 6:00 AM PDT
The term “cancer killing nanorobot” could conjure up all sorts of images, the best involving teeny tiny laser eyebeams.
What you wouldn’t expect is the illustration that pops up in Shawn Douglas’ slide deck, which looks more like a colorful rope basket split in half.
The fresh-faced assistant professor at the UC San Francisco School of Medicine is seated in his tidy office in Genentech Hall, the grand centerpiece of the university’s young Mission Bay campus, patiently walking me through the art and science of DNA design.
The software rendering in question actually represents coiled strands of DNA, nearly 200 of them twisted into just the right shape and texture to latch onto certain types of cells. Antigens on the surface that signal the cells are cancerous act as a kind of key that unlocks the structure, flipping it open like a clam shell and unleashing a drug that can bind with the aggressor cells and instruct them to self-destruct.
The promise is a highly targeted method of drug delivery, precision guided missiles that leave healthy cells alone — as opposed to the kill-everything-cluster-bombs of chemotherapy.
UCSF assistant professor Shawn Douglas
And here’s the interesting part: Douglas and his peers have actually produced the nanorobots and they appear to work. At least in cell culture flasks.
How they did it says a lot about where we are and where we’re going in synthetic biology, an emerging field that allows scientists to custom design DNA, proteins and organisms to carry out specific tasks. The tools and techniques have already delivered cheaper versions of drugs like Artemisinin and promise a long list of novel therapeutics, vaccines, biofuels, nano materials and more.
“You can almost run that question in reverse and say ‘what won’t (synthetic biology) affect?’” said George Church, a professor of genetics at Harvard Medical School and co-author of “Regenesis: How Synthetic Biology Will Reinvent Nature and Ourselves.”
‘Nature’s building blocks’
Douglas said that the ability to program “nature’s building blocks” the way we code computers represents the early stage of a revolution that could have more profound effects than information technology.“We already have a proof of concept that exists,” he said, noting that billions of years of evolution have produced “examples of the power of self-assembly an order of magnitude more sophisticated and complicated than anything anyone has ever built with silicon.”
“We’re doing the really low-level, basic building blocks now,” he added. “But once we get tools in place to make it easier to program matter then things will really take off.”
Of course, there are plenty of scarier scenarios as well, where bad actors use the same technology to release deadly new viruses into the world or other sorts of bio-weapons. So science’s improving capabilities also prompt important questions about appropriate boundaries, procedures and regulations.
Stars and smiley faces
Douglas is soft-spoken, exceedingly precise in describing his work and quick to credit collaborators and fellow scientists.
He began drawing in DNA around 2005, as a graduate and then doctoral student at Harvard. He said he was following in the footsteps of pioneers like Nadrian Seeman and Paul Rothemund, who seized media attention after creating self-assembling “DNA origami” like stars and smiley faces.
See Rothemund’s TED Talk here: