Let a Thousand DNA Flowers Bloom

When I saw a headline about “DNA flowers,” I was nonplused. I mean: aren’t all flowers made out of DNA, like every living thing on our planet? Well, it turns out that the DNA flowers are actually soft robots – make that nanobots – so my interest was definitely piqued.

Visualization of DNA flowers Credit: Justin Hill, Philip Rosenberg, and Ronit Freeman

The DNA flowers are out of the Freeman Lab at the University of North Carolina, led by Dr. Ronit Freeman, and the research about them was just published in Nature Nanotechnology with the less sexy title “Reversible metamorphosis of hierarchical DNA-organic crystal.”  Had I seen that before “DNA flowers” I probably would have passed it over, so I’m glad someone has an eye towards marketing.

Designer Daniel Burham famously said: “Make no little plans,” and I kind of think he’d like Dr. Freeman. Her bio says she has formal training in computer science, chemistry, nanotechnology, and regenerative medicine (plus even ballroom dancing, if you’re counting), and she probably needs all that training, because her primary interest is “in supramolecular self-assembly, a field where common biological materials like DNA and proteins are seen not simply as information carriers, but also as tunable structural materials for next-generation sensors, nano robots, drug breakthroughs, and clinical tools.”

Accordingly, what the Lab has done now is to combine DNA with inorganic materials to allow them to respond to their environment. Professor Freeman says: "We take inspiration from nature's designs, like blooming flowers or growing tissue, and translate them into technology that could one day think, move, and adapt on its own,"

Indeed, the Freman Lab prides itself on “bioinspired technologies,” the purpose of which is: “We engineer living and synthetic materials to accelerate healthier outcomes for global communities.” The website talks about “building block designs.” featuring hierarchical self-assembly, temporal structural reconfiguration, and adaptive behavior.

Hence, DNA flowers. 

The flowers are actually shaped like flowers, although they are microscopic, and what makes them both interesting and potentially useful is that the various strands of DNA allow them to move, open or close, or trigger chemical reactions, based on environmental cues like temperature, acidity, or chemical signals. The DNA sequences guide nanoparticles to organize into complex structures, which can reverse shape as desired.  

"People would love to have smart capsules that would automatically activate medication when it detects disease and stops when it is healed. In principle, this could be possible with our shapeshifting materials," said Professor Freeman. “In the future, swallowable or implantable shape-changing flowers could be designed to deliver a targeted dose of drugs, perform a biopsy, or clear a blood clot."

Yeah, I’d love that, and I bet you would too.

The team acknowledges that the technology is in the early stages, but see a future where, say, a DNA flower is injected into a cancer patient, in whom it travels to a tumor, whose acidity causes the petals to release a medication or even take a tiny tissue sample. When the tumor is gone the DNA flower would deactivate until/unless new environmental triggers reactivate it.  

Thinking beyond healthcare, the team sees their creations helping to clean up environmental contamination, or as a great digital storage device -- up to two trillion gigabytes in just a teaspoon. 

The fact that the DNA flowers can sense and respond to their environment makes the team believe these are a major step forward in bridging the gap between living systems and machines. We’re going to see more of that in the rest of the 21^st century.

Credit: Freeman Lab

The Freeman lab has some big ambitions. It wants to discover “new and creative means of detecting viruses, treating illnesses, effectively targeting and delivering payloads, and interfacing with natural biology.” Four key ways it is attacking that goal are:

Sensing: “developing rapid testing technologies that are easy to use, location independent, robust in design, and cost effective for production.”: “In recognizing, respecting and studying natural mechanisms, we are able to mimic them in order to develop effective biotherapies and advance biomedical engineering.”

Biomimicry: “In recognizing, respecting and studying natural mechanisms, we are able to mimic them in order to develop effective biotherapies and advance biomedical engineering.”

Therapeutics: “This can involve administering an external drug, developing a safe and effective means to deliver that drug to the desired site, or developing a means to program natural biology to reverse the effects of a disease.”

Soft matter: “Soft Matter is an umbrella term for sciences concerned with topics ranging from textile materials, to fluid mechanics, granular distribution, biological materials and much more.”  

All very cool, all thinking about a future that is different than the past, so kudos to them. DNA flowers aren’t the first thing the Freeman Lab has done, and I’m pretty sure they won’t be the last. I can’t wait to see what’s next.

And you though Bill Belichick went to UNC for the football…