DNA-Based Robots.

Author:Gorder, Pam Frost

Researchers have devised a magnetic control system to make tiny DNA-based robots move on demand--and much faster than recently possible. In the journal Nature Communications, Carlos Castro and Ratnasingham Sooryakumar and their colleagues from Ohio State University report that the control system reduced the response time of prototype nano-robot components from several minutes to less than a second.

Not only does the discovery represent a significant improvement in speed, this work and another recent study herald the first direct, realtime control of DNA-based molecular machines.

The discovery one day could enable nano-robots to manufacture objects--such as drug-delivery devices--as quickly and reliably as their full-size counterparts. Previously researchers only could move DNA indirectly by inducing chemical reactions to coax it to move certain ways, or introducing molecules that reconfigure the DNA by binding with it. Those processes take time.

"Imagine telling a robot in a factory to do something and having to wait five minutes for it to perform a single step of a task. That was the case with earlier methods for controlling DNA nano-machines," explains Castro, associate professor of mechanical and aerospace engineering.

"Real-time manipulation methods like our magnetic approach enable the possibility for scientists to interact with DNA nano-devices and, in turn, interact with molecules and molecular systems that could be coupled to those nano-devices in real-time with direct visual feedback."

In earlier work, Castro's team used a technique called DNA origami to fold individual strands of DNA to form simple microscopic tools like rotors and hinges. They even built a "Trojan horse" out of DNA for delivering drugs to cancer cells.

For this, the researchers joined with Sooryakumar, professor of physics. He previously developed microscopic magnetic "tweezers" for moving biological cells in biomedical applications, such as gene therapy The tweezers actually were made of groups of magnetic particles that moved in sync to nudge the cells where people wanted them to go...

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