MIT researchers control biological materials with radio waves

Researchers at MIT have taken a step toward the creation of single-atom machines with a report that says that they can ‘speak’ to DNA biomolecules with radio waves.

Researchers at the Massachusetts Institute of Technology (MIT) report in the journal Nature that they can ‘speak’ to DNA biomolecules with radio waves.

MIT researchers predict that radio frequency (RF) biology will have a broad range of applications. Radio-controlled biology may lead to single-atom or single-molecule machines or the ability to hook tiny antennae into living systems to turn genes on and off. Biological machines may one day be used to perform computation, assemble computer components or become part of computer hardware or circuitry.

Because virtually all biological molecules can be linked with gold or other semi-conducting nanoparticles, these molecules can be controlled electronically, remotely, reversibly and precisely, said Shuguang Zhang, associate director of MIT’s Centre for Biomedical Engineering and one of the study’s authors. Such systems will have profound implications for finely dissecting detailed molecular interactions and formations, he said.

‘Manipulation of DNA is interesting because it has been shown recently that is has potential as an actuator and can be used to perform computational operations,’ said Joseph M. Jacobson, associate professor at the MIT Media Lab and an author of the study. Jacobson, head of the Media Lab’s Molecular Machine group said the ultimate goal is a machine on the single-atom or single-molecule level.

It’s hard to manufacture computer chips much smaller than 30 nanometers, but biology is said to have an excellent track record at creating tiny workable systems. The cell itself is a phenomenal little machine with its own power supply and memory. ‘If we’re interested in molecular-scale machines, biology is a wonderful place to start,’ Jacobson said.

Jacobson worked with researchers from MIT’s Centre for Biomedical Engineering to attach tiny radio-frequency antennae – a metal nanocluster of less than 100 atoms – to DNA.

When a radio-frequency magnetic field is transmitted into the little antennae, the molecule is hit with energy and responds.

Hybridisation is the process of joining two complementary strands of DNA or one each of DNA and RNA to form a double-stranded molecule. In dehybridisation, the strands unwind. Using this technique, the researchers dehybridised double-stranded DNA in seconds. The switching is reversible, and did not effect neighbouring molecules.

Nanocrystals can be attached to proteins as well as to nucleic acids. This opens the possibility of switching more complex processes such as enzymatic activity, biomolecular assembly, gene expression and protein folding. The function of cells’ components and the cell life cycle itself may be electronically regulated with radio frequency, Jacobson said.

The goal is build molecules into systems that turn on and off depending on the electronic commands they receive. It may one day be possible to hook the antennae into living systems and turn genes on and off.

The fine electronic controls of biological regulation will likely become more and more important in understanding complex molecular interactions in great detail, said co-author Kimberly Hamad-Schifferli, a postdoctoral associate in the MIT Media Lab, because there is currently no other way to achieve fine local control without disturbing neighbouring molecules. He likened the level of communication to using a mobile phone to convey a message to a single person in a crowd.

‘Radio frequency biology provides us with some extraordinary tools and with unprecedented precision controls to study biomolecules and their interactions. These new tools and technologies will undoubtedly accelerate and advance our knowledge in finest detail. It not only opens new avenues for us to ask big and deep questions but also to attain the ultimate answers in biology,’ concluded Zhang.