RNA tiles form nanopatterns

Scientists have been bending DNA to various technological ends, but relatively little attention has been given to DNA's cousin, RNA.

Researchers from the University of California at Santa Barbara and the University of California at San Diego have developed a method of coaxing artificial RNA molecules to self-assemble into specific shapes, much like a jigsaw puzzle automatically assembling.

The structures could eventually be used as templates for nanochips, nanocircuits and nanocrystals; it could also eventually be used in medical applications to help body parts such as bone heal or regenerate, according to the researchers.

RNA is made from strings of four types of bases connected to a sugar-phosphate backbone. Its biological duty is to replicate information represented by segments of DNA and transport the information outside a cell's nucleus.

The researchers' programmable RNA building blocks contain sequences of bases that connect to other strands of RNA to assemble into squares of four strands of RNA each. The squares can then assemble into larger shapes. The RNA tiles can be programmed to attach to polymer molecules or semiconductor particles and then position themselves within an RNA grid.

Previous research has shown this is possible with DNA. RNA has several advantages over DNA, according to the researchers. It is more rigid and holds its shape over a wider range of temperatures. DNA is more stable over time, however.

The method could be used in practical applications in 5 to 15 years, according to the researchers. The work appeared in the December 17, 2004 issue of Science.