Bendable molecules: A bundle of DNA helices (top row) can be made to bend at precise angles (the other rows) by introducing or deleting base pairs in the DNA sequence.
William Shih, a co-author of the study and assistant professor of biological chemistry and molecular pharmacology Harvard Medical School, says that the ability to make curved structures adds an important element to the DNA nanoscience toolbox. He points out that objects like rings, springs, and gears are important for machines at the macroscale, while cells also contain elements with curved parts, suggesting that these properties are important on the nanoscale. “If we didn’t have this general building capability, we would be handicapped in our ability to build useful devices,” he says.
Chengde Mao, an associate professor in analytical chemistry at Purdue University, calls the achievement “surprising” and says that his own lab has attempted to make similar structures and failed. He says not only that the work shows that DNA can be twisted and bent to extreme degrees but that “one of the nice things is that it’s a really smooth curve,” whereas other attempts have resulted in shapes that are pixilated.
The practical applications of the technique are still unclear, but there are many possibilities. Since the DNA shapes described in the Science paper are the size of an average virus, Shih says they could perhaps be designed to enter a cell like a virus in order to release a drug. DNA parts might also be used to design molecular electronics, which could someday offer a new level of miniaturization for faster computers.
Yan says that the study adds to the impressive abilities of DNA, but adds that scientists need to study these structures further to see how stable they are and how well they hold up over time.