By emulating nature’s design principles, a team at Harvard’s Wyss Institute for Biologically Inspired Engineering, HMS and Dana-Farber Cancer Institute has created self-assembling nanodevices made of DNA that can be programmed to change shape and position on demand. The devices are suitable for medical applications, in contrast to existing nanotechnologies, because DNA is both biocompatible and biodegradable.
“This new self-assembly–based nanofabrication technology could lead to nanoscale medical devices and drug delivery systems, such as virus mimics that introduce drugs directly into diseased cells,” said co-investigator and Wyss Institute director Don Ingber. A nanodevice that can spring open in response to a chemical or mechanical signal could ensure that drugs not only arrive at the intended target but are also released when and where desired.
Built at the scale of one billionth of a meter, each nanodevice is made of a circular, single-stranded DNA molecule that, after being blended with many short pieces of complementary DNA, self-assembles into a predetermined 3D structure. The structure’s strength and stability result from the way it distributes and balances the counteracting forces of tension and compression.
“These little Swiss Army knives can help us make all kinds of things that could be useful for advanced drug delivery and regenerative medicine,” said lead investigator William Shih, Wyss core faculty member and an HMS associate professor of biological chemistry and molecular pharmacology at DFCI. First author Tim Liedl is now a professor at Ludwig Maximilians University in Munich.
The architectural principle that the devices are based on—called tensegrity—has been the focus of artists and architects for many years, but it also exists throughout nature. In the human body, for example, bones serve as compression struts, with muscles, tendons and ligaments acting as tension bearers that enable people to stand up against gravity. The same principle governs the way cells control their shape at the microscale.
The work appeared online June 20 in the journal Nature Nanotechnology.
For more information, students may contact William Shih at william_shih@dfci.harvard.edu.
Conflict Disclosure: The authors declare no conflicts of interest.
Funding Sources: The Wyss Institute for Biologically Inspired Engineering at Harvard University, National Institutes of Health, Deutscher Akademischer Austauschdienst Fellowship, Swedish Science Council Fellowship and Claudia Adams Barr Program Investigator award; the content of this work is solely the responsibility of the authors.
