Tuesday, July 28, 2015
Nanotechnology has the potential to transform numerous industries, including the field of the medicine. The future may bear witness to drug delivery systems that target a particular site in the body, thanks to basic research being done today. Some of the foundations for these future applications are being developed at the Technical University of Munich (TUM), which demonstrate breakthroughs in the science of using DNA as a programmable building material for nanoscale structures and machines. Among the latest DNA nanodevices created are self-assembling nano robots with movable arms, and scissors that repeatedly open and close every three minutes for four days without breaking.
In reference to the traditional Japanese art of paper folding, the research field of TUM's Prof. Dr. Hendrik Dietz is called "DNA origami." By snapping together complementary shapes instead of zipping strings of base pairs, he has introduced a new method to the modular 3D nanostructure building toolkit. "Once you have built a unit with base pairs," Prof. Dr. Dietz explained, "it's hard to break it apart. So [until now] dynamic structures made using that approach tended to be structurally simple in order to limit the number of base pairs." To build more complex structures and structures with movable parts, his group adapted a weak, short-range binding mechanism called nucleobase stacking.
In nature, weak bonds can be formed when the RNA-based enzyme RNase P "recognizes" so-called transfer RNA. The molecules are guided into close enough range by their complementary shapes. This principle can be used to snap units in place. Three different methods are available to control the shape and action of devices made in this way. "What this has given us is a tiered hierarchy of interaction strengths," Prof. Dr. Dietz said, "and the ability to position - precisely where we need them - stable domains that can recognize and interact with binding partners."
Meanwhile, the team has produced a series of DNA devices - ranging from micrometer-scale filaments that might prefigure technological "flagella" to nanoscale machines with moving parts - to demonstrate their potential fields of application and to begin testing their limits.
Prof. Dr. Dietz ranks among the world's leading researchers in DNA nanotechnology. Earlier this year, he received Germany's most prestigious research award - the Gottfried Wilhelm Leibniz Prize - for his work on this project.
Source: © Technical University of Munich (TUM)
Image: Artist's impression of shape-complementary DNA components that self-assemble into nanoscale machinery. © C. Hohmann / NIM