Ahead of the curve: New techniques advance DNA nanotech

December 27, 2022

DNA nanotechnology is a rapidly evolving field, thriving in the borderlands between biology and chemistry. Pioneering design principles allow researchers to construct an extraordinary array of two- and three-dimensional forms at the scale of just billionths of a meter, using the molecule of life as a building material.

In a new study, Professor Hao Yan from Arizona State University, Professor John Reif from Duke University and their colleagues describe a technique for considerably expanding the versatility and range of DNA nano-objects. An automated computer tool allows researchers to custom design structures, which self-assemble from DNA. A few of the nanoarchitectures — measuring just a few billionths of a meter is size — are seen in this graphic, along with accompanying magnified images of the completed structures. Illustration courtesy of Duke University Download Full Image

The method allows researchers to produce tiny structures displaying curvatures and asymmetries that are difficult or impossible to create using conventional approaches. The study describes a first-of-its-kind computer-aided design tool that can automate the complex and cumbersome design process, ensuring that the nanoarchitectures properly assemble into the desired forms.

“The collaboration between computer scientists and chemists made designing DNA nanostructures with complex curvatures much easier, assisted by the newly developed automated design software,” Yan said.

In addition to directing the Biodesign Center for Molecular Design and Biomimetics at Arizona State University, Yan is the Milton D. Glick Distinguished Professor in Chemistry and Biochemistry with ASU’s School of Molecular Sciences. He has just been elected to the rank of NAI Fellow by the National Academy of Inventors.

The study appears in the current issue of the journal Science Advances.

The new technique is a variant of a process known as DNA origami, in which pieces of DNA are assembled like nanoscale tinker toys, using the base-pairing properties of DNA’s four nucleotides. These nucleotides stick together in a regular and predictable manner, enabling nanoarchitects like Yan, Reif and colleagues to design elaborate structures that self-assemble in a test tube. The delicate nanoarchitectures are so small, some 50,000 of them could comfortably rest on the head of a pin.

DNA origami has been used to create forms of aesthetic beauty as well as those of importance for biomedical, computer and electronic device applications. A few of these innovative designs include a DNA spider-like walker, stars, quasicrystals, flowers, birds and other diverse shapes, cartwheeling nanomachines and cancer-fighting nanobots programmed to seek and destroy tumors. These and many other infinitesimal architectures can be visualized using sophisticated techniques like transmission electron microscopy.

Despite the impressive and growing assortment of nanoforms built with DNA, researchers still struggle to design and build asymmetric DNA forms and those of irregular shape, involving changes in curvature.

In conventional DNA origami, a single strand of DNA is twisted into a scaffold of the desired nanoform through base-pairing properties, then fixed in place with shorter staple strands. Although the technique has proven highly versatile, some nanoforms are exceptionally difficult to design and fabricate, involving time-consuming and tedious trial and error, as many variables can adversely affect proper self-assembly.

Among these are fully enclosed, capsule-like DNA structures, useful for many applications, including sequestering molecules to be moved from place to place and shielding therapeutic drugs from degradation in the body, before they can reach their intended targets.

Composing such forms using traditional DNA origami methods is taxing and unreliable, often resulting in inaccurate or failed structures. The new technique introduces curved DNA helices into the design process, offering much more fine-grained control over resulting geometries. 

Using bundles of DNA helices in the design process, the researchers were able to exert fine-grained control over both concave and convex curvatures, compared with conventional block-based designs. A probabilistic algorithm sorts through myriad design possibilities for a given form, optimizing strand routing for each design, without the need for painstaking and inaccurate human trial and error. The computer-guided, curved DNA helices enable researchers to more accurately approximate nature’s astonishing variety and geometric ingenuity. 

The new open-source software program was developed by PhD student Dan Fu in Reif’s group at Duke University. The curved DNA nanostructures were assembled and imaged by students Raghu Pradeep Narayanan and Abhay Prasad in Yan’s lab at ASU.

The software relies on new techniques of DNA design first described in 2011 by Yan, who was a postdoc with Reif at Duke 20 years ago before joining the faculty at ASU. The method involves coiling a long DNA double helix into concentric rings that stack on each other to form the contours of the desired object, like using coils of clay to make a pot.

The study describes the construction of bowls, spheres and vases, as well as an ellipse and a clover pattern, which combined concave and convex curvatures. Multilayer designs combined with targeted reinforcement of these structures prevent structural disintegration or collapse, even under conditions of high strain and curvature.

The design advances will enable researchers to broadly expand an already diverse menagerie of DNA forms.

This research was supported by the National Science Foundation (1909848, 2113941, 2004250, 1931487).

Richard Harth

Science writer, Biodesign Institute at ASU


ASU School of Music, Dance and Theatre to host international piano competition

43 competitors to perform in biennial contest Jan. 3–8 in Tempe

December 27, 2022

Arizona State University's School of Music, Dance and Theatre will host the 10th Bösendorfer and Yamaha USASU International Piano Competition on Jan. 3–8.

Recognized as among the leading international piano competitions, this year’s competition attracted 295 pianists from 24 different countries, according Baruch Meir, artistic director of the competition and associate professor of piano in the School of Music, Dance and Theatre. Of those, 43 applicants were selected to perform in the semifinal and final rounds.   Download Full Image

Prizes include more than $50,000 in cash awards, performance opportunities and recording contracts for the top winners. All performances will be in the Katzin Concert Hall on the Tempe campus.

New to the competition this year is access to information about the event through the ASU Special Events app. Both the app and website provide details about the competitions, competitors, schedule of performances, jury, tickets, parking, prizes and more.

Meir created the first competition in January 2006, and it was held annually through 2009. In 2011 it became a biennial competition. After that, the only year the competition was postponed was 2021, due to COVID-19.

Meir, who grew up in Israel, said his inspiration for the competition began when he was a young boy and would watch the pianists in the Arthur Rubenstein International Competition, one of the world’s top contests. Throughout the years, the organizer and founder of the Rubinstein competition, Yasha Bistritzky, noticed Meir's dedication and invited him to become the competitors’ coordinator in 1992.

“It was an incredible experience as people came from all over the world to participate and watch,” Meir said. “Experiencing the excitement, listening to the talented pianists and creating personal contacts was amazing.”

In 1994, Meir came to ASU to earn a Doctor of Musical Arts degree and was invited back to work with the Rubenstein competition in 1995.

“It was then that I decided that one day I would start a competition,” Meir said.

In 2003, Meir was named a Bösendorfer Concert Artist and met the directors and CEO of the Bösendorfer piano company during his recognition recital in Vienna, Austria. The CEO liked his playing, so Meir said he took the opportunity and proposed that a Bösendorfer competition should be created.

“It was something I was passionate about, and I persuaded the CEO of Bösendorfer with my passion,” Meir said.

Bösendorfer partnered with Schimmel on the competition through 2011. In 2013, Bösendorfer was bought by the Yamaha Corporation, and the competition was renamed the Bösendorfer and Yamaha USASU International Piano Competition.

Meir said the main benefit for students who compete is recognition and exposure.

“We, as artists, need a stage and recognition,” Meir said. “Winning a top competition helps you develop yourself as an artist and your professional career if you have a title of laureate on your resume.”

According to Meir, this year’s Bösendorfer-Yamaha competition has the second largest pool of competitors in the history of the competition. This year, the competition is also offering a new award for a best performance of a piece composed by a BIPOCBlack, Indigenous or people of color. or female composer.

Daily and weekly passes are available in advance for purchase online or by calling ASU Purplepass at 480-965-6447. The winners’ recital on Jan. 8 requires a separate ticket from the daily or weekly pass.

Lynne MacDonald

communications specialist, School of Music