Scientists have crafted DNA structures without the need for hydrogen bonds, challenging a long-held paradigm in DNA self-assembly. This groundbreaking study, led by NYU chemists, reveals that DNA tiles can assemble into 3D structures without the traditional 'sticky ends' and hydrogen bonding. Published in Nature Communications, the research demonstrates that altering the interface between DNA strands can lead to diverse assembly outcomes, showcasing the power of simple design in creating complex matter.
The late NYU Chemistry Professor Ned Seeman, a pioneer in DNA nanotechnology, initially discovered that DNA could self-assemble into triangular 3D shapes with the addition of sticky ends and hydrogen bonds. However, in this new study, Seeman's colleagues in the NYU DNA Lab explored an alternative approach. By focusing on the shape of the interface, they found that DNA could assemble like a puzzle, without the need for sticky ends or hydrogen bonding.
"With a jigsaw puzzle, you don't need glue; the shapes just need to fit together," explains study author Simon Vecchioni. "And it turns out that the triangular shape central to this work is highly efficient at self-assembling without sticky ends."
The researchers generated an extensive library of intricate, varied 3D structures made entirely from DNA, leveraging the geometry of two-dimensional subunits and the flat interface at the end of each double helix. Many of these structures were novel forms and shapes, marked by unique twists, inversions, and rotations.
"We've significantly increased the complexity of the material we're creating," says study author Ruojie Sha. "By introducing tiles with specific geometries and interfaces, we allow nature to determine the best outcome. In this way, we're learning from a natural form of computing."
One of the study's most intriguing findings was the ability to control assembly outcomes between traditional 'right-handed' DNA and 'left-handed' mirror DNA. By making changes at the flat stacking interface, the researchers could make left- and right-handed DNA avoid each other, mix, or form layered structures, essentially prompting mirror DNA to communicate and coexist within the same 3D structures.
"We've essentially built mirrored materials, but more importantly, we've found a way to exchange information between the mirror world and our world," Vecchioni notes. "This opens up possibilities for using everyday molecules to gain information from mirror ones, potentially impacting the debate on mirror life."
The study's implications are far-reaching, demonstrating the potential for creating increasingly complex matter using DNA. This lays the foundation for future DNA-based materials that could revolutionize optical, electronic, and biomedical technologies. For instance, DNA crystals' water-based nature and highly networked structures could be valuable for creating biosensors or drugs.
The research team, which includes Karol Woloszyn, Andrew Horvath, Mara Jaffe, Lara Perren, Joe Rueb, Samyra Mahiba, Yoel P. Ohayon, and James W. Canary from NYU's Department of Chemistry, as well as Nataša Jonoska from the University of South Florida, was supported by various grants from the National Science Foundation, the Department of Energy, and NASA. This study not only showcases the innovative potential of DNA self-assembly but also invites further exploration and discussion on the possibilities of mirror DNA and its applications.
