NYU Chemists Discover New Principle in DNA Self-Assembly

A recent study conducted by chemists at New York University (NYU) demonstrated that DNA tiles are capable of assembling into three-dimensional structures without relying on the hydrogen bonding typically associated with "sticky ends". This research, published in Nature Communications, re-evaluates a fundamental principle within the field of DNA self-assembly.

Simon Vecchioni, a research scientist in NYU's Department of Chemistry and study author, stated that altering the shape of the interface between DNA strands resulted in varied assembly outcomes, indicating that complex matter can be achieved through simple design.

Altering the shape of the interface between DNA strands resulted in varied assembly outcomes, indicating that complex matter can be achieved through simple design.

Background on DNA Nanotechnology

The field of DNA nanotechnology was established by the late NYU Chemistry Professor Ned Seeman. His work involved using synthetic DNA strands as building blocks to construct complex architectures. Seeman's initial discoveries showed that DNA could self-assemble into triangular 3D shapes and co-assemble into crystals if "sticky ends" were incorporated, allowing attachment via hydrogen bonds.

A Novel Shape-Based Assembly Method

Building on this foundational knowledge, researchers at the NYU DNA Lab, including Seeman's colleagues, found that DNA could be guided to assemble solely by its shape, without the need for hydrogen-bonded "sticky ends". Vecchioni compared the process to a jigsaw puzzle, where pieces fit by shape rather than requiring adhesive.

The study demonstrated that the geometric properties of two-dimensional DNA subunits and the flat interface of each double helix could be leveraged to create a diverse collection of complex 3D DNA structures. These structures included new forms with novel twists, inversions, and rotations.

Controlling Mirror DNA

Ruojie Sha, a senior research scientist at NYU's Department of Chemistry and study author, noted that the complexity of the created material was significantly increased. The research also revealed the ability to control assembly outcomes between "right-handed" DNA and "left-handed" mirror DNA.

By adjusting the flat stacking interface, researchers could direct left- and right-handed DNA to avoid, mix, or form layered structures, facilitating interaction and coexistence within the same 3D assemblies. Vecchioni indicated that these findings enable the construction of mirrored materials and provide a method for exchanging information between mirror molecules and standard molecules.

Future Implications

This research demonstrates the potential for creating increasingly complex matter using DNA, establishing a foundation for future DNA-based materials. These materials could have applications in optical, electronic, and biomedical technologies, such as biosensors or drug delivery systems, due to DNA crystals' porous, water-rich structure.