DNA origami: revolutionizing cell nucleus delivery of functionalized DNA nanostructures

Imagine delivering precision nanodevices directly into the nucleus of human cells—scientists are doing just that with DNA origami nanostructures!   

When long single strands of DNA encounter many short single strands, they can spontaneously fold into shapes predetermined by their nucleic acid composition. Rothemund et al. (2006) took this DNA construction to a new level of complexity, creating 2D smiley faces that charmed the world. DNA origami (DO) is seen as a promising tool for applications like drug delivery and biosensing. Now, Roozbahani et al. (2024) have developed a way to smuggle these DNA nanostructures into human cell nuclei—where most of the important genetic action happens—which could pave the way for targeted gene therapies and advanced cellular imaging.   

Why is this important?

Until now, getting DNA nanostructures into the cell nuclei without damaging them has been a major hurdle. In this study, researchers developed a method to conjugate DO nanostructures to antibodies that bind to nucleic proteins when they are newly synthesized in the cytoplasm. The proteins naturally cycle to the nucleus, ‘piggybacking’ the DO with them. This opens doors to target molecular structures and devices to the nucleus, for the delivery of nanoscale tools to probe or control the genetic or epigenetic processes that regulate cell function.

DNA origami stability and design

Researchers designed two types of DNA nanorods using advanced folding techniques, a 30-nm long 8-helix bundle (8HB), and a 90-nm long 26-helix bundle (26HB). They studied the stability of the DO in cell culture media, cell lysates, and live cells. The structures remained stable both in cell media and within live cells for at least 24 hours.

Nuclear delivery mechanism

To enable intranuclear functions that depend on DNA structure, not just its sequence, the researchers devised an effective way to deliver functional DNA nanostructures into live cell nuclei. They conjugated the DNA nanorods with an antibody that targets RNA polymerase II, a key enzyme in gene transcription, successfully piggybacking these structures into live human cell nuclei. The DNA structures remained stable, even in the highly active environment of the cell nucleus, and demonstrated sub-diffusive motion, making them ideal candidates for future biophysical probing.    

Concept for importing DNA origami nanostructures into the nucleus. DNA origami nanostructures functionalized with RNA polymerase Pol II targeting antibodies and 8 Cy5 fluorophores are electroporated into cells, bind to Pol II, and then are imported into the nucleus. Figure reused from “Piggybacking functionalized DNA nanostructures into live-cell nuclei.” (Roozbahani et al. 2024, Sci Adv.) under a CC BY 4.0 license

Application potential

This breakthrough in delivering DNA nanostructures into live cell nuclei could revolutionize fields like gene therapy and cellular imaging. By controlling molecular interactions within the nucleus, scientists could potentially manipulate gene expression or monitor chromatin structures with unprecedented precision.

Conclusions

DO, once regarded as a curiosity used to design tiny smiley faces, has now found its killer application—piggybacked directly into the nucleus to interact with a cell’s genetic machinery! This innovative approach is an exciting leap toward new biophysical tools and therapeutic techniques. By leveraging antibodies and proteins that naturally move into the nucleus, researchers can now deliver functionalized DNA nanostructures into the most crucial part of the cell without compromising their structural integrity.

With this breakthrough, the promise of precision medicine—where treatments can be tailored down to the cellular level—just got a little closer.

References

Rothemund, P. Folding DNA to create nanoscale shapes and patterns. Nature 440, 297–302 (2006).

Roozbahani GM, et al., Piggybacking functionalized DNA nanostructures into live-cell nuclei. Sci Adv. 10 (27) (2024).

Takara Bio products used in this exciting research

Guide-it Long ssDNA Production System v2 kit
PrimeSTAR® Max DNA Polymerase