Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unlocking PNA's superpowers for self-assembling nanostructures

12.06.2020

Researchers at Carnegie Mellon University have developed a method for self-assembling nanostructures with gamma-modified peptide nucleic acid (γPNA), a synthetic mimic of DNA. The process has the potential to impact nanomanufacturing as well as future biomedical technologies like targeted diagnostics and drug delivery.

Published this week in Nature Communications, the work introduces a science of γPNA nanotechnology that enables self-assembly in organic solvent solutions, the harsh environments used in peptide and polymer synthesis. This holds promise for nanofabrication and nanosensing.


This representation shows gamma-modifications (in white) uniformly decorating the structure, increasing binding strength and providing chemical modification.

Credit: College of Engineering, Carnegie Mellon University

The research team, led by Assistant Professor of Mechanical Engineering Rebecca Taylor, reported that γPNA can form nanofibers in organic solvent solutions that can grow up to 11 microns in length (more than 1000 times longer than their width). These represent the first complex, all-PNA nanostructures to be formed in organic solvents.

Taylor, who heads the heads the Microsystems and MechanoBiology Lab at Carnegie Mellon, wants to leverage PNA's "superpowers." In addition to its higher thermal stability, γPNA retains the ability to bind to other nucleic acids in organic solvent mixtures that would typically destabilize structural DNA nanotechnology. This means that they can form nanostructures in solvent environments that prevent formation of DNA-based nanostructures.

Another property of γPNA is that it is less twisted than the double helix of DNA. The result of this difference is that the "rules" for designing PNA-based nanostructures are different than the rules for designing structural DNA nanotechnology.

"As mechanical engineers, we were prepared for the challenge of solving a structural design problem, Taylor said. "Due to the unusual helical twist, we had to come up with a new approach for weaving these pieces together."

Because the researchers in Taylor's lab seek to use dynamic shape change in their nanostructures, they were intrigued to discover that morphological changes - like stiffening or unraveling - occurred when they incorporated DNA into the γPNA nanostructures.

Other interesting characteristics that the researchers want to explore further include solubility in water and aggregation. In water, these current nanofibers tend to clump together. In organic solvent mixtures, the Taylor lab has demonstrated that they can control whether or not structures aggregate, and Taylor believes that the aggregation is a feature that can be leveraged.

"These nanofibers follow the Watson-Crick binding rules of DNA, but they appear to act more and more like peptides and proteins as PNA structures grow in size and complexity. DNA structures repel each other, but these new materials do not, and potentially we can leverage this for creating responsive surface coatings," said Taylor.

The synthetic γPNA molecule has been perceived as a simple DNA mimic having desirable properties such as high biostability and strong affinity for complementary nucleic acids.

"We believe through this work, we could additionally adjust this perception by highlighting the ability of γPNA to act as both - as a peptide mimic because of its pseudopeptide backbone and as a DNA mimic because of its sequence complementarity. This change in perception could allow us to understand the multiple identities this molecule can leverage in the world of PNA nanostructure design," said Sriram Kumar, a mechanical engineering Ph.D. candidate and the first author on the paper.

Although PNA is already being used in groundbreaking gene therapy applications, there is still a lot to learn about this synthetic material's potential. If complex PNA nanostructures can someday be formed in aqueous solutions, Taylor's team hopes that additional applications will include enzyme-resistant nanomachines including biosensors, diagnostics, and nanorobots.

"PNA-peptide hybrids will create a whole new toolkit for scientists," Taylor said.

The researchers used custom gamma modifications to PNA that were developed by Danith Ly's lab at Carnegie Mellon. Future work will investigate left-handed γPNAs in the nanomanufacturing process. For future biomedical applications, left-handed structures would be of particular interest because they would not pose a risk of binding to cellular DNA.

###

This work represents an interdisciplinary collaboration. Additional authors included chemistry Ph.D. candidate Alexander Pearse and mechanical engineering candidate Ying Liu.

Lisa Kulick | EurekAlert!
Further information:
http://dx.doi.org/10.1038/s41467-020-16759-8

More articles from Interdisciplinary Research:

nachricht A fresh twist in chiral topology
22.06.2020 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht What can maritime shipping learn from brain network science?
10.06.2020 | Technische Universität Dresden

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The spin state story: Observation of the quantum spin liquid state in novel material

New insight into the spin behavior in an exotic state of matter puts us closer to next-generation spintronic devices

Aside from the deep understanding of the natural world that quantum physics theory offers, scientists worldwide are working tirelessly to bring forth a...

Im Focus: Excitation of robust materials

Kiel physics team observed extremely fast electronic changes in real time in a special material class

In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

 
Latest News

X-ray scattering shines light on protein folding

10.07.2020 | Life Sciences

Looking at linkers helps to join the dots

10.07.2020 | Materials Sciences

Surprisingly many peculiar long introns found in brain genes

10.07.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>