Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

DWI scientists program the lifetime of self-assembled nanostructures

08.04.2015

Materials that self-assemble and self-destruct once their work is done are highly advantageous for a number of applications – as components in temporary data storage systems or for medical devices. For example, such materials could seal blood vessels during surgery and re-open them subsequently.

Dr. Andreas Walther, research group leader at DWI – Leibniz Institute for Interactive Materials in Aachen, developed an aqueous system that uses a single starting point to induce self-assembly formation, whose stability is pre-programmed with a lifetime before disassembly occurs without any additional external signal – hence presenting an artificial self-regulation mechanism in closed conditions.


Scientists at DWI can program self-assembly, lifetime and degradation of nanostructures, consisting of single polymer strands.

Image: Thomas Heuser / DWI

Biologically inspired principles for synthesis of complex materials are one of Andreas Walther’s key research interests. To allow the preparation of very small, elaborate objects, nanotechnology uses self-assembly.

Usually, in man-made self-assemblies, molecular interactions guide tiny building blocks to aggregate into 3D architectures until equilibrium is reached. However, nature goes one step further and prevents certain processes from reaching equilibrium.

Assembly competes with disassembly, and self-regulation occurs. For example, microtubules, components of the cytoskeleton, continuously grow, shrink and rearrange. Once they run out of their biological fuel, they will disassemble.

This motivated Andreas Walther and his team to develop an aqueous, closed system, in which the precise balance between assembly reaction and programmed activation of the degradation reaction controls the lifetime of the materials.

A single starting injection initiates the whole process, which distinguishes this new approach from current responsive systems that always require a second signal to trigger the disassembly.

The approach uses pH changes to control the process. The scientists press the start button by adding a base and a dormant deactivator.

This first rapidly increases the pH and the building blocks – block copolymers, nanoparticles or peptides – then assemble into a three-dimensional structure. At the same time, the change of pH stimulates the dormant deactivator.

PhD student Thomas Heuser explains: “The dormant deactivator slowly becomes activated and triggers an off-switch. But it takes a while before the off-switch unfolds its full potential. Depending on the molecular structure of the deactivator, this can be minutes, hours or a whole day. Until then, the self-assembled nanostructures remain stable.”

Currently a hydrolytic reaction is used to activate the dormant deactivator. However, Andreas Walther and his team are already working on more sophisticated versions, which include an enzymatic reaction to slowly start the self-destruction mechanism.

Weitere Informationen:

http://pubs.acs.org/doi/abs/10.1021/nl5039506

Dr. Janine Hillmer | idw - Informationsdienst Wissenschaft
Further information:
http://www.dwi.rwth-aachen.de

More articles from Life Sciences:

nachricht Cells communicate in a dynamic code
19.02.2018 | California Institute of Technology

nachricht Studying mitosis' structure to understand the inside of cancer cells
19.02.2018 | Biophysical Society

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Contacting the molecular world through graphene nanoribbons

19.02.2018 | Materials Sciences

When Proteins Shake Hands

19.02.2018 | Materials Sciences

Cells communicate in a dynamic code

19.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>