Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


DWI scientists program the lifetime of self-assembled nanostructures


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:

Dr. Janine Hillmer | idw - Informationsdienst Wissenschaft
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>