Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UC Santa Barbara researchers discover living nanoscale ’necklace’

09.11.2004


In an interdisciplinary endeavor at the University of California, Santa Barbara, a team of researchers in physics and biology have made a discovery at the nanoscale level that could be instrumental in the production of miniaturized materials with many applications. Dubbed a "living necklace," the finding was completely unexpected.

This discovery could influence the development of vehicles for chemical, drug, and gene delivery, enzyme encapsulation systems and biosensors, circuitry components, as well as templates for nanosized wires and optical materials. The findings are reported in the November 16 issue of the Proceedings of the National Academy of Sciences and published online the week of November 8.

The collaborating labs are those of Cyrus Safinya, professor of materials and physics and faculty member of the Biomolecular Science & Engineering Program, and Leslie Wilson, professor of biochemistry in the Department of Molecular, Cellular and Developmental Biology. The first author of the paper is Safinya’s graduate student Daniel Needleman. Postdoctoral researchers Uri Raviv and Miguel Ojeda-Lopez from Safinya’s group and Herbert Miller, a researcher in Wilson’s group, completed the team.



The scientists studied microtubules from the brain tissue of a cow to understand the mechanisms leading to their assembly and shape. Microtubules are nanometer-scale hollow cylinders derived from cell cytoskeleton. In an organism, microtubules and their assembled structures are critical components in a broad range of cell functions -- from providing tracks for the transport of cargo to forming the spindle structure in cell division. Their functions include the transport of neurotransmitters in neurons. The mechanism of their assembly within an organism has been poorly understood.

In the paper, the researchers report the discovery of a new type of higher order assembly of microtubules. Positively-charged large, linear molecules (tri-, tetra- and penta-valent cations) resulted in a tightly bundled hexagonal grouping of microtubules – a result that was predicted. But unexpectedly, the scientists found that small, spherical divalent cations caused the microtubules to assemble into a "necklace." They discovered distinct linear, branched and loop shaped necklaces.

Safinya and Needleman commented that from a formal theoretical physics perspective, the living necklace phase is the first experimental realization of a new type of membrane where the long microtubule molecules are oriented in the same direction but can diffuse within the living membrane. They explained that the living necklace bundle is highly dynamic and that thermal fluctuations will cause it to change shape.

The scientists envision applications based on both the tight bundle and living necklace phases. For example, metallization of necklace bundles with different sizes and shapes would yield nanomaterials with controlled optical properties.

A more original application is in the area of using the assemblies – encased by a lipid bilayer – as drug or gene carriers where each nanotube may contain a distinct chemical, as noted by the team. In delivery applications the shape of the bundle determines its property. For example, the linear necklace phase with its higher surface to volume ratio would have a larger contact area and a faster delivery rate compared to the tight bundle phase.

The work was performed using state-of-the-art synchrotron x-ray scattering techniques at the Stanford Synchrotron Radiation Laboratory combined with sophisticated electron and optical microscopy at UCSB.

Gail Gallessich | EurekAlert!
Further information:
http://www.ucsb.edu

More articles from Interdisciplinary Research:

nachricht Bergamotene - alluring and lethal for Manduca sexta
21.04.2017 | Max-Planck-Institut für chemische Ökologie

nachricht How to color a lizard: From biology to mathematics
13.04.2017 | Université de Genève

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>