Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Bendy tubes get around

Abstract:
Rice-led researchers settle argument over mobility of flexible filaments

Bendy tubes get around

Houston, TX | Posted on January 5th, 2011

Theo Odijk, you win. The professor of biotechnology at Delft University of Technology in the Netherlands has a new best friend in Rice University's Matteo Pasquali.

Together with collaborators at the French National Center for Scientific Research (CNRS), the University of Bordeaux, France, and Vrije University, Amsterdam, the Rice professor and his team have settled a long-standing controversy in the field of polymer dynamics: The researchers proved once and for all that Odijk was correct in proclaiming that a little flexibility goes a long way for stiff filaments in a solution.

The study in the current issue of the journal Science shows that even a small ability to bend gives nanotubes and other tiny, stiff filaments the means to navigate through crowded environments, or even such fixed networks as cell matrices.

The work by Pasquali, a professor in chemical and biomolecular engineering and in chemistry, may bring about new ways to influence the motion of tiny filaments by tailoring their stiffness for a given environment.

Nanotubes are being studied for potential use in all kinds of sensing, even in the seemingly disparate fields of biological applications and oil exploration. In both, the ability of nanotubes and other fine, filamentous particles to move through their environments is critical, Pasquali said.

Understanding the motion of a single, flexible polymer chain in a network has been key to scientific advances by Odijk and others on, for example, the behavior of DNA. The Rice researchers expect their revelation to have no less impact.

Pasquali and lead author Nikta Fakhri, a former graduate student at Rice now doing postdoctoral research at the University of Gottingen, Germany, set out to break the deadlocked theories by Odijk and two other scientists who disagreed on the Brownian motion of stiff filaments in a crowded environment, and whether stiffness itself played any part.

"There's a long-standing, fundamental question: How does this threadlike object move when it gets crowded? It could be crowded because it's in a gel, or because there are a lot of threadlike objects with it -- which to that one object looks like a gel," he said.

Crowding constrains the ability of a filament to travel. Think of trying to get from the back to the front of a crowded bus; it takes a certain amount of agility to weave your way through the packed bodies. "It turns out that with a little flexibility, a filament can explore the space around it much more effectively," Pasquali said.

That becomes important when the goal is to get filaments to find and enter a cellular pore to deliver a dose of medication or to act as a fluorescent sensor.

"If you look at the human body, they say we're made of 60 percent water, but we don't slosh around," Pasquali explained. "That's because the water is trapped in pores. Almost all the water in our body is in gel-like structures: inside our cells, which are laden with filamentous networks, or in the interstitial fluid surrounding these cells. We are a big, squishy, porous medium. We need to understand how the nanoparticles move in this medium."

Pasquali and Fakhri mimicked biological networks by using varying concentrations of agarose gel, a porous material often used as a filter in biochemistry and molecular biology for DNA and proteins. The gel forms a matrix of controllable size through which molecules can move.

Nanotubes served as a stand-in for any type of filament, albeit one whose stiffness can be controlled. Like a PVC pipe in the macro world, nanotubes get stiffer as they get thicker; but even the stiffest tubes can flex a bit with length, and these tubes were thousands of times longer than they were wide.

The study started somewhat serendipitously when co-author Laurent Cognet, a researcher at CNRS and the University of Bordeaux, tried to immobilize nanotubes in agarose gels. He noticed in a failed experiment that the nanotubes moved in a "funny way" and discussed it with Pasquali.

Pasquali asked whether the nanotubes were reptating -- scientist lingo for a snakelike motion -- and Cognet said yes. Fakhri, who was studying the dynamics of nanotubes, traveled to the Bordeaux laboratory of Cognet and co-author Brahim Lounis to capture images of the nanotubes in motion.

The resulting spectroscopic and direct still and video images of 35 fluorescent single-walled nanotubes showed them snaking through the gel, probing pores and paths. The nanotubes, like all filaments, obeyed the rules of thermal-induced Brownian motion; they were pushed and pulled by the ever-changing states of the molecules around them.

The research established that flexibility significantly enhances the nanotubes' ability to navigate around obstacles and speeds up their exploration.

Pasquali said Fakhri doggedly pursued her analysis of the nanotubes' motion through computerized image recognition and motion tracking, as well as old-fashioned pencil-and-paper dynamical analysis. He said his longtime collaborator, co-author Frederick MacKintosh, a theoretical physicist at Vrije University, was a tremendous help. MacKintosh has been studying the dynamics of biological networks for nearly two decades.

Pasquali intends to replace the gel with real rocks to see how nanotubes, which can be used as oil-detecting sensors, move in a more structured environment. "Rocks can be a little more complicated," he said. "The question here is, what can nanotubes do better than nanoparticles? The answer may be that slender nanotubes may interact with electromagnetic fields more strongly than other nanoparticles of the same volume."

The National Science Foundation Center for Biological and Environmental Nanotechnology, the Welch Foundation, the Advanced Energy Consortium, the Région Aquitaine, the Agence National pour la Recherche, the European Research Council and the Dutch Foundation for Fundamental Research on Matter supported the work.

Read the abstract at www.sciencemag.org/content/330/6012/1804.abstract

A video of a reptating nanotube can be viewed at www.sciencemag.org/content/330/6012/1804/suppl/DC1

####

About Rice University
Located in Houston, Rice University is consistently ranked one of America's best teaching and research universities. Known for its "unconventional wisdom," Rice is distinguished by its: size -- 3,279 undergraduates and 2,277 graduate students; selectivity -- 12 applicants for each place in the freshman class; resources -- an undergraduate student-to-faculty ratio of 5-to-1; sixth largest endowment per student among American private research universities; residential college system, which builds communities that are both close-knit and diverse; and collaborative culture, which crosses disciplines, integrates teaching and research, and intermingles undergraduate and graduate work.

For more information, please click here

Contacts:
David Ruth
713-348-6327


Mike Williams
713-348-6728

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

3rd Iran-Proposed Nano Standard Approved by International Standard Organization November 22nd, 2014

NMTI announces breakthrough solutions for HAMR nanoantenna for next-generation ultra-high density magnetic storage November 21st, 2014

Sustainable Nanotechnologies Project November 20th, 2014

Quantum mechanical calculations reveal the hidden states of enzyme active sites November 20th, 2014

Videos/Movies

Purdue 3-D printing innovation capable of making stronger, lighter metal works for auto, aerospace industries November 20th, 2014

New way to move atomically thin semiconductors for use in flexible devices November 13th, 2014

A billion holes can make a battery November 10th, 2014

Manipulating complex molecules by hand: New method in scanning probe microscopy: Jülich researchers create a word using 47 molecules November 6th, 2014

Govt.-Legislation/Regulation/Funding/Policy

3rd Iran-Proposed Nano Standard Approved by International Standard Organization November 22nd, 2014

NMTI announces breakthrough solutions for HAMR nanoantenna for next-generation ultra-high density magnetic storage November 21st, 2014

Sustainable Nanotechnologies Project November 20th, 2014

Quantum mechanical calculations reveal the hidden states of enzyme active sites November 20th, 2014

Possible Futures

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Researchers discern the shapes of high-order Brownian motions November 17th, 2014

VDMA Electronics Production Equipment: Growth track for 2014 and 2015 confirmed: Business climate survey shows robust industry sector November 14th, 2014

Open Materials Development Will Be Key for HP's Success in 3D Printing: HP can make a big splash in 3D printing, but it needs to shore up technology claims and avoid the temptation of the razor/razor blade business model in order to flourish November 11th, 2014

Academic/Education

SUNY Poly Student Awarded Fellowship with the U.S. Department of Energy's Postgraduate Research Program: Ph.D. Candidate Accepts Postmaster's Appointment To Conduct Research At Albany NanoTech Complex November 13th, 2014

SUNY Polytechnic Institute Hosts Massive Crowd of More Than 3,000 People Who Attended Community Day Activities Across New York State: CNSE’s ‘NANOvember’ kickoff event highlights New York State’s growing high-tech sector with open house events in Albany, Utica, and Rochester November 3rd, 2014

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

First Canada Excellence Research Chair gets $10 million from the federal government for oilsands research at the University of Calgary: Federal government announces prestigious research chair to study improving oil production efficiency October 19th, 2014

Nanotubes/Buckyballs

Tesla NanoCoatings Increasing Use of SouthWest NanoTechnologies Carbon Nanotubes (CNTs) for its Infrastructure Coatings and Paints: High Quality SMW™ Specialty Multi-wall Carbon Nanotubes Incorporated into Teslan®-brand coatings used by Transportation, Oil and Gas Companies November 19th, 2014

Graphene/nanotube hybrid benefits flexible solar cells: Rice University labs create novel electrode for dye-sensitized cells November 17th, 2014

SouthWest NanoTechnologies to Demonstrate 3D Capacitive Touch Sensor Featuring Transparent, Thermoformed Carbon Nanotube Ink at Printed Electronics USA 2014 (Booth J25) -- “Conductive and Semiconducting Single-Wall Carbon Nanotube Inks” will be Topic of Company Presentation November 10th, 2014

Neural Canals Produced in Iran for Recovery of Sciatica Nerve November 8th, 2014

Sensors

Canatu Launches CNB In-Mold Film for Transparent Touch on 3D Surfaces –in Cars, Household Appliances, Wearables, Portables November 20th, 2014

UO-industry collaboration points to improved nanomaterials: University of Oregon microscope puts spotlight on the surface structure of quantum dots for designing new solar devices November 20th, 2014

Spiraling light, nanoparticles and insights into life’s structure November 19th, 2014

New materials for more powerful solar cells: Major breakthrough in solar energy November 11th, 2014

Announcements

3rd Iran-Proposed Nano Standard Approved by International Standard Organization November 22nd, 2014

NMTI announces breakthrough solutions for HAMR nanoantenna for next-generation ultra-high density magnetic storage November 21st, 2014

Silver Nanoparticles Produced in Iran from Forest Plants Extract November 20th, 2014

Nano Sorbents Able to Remove Pollutions Caused by Oil Derivatives November 20th, 2014

Research partnerships

Quantum mechanical calculations reveal the hidden states of enzyme active sites November 20th, 2014

UO-industry collaboration points to improved nanomaterials: University of Oregon microscope puts spotlight on the surface structure of quantum dots for designing new solar devices November 20th, 2014

NRL Scientists Discover Novel Metamaterial Properties within Hexagonal Boron Nitride November 20th, 2014

First genetic-based tool to detect circulating cancer cells in blood: NanoFlares light up individual cells if breast cancer biomarker is present November 17th, 2014

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More












ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE