Nanotechnology Now

Our NanoNews Digest Sponsors







Heifer International

Wikipedia Affiliate Button


Home > Press > Liquid or solid? Charged nanoparticles in lipid membrane decide

Abstract:
Like water and ice cubes mixed in a glass, a group of organic compounds called lipids can coexist as liquid and solid in membranes. This patchiness in phospholipid membranes is fundamental to their use as biomolecules and biosensors.

Using charged nanoparticles, researchers at the University of Illinois have found a new way to stimulate patchiness in phospholipid membranes.

Liquid or solid? Charged nanoparticles in lipid membrane decide

Champaign, IL | Posted on November 11th, 2008

"We are seeing a previously unsuspected responsiveness in phospholipid membranes," said Steve Granick, a Founder Professor of Engineering at the U. of I. "What we thought was possible only with the specificity of certain proteins, we now see can happen with simple, charged nanoparticles."

Lipids are the building blocks of cell membranes. In earlier work, Granick and graduate student Liangfang Zhang found a way to stabilize sensitive lipid membranes by attaching charged nanoparticles to the membrane surface.

Now, Granick, Zhang, graduate research assistant Bo Wang and research scientist Sung Chul Bae show that a phospholipid membrane can coexist in two phases - solid and liquid - according to what binds to it. This inherent patchiness presents an additional mechanism for changing the stiffness of phospholipid membranes.

The researchers report their work in a paper to be published next week in the Online Early Edition of the Proceedings of the National Academy of Sciences.

Using fluorescence and calorimetry methods, the researchers studied interactions between charged nanoparticles and membranes formed from single-component lipids. Because the membrane was composed of one sole lipid type, the traditional explanation for spatial patchiness - an uneven distribution of different lipids - was eliminated.

While a variety of nanoparticles was used, the most common type was polystyrene spheres about 20 nanometers in diameter (a nanometer is 1 billionth of a meter). Where the nanoparticles attached to the membrane, the membrane responded by changing phase.

"The electric charge acted as a switch," Granick said. "Nanoparticles with a negative charge switched membranes from liquid to solid. Nanoparticles with a positive charge switched the membranes from solid to liquid."

Phase changes occurred in patches of membranes where phospholipid molecules swiveled after binding to charged nanoparticles. This binding-induced behavior, where the same lipid can coexist in two different phases, offers a new mechanism for modulating stiffness in membranes.

In future work, the researchers plan to study the effects of smaller, charged nanoparticles; the effects of charged nanoparticles on living cells; and novel ways to stabilize lipid membranes for targeted drug delivery.

"These experiments are helping us better understand both the structure of phospholipid membranes and the potential biological effects of exposure to nanoparticles found in our normal, everyday environment," Granick said.

Granick also is a professor of materials science and engineering, of chemistry, of chemical and biomolecular engineering, and of physics; and he is a researcher at the university's Frederick Seitz Materials Research Laboratory and at the Beckman Institute.

The U.S. Department of Energy funded the work.

####

For more information, please click here

Contacts:
James E. Kloeppel

217-244-1073

Copyright © University of Illinois at Urbana-Champaign

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

How do cold ions slide May 24th, 2013

Heinrich Rohrer dies at 79; a father of nanotechnology: With IBM colleague Gerd Binnig, Rohrer invented the scanning tunneling microscope, which can show individual atoms on a surface and move them around May 23rd, 2013

Gold nanocrystal vibration captured on billion-frames-per-second film May 23rd, 2013

Glowing Plant Releases Maker Kit, Enabling Anyone to Make a Glowing Plant at Home: Glowing Plant seeks funds via crowdfunding and raises almost $400,000 May 23rd, 2013

Discoveries

How do cold ions slide May 24th, 2013

Gold nanocrystal vibration captured on billion-frames-per-second film May 23rd, 2013

Whirlpools on the Nanoscale Could Multiply Magnetic Memory: At the Advanced Light Source, Berkeley Lab scientists join an international team to control spin orientation in magnetic nanodisks May 22nd, 2013

Bacterial spare parts filter antibiotic residue from groundwater May 22nd, 2013

Announcements

How do cold ions slide May 24th, 2013

Heinrich Rohrer dies at 79; a father of nanotechnology: With IBM colleague Gerd Binnig, Rohrer invented the scanning tunneling microscope, which can show individual atoms on a surface and move them around May 23rd, 2013

Gold nanocrystal vibration captured on billion-frames-per-second film May 23rd, 2013

Glowing Plant Releases Maker Kit, Enabling Anyone to Make a Glowing Plant at Home: Glowing Plant seeks funds via crowdfunding and raises almost $400,000 May 23rd, 2013

Safety-Nanoparticles/Risk management

Conference Scheduled June 5-7 on Safe Use of Nanotechnology in Environmental Remediation May 23rd, 2013

NIA Public Briefing: Nanotechnology and the Council of Europe May 17th, 2013

Squishy hydrogels may be the ticket for studying biological effects of nanoparticles May 15th, 2013

Ubiquitous engineered nanomaterials cause lung inflammation, study finds: Substances are used in everything from paint to sporting equipment May 6th, 2013

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








abbigliamento uomo
Computer Accessories
© Copyright 1999-2013 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE