Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > A heart of gold - New cardiac patch uses gold nanowires to enhance electrical signaling between cells, a promising step toward better treatment for heart-attack patients.

A scanning electron microscope (SEM) image of nanowire-alginate composite scaffolds. Star-shaped clusters of nanowires can be seen in these images.
Image courtesy of the Disease Biophysics Group, Harvard University
A scanning electron microscope (SEM) image of nanowire-alginate composite scaffolds. Star-shaped clusters of nanowires can be seen in these images.

Image courtesy of the Disease Biophysics Group, Harvard University

Abstract:
A team of researchers at MIT and Children's Hospital Boston has built cardiac patches studded with tiny gold wires that could be used to create pieces of tissue whose cells all beat in time, mimicking the dynamics of natural heart muscle. The development could someday help people who have suffered heart attacks.

A heart of gold - New cardiac patch uses gold nanowires to enhance electrical signaling between cells, a promising step toward better treatment for heart-attack patients.

Cambridge, MA | Posted on September 26th, 2011

The study, reported this week in Nature Nanotechnology, promises to improve on existing cardiac patches, which have difficulty achieving the level of conductivity necessary to ensure a smooth, continuous "beat" throughout a large piece of tissue.

"The heart is an electrically quite sophisticated piece of machinery," says Daniel Kohane, a professor in the Harvard-MIT Division of Health Sciences and Technology (HST) and senior author of the paper. "It is important that the cells beat together, or the tissue won't function properly."

The unique new approach uses gold nanowires scattered among cardiac cells as they're grown in vitro, a technique that "markedly enhances the performance of the cardiac patch," Kohane says. The researchers believe the technology may eventually result in implantable patches to replace tissue that's been damaged in a heart attack.

Co-first authors of the study are MIT postdoc Brian Timko and former MIT postdoc Tal Dvir, now at Tel Aviv University in Israel; other authors are their colleagues from HST, Children's Hospital Boston and MIT's Department of Chemical Engineering, including Robert Langer, the David H. Koch Institute Professor.

Ka-thump, ka-thump

To build new tissue, biological engineers typically use miniature scaffolds resembling porous sponges to organize cells into functional shapes as they grow. Traditionally, however, these scaffolds have been made from materials with poor electrical conductivity and for cardiac cells, which rely on electrical signals to coordinate their contraction, that's a big problem.

"In the case of cardiac myocytes in particular, you need a good junction between the cells to get signal conduction," Timko says. But the scaffold acts as an insulator, blocking signals from traveling much beyond a cell's immediate neighbors, and making it nearly impossible to get all the cells in the tissue to beat together as a unit.

To solve the problem, Timko and Dvir took advantage of their complementary backgrounds Timko's in semiconducting nanowires, Dvir's in cardiac-tissue engineering to design a brand-new scaffold material that would allow electrical signals to pass through.

"We started brainstorming, and it occurred to me that it's actually fairly easy to grow gold nanoconductors, which of course are very conductive," Timko says. "You can grow them to be a couple microns long, which is more than enough to pass through the walls of the scaffold."

From micrometers to millimeters

The team took as their base material alginate, an organic gum-like substance that is often used for tissue scaffolds. They mixed the alginate with a solution containing gold nanowires to create a composite scaffold with billions of the tiny metal structures running through it.

Then, they seeded cardiac cells onto the gold-alginate composite, testing the conductivity of tissue grown on the composite compared to tissue grown on pure alginate. Because signals are conducted by calcium ions in and among the cells, the researchers could check how far signals travel by observing the amount of calcium present in different areas of the tissue.

"Basically, calcium is how cardiac cells talk to each other, so we labeled the cells with a calcium indicator and put the scaffold under the microscope," Timko says. There, they observed a dramatic improvement among cells grown on the composite scaffold: The range of signals conduction improved by about three orders of magnitude.

"In healthy, native heart tissue, you're talking about conduction over centimeters," Timko says. Previously, tissue grown on pure alginate showed conduction over only a few hundred micrometers, or thousandths of a millimeter. But the combination of alginate and gold nanowires achieved signal conduction over a scale of "many millimeters," Timko says.

"It's really night and day. The performance that the scaffolds have with these nanomaterials is just much, much better," Kohane says.

Written by Emily Finn, MIT News Office

####

For more information, please click here

Contacts:
Marta Buczek
MIT News Office
E:
T: 617.253.2702

Copyright © MIT

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

Study finds long-term survival of human neural stem cells transplanted into primate brain April 23rd, 2014

High-Performance, Low-Cost Ultracapacitors Built with Graphene and Carbon Nanotubes: Future devices based on technology could bridge gap between batteries and conventional capacitors in portable electronics and hybrid electric vehicles April 23rd, 2014

Guo Lab Shows Potential of RNA as Heat-resistant Polymer Material for Nanoarchitectures April 23rd, 2014

National Space Society Congratulates SpaceX on the Success of CRS-3 and the First Flight of the Falcon 9R April 22nd, 2014

Nanomedicine

Study finds long-term survival of human neural stem cells transplanted into primate brain April 23rd, 2014

Cloaked DNA nanodevices survive pilot mission: Successful foray opens door to virus-like DNA nanodevices that could diagnose diseased tissues and manufacture drugs to treat them April 22nd, 2014

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

Amino-functionalized carbon nanotubes act as a carrier for nerve growth factor April 21st, 2014

Discoveries

Study finds long-term survival of human neural stem cells transplanted into primate brain April 23rd, 2014

High-Performance, Low-Cost Ultracapacitors Built with Graphene and Carbon Nanotubes: Future devices based on technology could bridge gap between batteries and conventional capacitors in portable electronics and hybrid electric vehicles April 23rd, 2014

Guo Lab Shows Potential of RNA as Heat-resistant Polymer Material for Nanoarchitectures April 23rd, 2014

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

Announcements

Study finds long-term survival of human neural stem cells transplanted into primate brain April 23rd, 2014

High-Performance, Low-Cost Ultracapacitors Built with Graphene and Carbon Nanotubes: Future devices based on technology could bridge gap between batteries and conventional capacitors in portable electronics and hybrid electric vehicles April 23rd, 2014

Guo Lab Shows Potential of RNA as Heat-resistant Polymer Material for Nanoarchitectures April 23rd, 2014

National Space Society Congratulates SpaceX on the Success of CRS-3 and the First Flight of the Falcon 9R April 22nd, 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