Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > New technique sees into tissue at greater depth, resolution

Abstract:
By coupling a kicked-up version of microscopy with miniscule particles of gold, Duke University scientists are now able to peer so deep into living tissue that they can see molecules interacting.

New technique sees into tissue at greater depth, resolution

DURHAM, NC | Posted on September 17th, 2008

If future studies in animal models prove fruitful, the researchers believe that their new approach can have a wide spectrum of clinical applications, from studying the margins of a tumor as it is removed from the body to assessing the effects of anti-cancer agents on the blood vessels that nourish tumors.

The Duke bioengineers combined tightly focused heat with optical coherence tomography (OCT), which has often been called the optical equivalent of ultrasound. OCT is commonly used in medical clinics where imaging at the highest resolution is critical, such as in the retina. These experiments represent the first time the technique has been extended to the functional imaging of cells expressing particular molecular receptors.

"This technique could possibly augment traditional methods of deep-tissue molecular imaging with a relatively high resolution," said Melissa Skala, a postdoctoral fellow working in the laboratory of Joseph Izatt, professor of biomedical engineering in Duke's Pratt School of Engineering. "Not only were we able to get better images, we were able to specifically target the types of cells we were looking for."

The results of the Duke research were posted on line by Nano Letters, a journal published by the American Chemical Society. The research was supported by the National Institutes of Health.

For their experiments, the Duke team attached nanospheres of gold to a targeting molecule known as a monoclonal antibody.

Gold is a metal that not only is an efficient conductor of heat, but whose effects in the body are well known. The antibody they used targets epidermal growth factor receptor (EGFR), a cell-surface receptor implicated in cancer.

These "tagged" antibodies were then applied to the surface of a three-dimensional tissue model composed of human cells - both cancerous and non-cancerous. Skala hoped that these antibodies would home in on cells that were overproducing EGFR on their surfaces, an indicator of cancerous activity. Then the photothermal OCT would be able to detect them by showing where the gold spheres were concentrated.

"When we directed the photothermal OCT at the tissue, we found that the cells that were overexpressing EGFR gave off a signal 300 percent higher than cells with low expressions of EGFR," Skala said.

Adding heat to this form of microscopy technique created a phenomenon much like that seen on very hot days, when portions of the pavement far in the distance seem to float or hover above the road.

"The heat causes a distortion in the way light is reflected off the gold nanospheres in a characteristic way," Skala explained. "As we changed the temperature, the light pathways would change in measurable ways."

In this manner, Skala explained, they were not only able to "see" cells within the tissue, but they were able to capture the molecular function of an antibody attaching to a receptor.

"The use of metal nanoparticles as contrast agents with photothermal OCT technology could lead to a host of potential clinical applications," Izatt said. "Organically-based contrast agents can cause damage or death to the targeted cells, while metal nanospheres are relatively safer."

"Also, given the wide range of nanoparticle shapes and sizes, coupled with the ability to 'tune" the optical wavelength of the OCT, we can customize our approach to many different target types," Izatt said.

Skala plans to expand the use of this approach in animal models to better understand the role of different cancer therapies. Tumors with elevated levels of EGFR are known to have a poor prognosis, and she plans to use photothermal OCT to measure how these tumor types react to different therapies.

Other members of the Duke team were Adam Wax, professor of biomedical engineering and his graduate student Matthew Crow. Skala also worked with Mark Dewhirst, a cancer researcher at Duke University Medical Center, and plans further collaborations with the Dewhirst laboratory to apply this technique better understand the fundamentals of cancer.

####

For more information, please click here

Contacts:
Richard Merritt

919-660-8414

Copyright © Duke 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

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Chemical trickery corrals 'hyperactive' metal-oxide cluster December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Exotic insulator may hold clue to key mystery of modern physics: Johns Hopkins-led research shows material living between classical and quantum worlds December 8th, 2016

Imaging

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Controlled electron pulses November 30th, 2016

Academic/Education

Oxford Nanoimaging report on how the Nanoimager, a desktop microscope delivering single molecule, super-resolution performance, is being applied at the MRC Centre for Molecular Bacteriology & Infection November 22nd, 2016

The University of Applied Sciences in Upper Austria uses Deben tensile stages as an integral part of their computed tomography research and testing facility October 18th, 2016

Enterprise In Space Partners with Sketchfab and 3D Hubs for NewSpace Education October 13th, 2016

New Agricultural Research Center Debuts at UCF October 12th, 2016

Discoveries

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Researchers peer into atom-sized tunnels in hunt for better battery: May improve lithium ion for larger devices, like cars December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Announcements

Keeping electric car design on the right road: A closer look at the life-cycle impacts of lithium-ion batteries and proton exchange membrane fuel cells December 9th, 2016

Further improvement of qubit lifetime for quantum computers: New technique removes quasiparticles from superconducting quantum circuits December 9th, 2016

Researchers peer into atom-sized tunnels in hunt for better battery: May improve lithium ion for larger devices, like cars December 8th, 2016

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Tools

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D: Up-close, real-time, chemical-sensitive 3-D imaging offers clues for reducing cost/improving performance of catalysts for fuel-cell-powered vehicles and other applications December 8th, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Controlled electron pulses November 30th, 2016

Scientists shrink electron gun to matchbox size: Terahertz technology has the potential to enable new applications November 25th, 2016

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