Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > New nanoparticles make blood clots visible

A blood vessel (top) with ruptured atherosclerotic plaque, shown in yellow, is developing a blood clot. The nanoparticles, shown in blue and black, are targeted to a protein in the blood clot called fibrin, shown in light blue. A traditional CT image (bottom left) shows no difference between the blood clot and the calcium in the plaque, making it unclear whether this image shows a clot that should be treated. A spectral CT image (bottom right) “sees” the bismuth nanoparticles targeted to fibrin in green, differentiating it from calcium, still shown in white, in the plaque.  Wiley-VCH Verlag GmbH & Co. KGaA.
A blood vessel (top) with ruptured atherosclerotic plaque, shown in yellow, is developing a blood clot. The nanoparticles, shown in blue and black, are targeted to a protein in the blood clot called fibrin, shown in light blue. A traditional CT image (bottom left) shows no difference between the blood clot and the calcium in the plaque, making it unclear whether this image shows a clot that should be treated. A spectral CT image (bottom right) “sees” the bismuth nanoparticles targeted to fibrin in green, differentiating it from calcium, still shown in white, in the plaque. Wiley-VCH Verlag GmbH & Co. KGaA.

Abstract:
Researchers at Washington University School of Medicine in St. Louis report that they have designed nanoparticles that find clots and make them visible to a new kind of X-ray technology

By Julia Evangelou Strait

New nanoparticles make blood clots visible

St. Louis, MO | Posted on February 4th, 2011

For almost two decades, cardiologists have searched for ways to see dangerous blood clots before they cause heart attacks.

Now, researchers at Washington University School of Medicine in St. Louis report that they have designed nanoparticles that find clots and make them visible to a new kind of X-ray technology.

According to Gregory Lanza, MD, PhD, a Washington University cardiologist at Barnes-Jewish Hospital, these nanoparticles will take the guesswork out of deciding whether a person coming to the hospital with chest pain is actually having a heart attack.

"Every year, millions of people come to the emergency room with chest pain. For some of them, we know it's not their heart. But for most, we're not sure," says Lanza, a professor of medicine. When there is any doubt, the patient must be admitted to the hospital and undergo tests to rule out or confirm a heart attack.

"Those tests cost money and they take time," Lanza says.

Rather than an overnight stay to make sure the patient is stable, this new technology could reveal the location of a blood clot in a matter of hours.

Spectral CT

The nanoparticles are designed to be used with a new type of CT scanner that is capable of "seeing" metals in color. The new technology, called spectral CT, uses the full spectrum of the X-ray beam to differentiate objects that would be indistinguishable with a regular CT scanner that sees only black and white.

Lanza says the new scanner takes advantage of the same physics that astronomers use to look at the light from a star and tell what metals it contains.

"They're looking at the X-ray spectrum, and the X-ray spectrum tells them what metals are there," he says. "That's exactly what we do."

Bismuth nanoparticles

In this case, the metal in question is bismuth. Dipanjan Pan, PhD, research assistant professor of medicine, designed a nanoparticle that contains enough bismuth for it to be seen by the spectral CT scanner.

"Each nanoparticle is carrying a million atoms of bismuth," Lanza says. Since CT is a relatively insensitive imaging technique, this sheer quantity of metal is necessary for the particles to be visible to the scanner.

But bismuth is a toxic heavy metal, Pan says. It can't be injected into the body on its own. Instead, Pan used a compound made of bismuth atoms attached to fatty acid chains that can't come apart in the body. He then dissolved this compound in a detergent and encapsulated the mixture in a phospholipid membrane. Much like oil droplets suspended in a shaken vinaigrette, these particles self-assemble with the bismuth compound at the core.

As Pan showed in a mouse model, the design of the nanoparticles also allows the body to break them apart and release the inner bismuth compound in a safe form.

Once the nanoparticles carried enough bismuth to be visible to the scanner, Pan added a molecule to the particles' surface that seeks out a protein called fibrin. Fibrin is common in blood clots but is not found elsewhere in the vasculature.

"If you're having a heart attack, the lining of your coronary artery has ruptured, and a clot is forming to repair it," Lanza says. "But that clot is starting to narrow the vessel so blood can't get by. Now we have a nanoparticle that will see that clot."

A spectral CT image with the bismuth nanoparticles targeted to fibrin will provide the same information as a traditional black and white CT image, but the fibrin in any blood clots will show up in a color, such as yellow or green, solving the problem of calcium interference common to traditional CT scanners.

The spectral CT scanner used in this study is still a prototype instrument, developed by Philips Research in Hamburg, Germany. The nanoparticles have only been tested in rabbits and other animal models, but early results show success in distinguishing blood clots from calcium interference.

Saving lives

More than simply confirming a heart attack, the new nanoparticles and spectral CT scanner can show a clot's exact location.

Today, even if doctors determine the patient is having a heart attack, they can't locate the clot without admitting the patient to the cardiac catheterization lab, inserting a dye and looking for narrow plaque-filled arteries they could open with stents. But Lanza says looking for narrow arteries doesn't solve all the problems.

"The ones that have very narrow openings are not the worrisome ones," Lanza says. "We find those in the cardiac catheterization lab and we open them up."

What is worrisome is when blood is free to flow through the arteries, but there is unstable plaque on the artery wall, what Lanza calls "moderate-grade disease."

"Most people's heart attacks or strokes are from moderate-grade disease that breaks off and all of a sudden blocks an artery," Lanza says. "It's what happened to NBC newsman Tim Russert. You need something that tells you there is ruptured plaque even when the vessel isn't very narrow."

Since this nanoparticle finds and sticks to fibrin in the vessels, it would allow doctors to see problems that were previously difficult or impossible to detect.

With this imaging technique, Lanza predicts new approaches to treating coronary disease. Unstable plaque that doesn't restrict much blood flow does not require an expensive stent to prop the vessel open. Instead, Lanza foresees technologies that might act like Band-Aids, sealing weak spots in the vessel walls.

"Today, you wouldn't know where to stick the Band-Aid," Lanza says. "But spectral CT imaging with bismuth nanoparticles would show the exact location of clots in the vessels, making it possible to prevent the dangerous rupture of unstable plaque."

Pan D, Roessl E, Schlomka JP, Caruthers SD, Senpan A, Scott MJ, Allen JS, Zhang H, Hu G, Gaffney PJ, Choi ET, Rasche V, Wickline SA, Proksa R, Lanza GM. Computed Tomography in color: NanoK-enhanced spectral CT molecular imaging. Angewandte Chemie, International Edition, Dec. 10, 2010.

This work was supported by grants from the American Heart Association, National Cancer Institute, Bioengineering Research Partnership and the National Heart, Lung, and Blood Institute.

The spectral CT prototype is on loan to Washington University from Philips Research in Hamburg, Germany, for codevelopment of the scanner, software and nanoparticles.

####

About Washington University School of Medicine in St. Louis
Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked fourth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.

For more information, please click here

Contacts:
Julia Evangelou Strait
Senior Medical Sciences Writer
(314) 286-0141

Copyright © Washington University School of Medicine in St. Louis

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

Engineers develop new materials for hydrogen storage April 15th, 2014

Nanocrystalline cellulose modified into an efficient viral inhibitor April 15th, 2014

Tiny particles could help verify goods: Chemical engineers hope smartphone-readable microparticles could crack down on counterfeiting April 15th, 2014

A molecular approach to solar power: Switchable material could harness the power of the sun — even when it’s not shining April 15th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Engineers develop new materials for hydrogen storage April 15th, 2014

Tiny particles could help verify goods: Chemical engineers hope smartphone-readable microparticles could crack down on counterfeiting April 15th, 2014

A molecular approach to solar power: Switchable material could harness the power of the sun — even when it’s not shining April 15th, 2014

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

Possible Futures

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Surface Characteristics Influence Cellular Growth on Semiconductor Material March 12th, 2014

The "Tipping Point" February 12th, 2014

Academic/Education

Director Wally Pfister joins UC Berkeley neuroengineers to discuss the science behind ‘Transcendence’ April 7th, 2014

First annual science week highlights STEM pipeline and partnerships: UB, SUNY Buffalo State and ECC team up with the City of Buffalo and its schools for April 7-11 events April 3rd, 2014

Global 450 consortium announces new general manager of internal operations: TSMC’s Cheng-Chung Chien Receives Unanimous Support, Brings History of Innovation and Efficiency to Global Consortium of Companies Driving Industry Transition to 450mm Wafer Technology March 26th, 2014

NanoTecNexus to Host "Chemistry of Wine" Fundraiser in Support of STEM Education - Collaborations Key to Success - March 20th, 2014

Self Assembly

Roomy cages built from DNA: Self-assembling cages are the largest standalone 3-D DNA structures yet, and could one day deliver drugs, or house tiny bioreactors or photonic devices March 13th, 2014

Cypress’s TrueTouch® Touchscreen Controllers Compatible with Cima NanoTech’s SANTE® Silver Nanoparticle-Based Touch Sensors: Supporting Designs for Advanced Touch Applications March 5th, 2014

Coupled carbon and peptide nanotubes achieved for the first time: twins nanotubes March 1st, 2014

A potentially revolutionnary material: Scientists produce a novel form of artificial graphene February 15th, 2014

Nanomedicine

Nanocrystalline cellulose modified into an efficient viral inhibitor April 15th, 2014

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

Nano shake-up: UD researchers demonstrate that processing can affect size of nanocarriers for targeted drug delivery April 14th, 2014

Premier Healthcare Pitch Competition comes to Atlanta this May April 12th, 2014

Announcements

Tiny particles could help verify goods: Chemical engineers hope smartphone-readable microparticles could crack down on counterfeiting April 15th, 2014

A molecular approach to solar power: Switchable material could harness the power of the sun — even when it’s not shining April 15th, 2014

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

Biologists Develop Nanosensors to Visualize Movements and Distribution of Plant Stress Hormone April 15th, 2014

Grants/Awards/Scholarships/Gifts/Contests/Honors/Records

IDTechEx Printed Electronics Europe 2014 Award Winners April 1st, 2014

Dais Analytic Wins SBIR Grant: Dais Analytic Receives US Army Small Business Innovation Research Grant to Further Its Demonstrated Successes in Cleaning Most Forms of Wastewater March 28th, 2014

Scientists develop world’s first light-activated antimicrobial surface that also works in the dark March 24th, 2014

Sets new record for transparent Organic Solar Cells: Ideal for generating energy from windows, façades and glass car roofs March 24th, 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