Subscribe free to our newsletters via your
. 24/7 Space News .


Subscribe free to our newsletters via your




















Nanoshells Simultaneously Detect And Destroy Cancerous Cells

About 1/20th the size of a red blood cell, nanoshells (illustrated above) are about the size of a virus. They are ball-shaped and consist of a core of non-conducting glass that is covered by a metallic shell, typically either gold or silver. Discovered by Halas at Rice in the 1990s, nanoshells are already being developed for applications including cancer diagnosis, cancer therapy, diagnosis and testing for proteins associated with Alzheimer's disease, drug delivery and rapid whole-blood immunoassay.
Houston TX (SPX) Apr 14, 2005
Researchers at Rice University in Texas have developed a new approach to fighting cancer, based on nanoscale particles that can both detect and destroy cancerous cells.

The report appears in the April 13 issue of the American Chemical Society's journal Nano Letters.

Current molecular imaging approaches only detect the cancer but don't offer a method of treatment, according to the study's lead authors, Rebekah Drezek, Ph.D., and Jennifer West, Ph.D., both professors in the Department of Bioengineering at Rice.

"You can look for a molecular marker that may indicate a significant clinical problem, but you can't do anything about it (just through imaging)," says Drezek.

"We don't want to simply find the cancerous cells. We would like to locate the cells, be able to make a rational choice about whether they need to be destroyed and, if so, proceed immediately to treatment."

To this end, Drezek and West collaborated to develop a new imaging and treatment method based on metal "nanoshells" - tiny spheres of silica coated with a thin layer of gold.

Nanoshells were invented by electrical engineer Naomi Halas, Ph.D., also of Rice University.

Because these spheres are constructed on the nanometer scale (one billionth of a meter, the range where molecular interactions take place), they exhibit unique size-dependent behavior, such as tunable optical properties.

This allows researchers to design particles that scatter and absorb light at particular wavelengths.

The scattering of light provides the optical signal used to detect the cancer cells, which then "light up" when they come into contact with the nanoshells.

In this study, the researchers designed the nanoshells to look for breast cancer biomarkers on the surface of the cancer cells.

The technique can be readily extended to target other types of cancer or disease processes that have known surface markers.

The additional ability of the particles to absorb light is used to generate heat, which then destroys the cancer cells.

"Nanoshells are very unique in that we can engineer the particles so that both the optical scattering and absorption peaks occur in the near-infrared (NIR) spectral region where light penetration through tissue is highest," Drezek says.

The NIR absorption also makes destruction of the targeted cells less invasive for patients because it uses a light source from outside the body that passes harmlessly through normal tissue and only heats the tissue containing nanoshells.

The new approach has some significant advantages over other alternatives that are under development, according to Drezek.

For instance, optical imaging is much faster and less expensive than other medical imaging techniques. Gold nanoparticles are also more biocompatible than other types of optically active nanoparticles, such as quantum dots.

Gold is a chemically inert material that is well-known for its biocompatibility, which is why it has found use in a variety of medical applications in the past.

"There is a prior history of the use of gold inside the body that makes the safety issues somewhat easier to address," Drezek says.

Of course, any new technology requires extensive safety assessment before coming to market, but initial results from nanoshells testing are promising.

Nanoshells developed for therapeutic applications have already been evaluated by Nanospectra Biosciences, the Houston-based company that is commercializing the technology, with no ill effects found, according to Drezek.

Drezek and West have successfully tested the separate imaging and therapy aspects of the nanoshells in animals and are now evaluating the combined imaging/therapy nanoshells in a mouse tumor model, which they expect to complete within the next six months.

Related Links
American Chemical Society
Rice University in Texas
SpaceDaily
Search SpaceDaily
Subscribe To SpaceDaily Express

Remote Control Insects
Moffett Field CA (SPX) Apr 11, 2005
Yale University School of Medicine researchers have found a way to exercise a little mind control over fruit flies, making the flies jump, beat their wings, and fly on command by triggering genetic "remote controls" that the scientists designed and installed in the insects' central nervous systems, according to a new report in the 8 April issue of the journal Cell.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only






Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News








The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.