Featured Research

from universities, journals, and other organizations

A loose grip provides better chemotherapy

Date:
February 5, 2011
Source:
Case Western Reserve University
Summary:
Researchers have found that cancer patients may get a bigger bang and fewer side effects with a new take on a drug delivery system. By using noncovalent bonds to link light-activated anti-cancer drugs to coated gold nanoparticles, they were able to activate treatment in two hours instead of two days. The scientists expect the targeted delivery system will cut dosage by a factor of 10 or more.

Researchers at Case Western Reserve University have developed a little bomb that promises a big bang for cancer patients.

Preliminary tests show an anti-cancer drug loosely attached to gold nanoparticles starts accumulating deep inside tumors within minutes of injection and can be activated for an effective treatment within two hours. The same drug injected alone takes two days to gather and attacks the tumor from the surface -- a far less effective route.

The work, titled "Deep Penetration of a PDT Drug into Tumors by Noncovalent Drug-Gold Nanoparticle Conjugates," is published February 4 in the online edition of the Journal of the American Chemical Society.

Speeding anti-cancer drugs directly into tumors enables patients to receive lower doses of the toxic chemicals, thereby saving healthy tissue from damage and other harsh side effects suffered in traditional chemotherapy.

"We hope to lower the dosage by at least a factor of 10," said Clemens Burda, a professor of chemistry at Case Western Reserve and the senior author of the paper.

The key to success? The scientists tied an anti-cancer drug to golden missiles using a weak chemical interaction called a noncovalent bond. In molecule construction, a covalent bond is a heavy rope lashed and knotted; a noncovalent bond is a shoestring tied in a bow.

"Very often, additions to chemical systems change properties of the components of the system," Burda said. Attempts by his and other research groups to use covalent bonds for drug delivery have resulted in such complications and less than hoped-for results.

The researchers, who come from a breadth of disciplines, found that by using a noncovalent bond to attach the drug to coated gold, they eliminated interference among the desired properties of each component.

Burda's group sought to simplify the process by using materials that have well-known properties.

Gold nanoparticles have large surface areas that permit packing a lot in a tiny space. The element is inert inside the body and at less than 5 nanometers across, or less than 1/10,000 the width of a human hair, the particles quickly flow out of the blood stream and across cancer cell membranes to accumulate inside tumors.

A coat of polyethylene glycol links tightly to the gold while providing cargo space to attach other materials.

The coated gold provides an environment to physically prevent activation of the photodynamic therapy drug silicon phthalocyanine, preventing unintended toxic exposures to healthy tissues.

The loosely-held drug is released from the nanoparticle through the attraction of the drug to the lipid membrane of cancer cells. Laser light switches on the freed silicon phthalocyanine, which breaks down and kills cancer cells, shrinking the tumor.

After delivering the drug, the nanoparticles pass through the kidneys and clear the body within a week.

Burda teamed with Yu Cheng, Joseph D. Meyers, Ann-Marie Broome, Malcolm E. Kenney and James Basilion, all of Case Western Reserve.

Their work received a $1.2 million grant from the National Institutes of Health late this fall, to continue development.


Story Source:

The above story is based on materials provided by Case Western Reserve University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Yu Cheng, Joseph D. Meyers, Ann-Marie Broome, Malcolm E. Kenney, James P. Basilion, Clemens Burda. Deep Penetration of a PDT Drug into Tumors by Noncovalent Drug-Gold Nanoparticle Conjugates. Journal of the American Chemical Society, 2011; 110204112210047 DOI: 10.1021/ja108846h

Cite This Page:

Case Western Reserve University. "A loose grip provides better chemotherapy." ScienceDaily. ScienceDaily, 5 February 2011. <www.sciencedaily.com/releases/2011/02/110204205509.htm>.
Case Western Reserve University. (2011, February 5). A loose grip provides better chemotherapy. ScienceDaily. Retrieved April 25, 2014 from www.sciencedaily.com/releases/2011/02/110204205509.htm
Case Western Reserve University. "A loose grip provides better chemotherapy." ScienceDaily. www.sciencedaily.com/releases/2011/02/110204205509.htm (accessed April 25, 2014).

Share This



More Health & Medicine News

Friday, April 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Fungus Killing Bats, Spreading in US

Deadly Fungus Killing Bats, Spreading in US

AP (Apr. 24, 2014) A disease that has killed more than six million cave-dwelling bats in the United States is on the move and wildlife biologists are worried. White Nose Syndrome, discovered in New York in 2006, has now spread to 25 states. (April 24) Video provided by AP
Powered by NewsLook.com
Companies Ramp Up Wellness to Lower Health Costs

Companies Ramp Up Wellness to Lower Health Costs

AP (Apr. 24, 2014) That little voice telling you to exercise, get in shape and get healthy is probably coming from your boss. More companies are beefing up wellness programs to try and cut down their health care costs. (April 24) Video provided by AP
Powered by NewsLook.com
Blood From World's Oldest Woman Suggests Life Limit

Blood From World's Oldest Woman Suggests Life Limit

Newsy (Apr. 24, 2014) Scientists say for the extremely elderly, their stem cells might reach a state of exhaustion. This could limit one's life span. Video provided by Newsy
Powered by NewsLook.com
FDA Wants To Ban Sales Of E-Cigarettes To Minors

FDA Wants To Ban Sales Of E-Cigarettes To Minors

Newsy (Apr. 24, 2014) The Food and Drug Administration wants to crack down on the use of e-cigarettes, banning the sale of the product to minors. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins