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.

Related Articles


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 March 1, 2015 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 March 1, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, March 1, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Rehab Robot Helps Restore Damaged Muscles and Nerves

Rehab Robot Helps Restore Damaged Muscles and Nerves

Reuters - Innovations Video Online (Mar. 1, 2015) A rehabilitation robot prototype to help restore deteriorated nerves and muscles using electromyography and computer games. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Could a $34 Smartphone Device Improve HIV Diagnosis in Africa?

Could a $34 Smartphone Device Improve HIV Diagnosis in Africa?

Reuters - Innovations Video Online (Feb. 27, 2015) A dongle that plugs into a Smartphone mimics a lab-based blood test for HIV and syphilis and can detect the diseases in 15 minutes, say researchers. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Doctor Says Head Transplants Possible Within Two Years

Doctor Says Head Transplants Possible Within Two Years

Buzz60 (Feb. 27, 2015) An Italian doctor is saying he could stick someone&apos;s head onto someone else&apos;s body. Patrick Jones (@Patrick_E_Jones) reports. Video provided by Buzz60
Powered by NewsLook.com
How Your Dentist Could Help Screen You For Diabetes

How Your Dentist Could Help Screen You For Diabetes

Newsy (Feb. 27, 2015) A new study from researchers at New York University suggests dentists could soon use blood samples taken from patients&apos; mouths to test for diabetes. 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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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