Featured Research

from universities, journals, and other organizations

Steroid-coated DNA Represents New Approach To Gene Delivery

Date:
February 13, 2004
Source:
University Of Pennsylvania
Summary:
Coating DNA with a topical steroid might make for more effective therapeutic gene delivery, according to bioengineers at the University of Pennsylvania. The researchers have shown that a common anti-inflammatory steroid, wrapped around a strand of DNA, can prevent the immune responses commonly associated with gene-transfer techniques.

PHILADELPHIA – Coating DNA with a topical steroid might make for more effective therapeutic gene delivery, according to bioengineers at the University of Pennsylvania. The researchers have shown that a common anti-inflammatory steroid, wrapped around a strand of DNA, can prevent the immune responses commonly associated with gene-transfer techniques.

Studies of the technique, performed in animal models, are presented in the Feb. 15 issue of the journal Gene Therapy, available online now.

"The steroid coating not only allows the gene to be taken up into a cell more easily, but the steroid itself also prevents the sort of inflammatory immune response seen in gene transfer therapy," said Scott Diamond, senior author and professor of bioengineering at Penn and associate director of Penn's Institute for Medicine and Engineering. "The concept paves the way to coupling therapeutic gene delivery with a pharamacological agent, an approach that mitigates some of the drawbacks to the gene-delivery techniques in use now."

Currently there are two basic approaches to delivering therapeutic genes: nonviral and viral. Injecting a subject with pure DNA is possible, but a DNA molecule, by itself, has inherent trouble in entering cells. Viral carriers can serve as delivery vehicles for DNA, literally infecting cells with new genes. Both methods, however, are associated with the creation of inflammatory immune responses that reduces the action of the therapeutic gene.

DNA is a large and negatively charged molecule, which is the source of the stumbling point in getting cells to take up DNA. To counter the negative charge of DNA, Diamond and his colleagues took a common steroid, dexamethasone, and made it "sticky" by adding a nitrogen-rich, postively charged tail. This tail provides the glue that attaches the steroid to the naked DNA.

"The steroid is a fatty lipid so, in essense, we have greased up DNA for cellular uptake," Diamond said, "plus the cells get a big dose of steroid."

According to Diamond, the chemistry involved in manufacturing this new steroid vehicle is a fairly straightforward, one-step process that is simple compared to creating viral gene-therapy vectors. "But this is more than just 'gene therapy on steroids,'" Diamond said. "The dexmethasone not only eased inflammation in an animal model, but, as our study showed, actually allowed the cells to use the foreign DNA more effectively."

In addition, corticosteroids can suppress the major inflammatory cytokines created by the immune response after gene delivery. According to studies in cell culture and animal models, the steroid-coated DNA showed lower initial inflammation and greater expression of the gene over time. The results have encouraged the researchers to continue studies and to envision broader application of the technique toward diseases that might also benefit from gene-transfer therapy.

"In humans, especially in inflamatory diseases, a steroid coating would greatly enhance the chances of successful gene transfer" Diamond said. "As an alternative, I could foresee the use of this coating technique to tailor therapies by choosing drugs that would amplify the benefit of a particular therapeutic gene."


Story Source:

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


Cite This Page:

University Of Pennsylvania. "Steroid-coated DNA Represents New Approach To Gene Delivery." ScienceDaily. ScienceDaily, 13 February 2004. <www.sciencedaily.com/releases/2004/02/040212080959.htm>.
University Of Pennsylvania. (2004, February 13). Steroid-coated DNA Represents New Approach To Gene Delivery. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2004/02/040212080959.htm
University Of Pennsylvania. "Steroid-coated DNA Represents New Approach To Gene Delivery." ScienceDaily. www.sciencedaily.com/releases/2004/02/040212080959.htm (accessed August 22, 2014).

Share This




More Health & Medicine News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Cadavers, a Teen, and a Medical School Dream

Cadavers, a Teen, and a Medical School Dream

AP (Aug. 21, 2014) Contains graphic content. He's only 17. But Johntrell Bowles has wanted to be a doctor from a young age, despite the odds against him. He was recently the youngest participant in a cadaver program at the Indiana University NW medical school. (Aug. 21) Video provided by AP
Powered by NewsLook.com
American Ebola Patients Released: What Cured Them?

American Ebola Patients Released: What Cured Them?

Newsy (Aug. 21, 2014) It's unclear whether the American Ebola patients' recoveries can be attributed to an experimental drug or early detection and good medical care. Video provided by Newsy
Powered by NewsLook.com
Lost Brain Cells To Blame For Sleep Problems Among Seniors

Lost Brain Cells To Blame For Sleep Problems Among Seniors

Newsy (Aug. 21, 2014) According to a new study, elderly people might have trouble sleeping because of the loss of a certain group of neurons in the brain. 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