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 September 19, 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 September 19, 2014).

Share This



More Health & Medicine News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
How The 'Angelina Jolie Effect' Increased Cancer Screenings

How The 'Angelina Jolie Effect' Increased Cancer Screenings

Newsy (Sep. 19, 2014) Angelina's Jolie's decision to undergo a preventative mastectomy in 2013 inspired many women to seek early screenings for the disease. Video provided by Newsy
Powered by NewsLook.com
The Cost of Ebola

The Cost of Ebola

Reuters - Business Video Online (Sep. 18, 2014) As Sierra Leone prepares for a three-day "lockdown" in its latest bid to stem the spread of Ebola, Ciara Lee looks at the financial implications of fighting the largest ever outbreak of the disease. Video provided by Reuters
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