According to bioengineers at the University of Pennsylvania, coating DNA with a topical steroid can prove to be effective option for formulating effective therapeutic gene delivery. It was concluded by researchers that a popular anti-inflammatory steroid, when wrapped around a DNA strand, can prove effective in preventing immune responses that are commonly associated with gene-transfer techniques.
Scott Diamond, Senior Author and Professor of bioengineering at Pennsylvania and Associate Director of Penn’s Institute for Medicine and Engineering, remarked that steroid coating is not only beneficial in allowing genes to be taken up into a cell in an easy manner but also prevents the kind of anti-inflammatory response that is visible in gene transfer therapy.
From Eurekalert.org:
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.”
Diamond said that a steroid coating can prove effective in improving the chances of successful gene transfer in humans.
