The effectiveness of therapeutic gene delivery can be enhanced by coating DNA with a topical steroid, according to bioengineers at the University of Pennsylvania.

The researchers noted that dexamethasone, a common anti-inflammation steroid, when wrapped around a DNA strand can be effective to prevent the immune responses that are generally associated with gene-transfer techniques.

From Sciencedaily.com:

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 dexamethasone 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 inflammatory 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.”

The study techniques were conducted in animal models and were presented in the Feb. 15 issue of the journal Gene Therapy, available online.