Combining spherical (as opposed to linear) RNA with a common commercial moisturizer, Northwestern University researchers developed the first topical gene regulation therapy to accelerate the healing of ulcers associated with diabetes, at least in animals.
The team says that more than one-fifth of the 27 million Type 2 diabetics in the U.S. have chronic, non-healing skin wounds, leading to amputation in some cases.
"Finding a new way to effectively heal these resistant diabetic wounds is very exciting," said the director of Northwestern's Skin Disease Research Center, Dr. Amy S. Paller, in a statement. "But, in addition, this study further proved that SNAs--in nothing but common moisturizer--can penetrate the skin barrier, a challenge that other therapies have been unable to conquer."
The moisturizer used was Aquaphor. When an SNA silencing the gene that produces the enzyme GM3 synthase was put in Aquaphor and topically administered around the wounds of diabetic mice, healing time was improved by 50%. It took the experimental mice 12 days to heal, compared to 18 days for the control mice.
"This work illustrates the scope and potential impact of the SNA platform for treating conditions of the skin with a known genetic basis," said Northwestern chemist Chad A. Mirkin, who invented SNAs at Northwestern in 1996, in a statement. "It is the only known nucleic acid platform for treating such ailments and constitutes a new pipeline of therapeutics to address a broad swath of debilitating health conditions."
Besides the drug delivery potential of skin moisturizers, the other drug delivery nugget here is that the conformation of agents can matter a great deal, especially when it comes to RNA. When the team tried putting linear RNA into the Aquaphor, GM3 Synthase levels were not reduced and the therapy was ineffective.
"The spherical configuration really makes a difference," Mirkin said in a statement. "It is a very interesting observation with significant medical ramifications. By using nanotechnology and chemistry to restructure perhaps the most important molecule ever discovered by scientists, we go from a structure that cannot cross the natural barriers within the skin to one that freely traverses them."
Next up, the researchers are aiming to develop an SNA ointment to prevent diabetic ulcers rather than just treat them. "We think it also might be possible to prevent these ulcers, not just heal them, by rubbing the ointment on the bottom of the foot," Paller said. "Our team is looking at this now."
- more from Northwestern