Skin cancer patients and others may soon benefit from a non-invasive form of gene therapy. A topical treatment uses nanotechnology to deliver gene-regulation technology exactly where it’s needed.
Topical gene therapy has been in use since the 1990s, but the advance made by a Northwestern University research team is to mate it with nanotechnology to overcome some of the difficulties in using it for skin cancer treatment. The skin, as the protector of the body, is highly resistant to letting substances through.
The team, led by dermatologist Amy S. Paller and chemist Chad Mirkin, uses specially constructed nucleic acids called small interfering RNA. The siRNA clusters around gold nanoparticles consisting of only a few atoms to form spheres about 1,000 times smaller than the diameter of a human hair. The RNA is highly programmable, meaning it is relatively easy to manufacture to target a specific gene.
In the study, siRNA was engineered to bind to natural proteins the skin does let through. When it gets inside it identifies cancer cells with epidermal growth factor receptor. The nanomedication then switches the cancer cells off, leaving healthy cells alone.
“This allows us to treat a skin problem precisely where it is manifesting—on the skin,” Dr. Paller said in a release. “We can target our therapy to the drivers of disease, at a level so minute that it can distinguish mutant genes from normal genes. Risks are minimized, and side effects have not been seen to date in our human skin and mouse models.”
In addition to the common skin cancers melanoma and squamous cell carcinoma, this technique is being looked at for use in fighting psoriasis, diabetic wound healing and the rare genetic disorder epidermolytic ichthyosis, a skin disease for which no treatment is known. Future research may look at using it for wrinkles and other signs of aging.
“Many of the ways we treat disease are based on old methods and materials. Nanotechnology offers the ability to very rapidly create new structures with properties that are very different from conventional forms of matter,” Mirkin said.
Mirkin developed the technology used more than 15 years ago. While it has widespread diagnostic applications, only recently was its ability to penetrate skin realized, along with the possibility of using that ability to improve delivery of treatments.