July 3, 2012 -- Imagine a lotion that can treat irreversible genetic skin diseases like psoriasis or life-threatening skin cancers like melanoma. Researchers at Northwestern University say they're another step closer to creating a treatment that will naturally slip through the skin and genetically alter cells to treat a particular skin disease.
Using creams and lotions to target a particular problem area is seen as a great advantage among many dermatologists in treating a localized skin problem.
"We like to treat skin diseases with topical creams so that we avoid side effects from treatments taken by mouth or injected," said Dr. Amy Paller, chair of dermatology and professor of pediatrics at Northwestern University Feinberg School of Medicine.
But the difficulty among researchers has been creating a gene-altering topical agent that can successfully penetrate the skin to specifically treat genetic skin diseases.
"The problem is that our skin is a formidable barrier," Paller said. "Genetic material can't get through the skin through regular means."
Using nanotechnology, the researchers packaged gene-altering structures on top of tiny particles of gold designed to target epidermal growth factor receptor, a genetic marker associated with many types of skin cancers. The structure is designed to sneak through the skin and latch onto targets underneath without eliciting an immune response.
The researchers mixed the structure into the ointment Aquaphor, which is commonly used among many patients who have dry skin or irritation.
The researchers then rubbed the ointment onto the mice and onto human skin tissue and saw the gene-altering structure in the lotion successfully penetrated the skin and was able to shut down the potentially cancer-causing protein, according to the findings published Monday in the journal Proceedings of the National Academy of Sciences.
The preliminary study is regarded as the first to deliver topical gene therapy effectively with no toxic effects.
Topical steroids are the most commonly used cream-based treatment for skin problems such as psoriasis. While they can treat inflammation or other effects of a skin disease, they do not treat the underlying mechanism that's causing the problem, Paller said. And in cases like melanoma, the diseased cells are often surgically removed from the skin, leaving scarring.
These new findings suggest that lotions may no longer be skin deep.
But even with no documented side effects found in the study, nanotechnology treatments, especially those that rely on gold particles, can potentially cause problems in the body in the long term, according to Dr. Mark Abdelmalek, chief of the division of laser and dermatologic surgery at Drexel University School of Medicine.
"It's naive to expect that putting something like this in the body would have absolutely no side effects," he said.
Another unknown is whether the approach will work on humans, and what the long term effects may be, he said.
"It is temporarily changing the protein while the structure is in contact with the cells, but it doesn't permanently change the genetic defect," Abdelmalek said. "This is all brand new and exciting, but there's still many things we just don't know."
The research is still in its earliest stages and not likely to be available for use soon. But researchers say the sequence of the structure can potentially be altered to match target genes for other skin-related conditions like melanoma, psoriasis, and even heal flesh wounds and scars. Research is under way to study these types of cases.
"These findings can dramatically change the way we treat diseases in the skin," said Chad Mirkin, director for the National Institute for Nanotechnology at Northwestern University. "This is a platform in principle that can be developed in diseases anywhere."
While the study specifically looked at the structure mixed with Aquaphor, the researchers said that it may be able to mix genetically altering particles with a variety of lotions, which could offer a wider variety of treatment options.
"It's an exciting new approach that has offered limitless opportunity to treat genetic skin diseases," Paller said.