A cream currently used to treat skin cancers and warts could hold the answer to stopping scar formation after injuries or surgery, suggests early-stage research from the University of Pennsylvania.
Most wounds heal with some kind of scar and bad scarring can cause both physical and mental health problems in those affected. Despite this widespread problem, there are few medical solutions available that can treat it.
Thomas Leung, a physician and researcher based at the University of Pennsylvania, and his team are looking into ways to heal wounds without scars.
“In the natural world, salamanders have been hailed as champions of regeneration, exhibiting a remarkable ability to regrow tissues, organs, and even whole body parts,” says Leung.
“Some of this ability has been retained in humans, as human livers can regenerate, and traumatic fingertip amputations in children also heal without scar formation. These examples suggest that the mechanisms driving scarless wound healing, though rarely active, still exist in humans, and we need to figure out ways to re-engage these pathways.”
A scar is an area of fibrous tissue that replaces normal skin after an injury.
The research is still at an early stage, but Leung and colleagues have shown that use of the cream imiquimod, a treatment for some skin cancers and warts, can stop scar formation in mice.
Imiquimod has been used in the clinic since 1997 and so although it has not been used to treat scars, a lot is already known about its safety in humans. While it can cause inflammation, it is generally considered to be safe for most people to use.
“Repurposing existing drugs for new indications is cheaper and faster than starting from scratch. We hope this will speed up translation into the clinic,” notes Leung.
When the team looked into how the cream stops scarring in more detail, they found that it activated neurological cells in the skin that control sensations like pain, cold or itchiness.
Interestingly, the scientists found that it did not matter where on the mouse's skin they applied the cream. It had the healing effect regardless of whether it was applied directly on the wound or not, suggesting that imiquimod triggered a regenerative process across the whole body and not just in the local area it was applied in.
“This suggests that imiquimod stimulates a ‘factor’ that circulates throughout the body to promote scarless wound healing,” says Leung.
“We plan to run a clinical trial to see if topical imiquimod cream can reduce scar formation in patients receiving elective surgery. Since local imiquimod can promote healing on distant wounded sites, we plan to have patients apply the cream on a part of their body that is not receiving surgery,” says Leung.
The team also plans to look into how the neurological cells imiquimod activates communicate with the immune system to stop scars being formed.
The research discussed in this article is published in the journal Science Immunology and was funded by the National Institute of Health, Department of Veteran’s Affairs, Moseley Foundation, and the HT Leung foundation.
