Superhealing Drug Travels in Nanoparticles to Wounds
A new topical medicine suspended in nanoparticles could dramatically quicken the time it takes wounds to heal, researchers say.
The medicine could be used to speed the healing of all sorts of wounds, according to the researchers who are developing it. Applications could include everyday cuts and burns, surgical incisions, and chronic skin ulcers, which are a particular concern for the elderly and people with diabetes.
The medicine was tested on mice, which have a wound-healing process very similar to that of humans, according to study co-leader David Sharp, a professor of physiology and biophysics at Albert Einstein College of Medicine in New York. Sharp said he hopes to test the therapy on humans soon.
The work appears online this month in the Journal of Investigative Dermatology.
Wound healing is a complex process that involves moving a diverse group of cells and molecules to the source of injury. Even a small skin wound can take weeks to completely heal, from initial blood clotting and scabbing to tissue regeneration and scar formation.
"The faster and more directionally cells move into the wound, the faster the wound closes and the better it heals," Sharp said. [The 7 Biggest Mysteries of the Human Body]
Sharp and his colleagues had previously discovered that an enzyme called fidgetin-like 2 (FL2) interferes with healing by slowing the migration of various cells to the wound. FL2 acts to sever structures called microtubules, which are microscopic tubes within cells that provide cell structure and also a platform for transport among cells. FL2 may help to prevent abnormal tissue growth, but its complete function is not well known.
The researchers said they figured that temporarily inhibiting FL2 would enhance wound healing, so they crafted a drug to suppress the enzyme. This drug uses molecules of "silencing RNA," to turn off the gene that makes FL2.
In a test of cells growing in a lab dish, this drug resulted in skin cells migrating more than twice as fast as normal. However, if applied directly to a wound, the drug would rapidly degrade in the extra-cellular environment before it had a chance to block FL2.
This prompted the researchers to protect the drug, placing it in a nanoparticle gel to ferry it deep into the cells that needed it. The nanoparticles are about 50 times smaller than a human or mouse cell.
When applied to mice with cuts and burns, the nanoparticle therapy reduced the healing time by half, the researchers found. Sharp said that in a few months he hopes to test the therapy on pigs, whose skin resembles humans' even more closely.
If all continues to go well, FDA approval for human use might be possible within a few years, Sharp told Live Science. The approval time for topical medications is usually shorter than it is for oral medications, he said.
Nevertheless, the new drug may have potential for internal healing in addition to its use as a topical treatment.
"We're finding that skin is just the tip of the iceberg," Sharp said. "We've carried out pilot studies showing that FL2 can be targeted to promote regeneration of heart tissue after myocardial infarction and neural regeneration with recovery of function after peripheral nerve or spinal cord injury. These findings underscore the potent therapeutic potential of specifically regulating fundamental components of the cell's machinery to protect cellular viability and promote healing."
A group of researchers in India has developed a similar nanoparticle therapy that delivers silver nitrate, an antimicrobial agent, to burns without the typical side effects of silver nitrate, such as skin discoloration and damage to surrounding cells. This reduces the risk of infections and thus quickens healing.
Follow Christopher Wanjek @wanjek for daily tweets on health and science with a humorous edge. Wanjek is the author of "Food at Work" and "Bad Medicine." His column, Bad Medicine, appears regularly on Live Science.
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Christopher Wanjek is a Live Science contributor and a health and science writer. He is the author of three science books: Spacefarers (2020), Food at Work (2005) and Bad Medicine (2003). His "Food at Work" book and project, concerning workers' health, safety and productivity, was commissioned by the U.N.'s International Labor Organization. For Live Science, Christopher covers public health, nutrition and biology, and he has written extensively for The Washington Post and Sky & Telescope among others, as well as for the NASA Goddard Space Flight Center, where he was a senior writer. Christopher holds a Master of Health degree from Harvard School of Public Health and a degree in journalism from Temple University.
By Sascha Pare