From the Journals

Hair regrowth stimulated by microneedle patch in preclinical study


Those who are unhappy about losing their hair might be interested to hear about a new approach where scientists use mechanical stimulation to promote hair regrowth.

Currently, Food and Drug Administration–approved drugs for hair loss include minoxidil (Rogaine) and finasteride (Propecia). But there are side effects, and the treatments only work when continuously used for an extended time.

Some people may opt instead to have hair follicle transplants, but study coauthor Fangyuan Li, PhD, from the College of Pharmaceutical Sciences at Zhejiang University in Hangzhou, China, explains, the surgery is painful and not always successful because it depends a lot on the quality of donor hair follicles, which can vary.

Seeking to develop a new nonsurgical option, the scientists, led by Jianqing Gao, vice dean of the College of Pharmaceutical Sciences at Zhejiang University, designed a dissolvable microneedle patch to deliver treatment near hair roots beneath the skin.

Male- or female-pattern baldness can be permanent when there aren’t enough blood vessels surrounding hair follicles to deliver nutrients and other essential molecules. A buildup of reactive oxygen in the scalp can prompt the death of cells that would otherwise grow new hair.

In a previous investigation, the researchers found that nanoparticles containing cerium, a silvery-white metal, can mimic the enzymes inside the body that can help ease oxidative stress.

The scientists coated cerium nanoparticles with a biodegradable compound. Then they made the microneedle patch by pouring a mixture of hyaluronic acid with cerium-containing nanoparticles into a mold.

The small needles don’t hurt when applied, Dr. Li said, as they deliver treatment to a region under the skin with no pain receptors.

The researchers tested control patches and the cerium-containing ones on male mice with bald spots created by a hair-removal cream. Both applications stimulated new blood vessels to form around the mice hair follicles. But those treated with the nanoparticle patch showed faster signs of hair recuperation at the root.

The mice also had fewer oxidative stress compounds in their skin. Microneedle patch use resulted in faster hair regrowth, compared with a cream-based treatment, and could be applied less frequently.

And though the idea is not yet ready to be tried on people, it represents an inventive step forward in addressing a common problem.

A version of this article first appeared on

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