Gold Microparticles Zap Sebaceous Follicles

This article is sourced from Dermatology Times.

Selectively heating sebaceous follicles with topically-delivered, light-absorbing gold microparticles is a safe and effective treatment for acne, according to an article1 published in April 2015 in the Journal of Investigative Dermatology. If approved by the U.S. Food and Drug Administration (FDA), the device could offer an in-office treatment alternative to acne patients’ daily use of pills and creams.

“Acne is definitely known to be a disorder of the sebaceous hair follicle,” said R. Rox Anderson, M.D., professor of dermatology at Harvard Medical School, director of the lab at the Wellman Center for Photomedicine at Massachusetts General Hospital and the article's senior author, in the publication. “Yes, there’s a bacterium involved. And, yes, there are immunological responses, but we’ve always known acne depends on having active sebaceous glands.”

Sebacia Inc. is developing the combination treatment of a topical suspension of light-absorbing microparticles and a dermatology laser. Researchers are enrolling patients for a U.S. pivotal clinical trial to begin the device’s FDA approval process.

To a point, the concept is similar to laser hair removal. Heat from the laser destroys or disarms the follicle, said Anderson.

Gold Nano Shells

While brown or black hair has pigment attracting light in a hair follicle, there is no such target in sebaceous glands. Anderson and colleagues had to find something to put into the gland to allow the laser to heat and, potentially, destroy it. According to Anderson gold nano shells are the solution.

“[Gold nano shells] are made with a very thin layer of gold wrapped around a glass core,” he said, in the article. “The structure absorbs more light than just about any other material.”

The infrared wavelength used to heat the sebaceous gland is 800 nm—the same used in laser hair removal.

“That means the light source is already out there in medical use, all around the world,” explained Anderson, in the publication. "That’s an advantage, but it also means that some pigmented hair may also be removed during this treatment.”

Hair removal could be an issue dermatologists should consider for males with acne and a dark beard in the same area, added Anderson.

Two human studies conducted in Europe, of patients with moderate to severe facial acne, showed treatment helps clear patients’ skin.

Each trial showed clinically and statistically significant improvement of inflammatory acne following three treatments, given one to two weeks apart, according to the publication. The second trial showed inflammatory lesions were significantly reduced at 12 and 16 weeks, compared with control treatments. Results were seen as early as four weeks post-treatment.

Selective Photothermoloysis

Histology studies suggested the Sebacia treatment, a process called selective photothermolysis, selectively targeted sebaceous follicles and glands.

Treatment was well tolerated, with mild and transient redness and swelling after each procedure. By a month post-treatment, subjects had no gold particles remaining in their skin.

“My biggest worry [during the studies] was that we’d accidently tattoo people, which would be a show-stopper,” said Anderson, in the article. “Tattoos inks are also light-absorbing nanoparticles that lodge permanently in the skin. Fortunately, this gland is programmed by nature to extrude itself onto the surface. What happens is the particles go in, the light is used to heat up the gland and then the debris is kind of spit out.”

When asked how he thinks selective photothermolysis compares to available acne therapies, Anderson said the process by Sebacia appears to be as effective as today’s most popular antibiotic and topical treatments, but not as powerful as oral isotretinoin.

The device is not a drug, which is a major benefit to using it and if the next studies pan out, it will have long-lasting benefits for acne sufferers.

“What we’re after is something that’s closer to a cure; meaning, you do a handful of treatments and then you have a long-term remission of your acne,” added Anderson, in the publication.


1. Paithankar DY, Sakamoto FH, Farinelli WA, et al. Acne Treatment Based on Selective Photothermolysis of Sebaceous Follicles with Topically Delivered Light-Absorbing Gold Microparticles. J Invest Dermatol. 2015.

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