DENVER — A novel acne laser treatment that uses infrared-activated gold nanoparticles to deliver thermal damage to sebaceous follicles is safe and effective for reducing inflammatory lesions, according to a new study.
"So far, nobody has successfully taken a physical approach to the selective destruction of the sebaceous glands," said Rox Anderson, MD, professor of dermatology at Harvard Medical School in Boston.
He presented the results here at the American Academy of Dermatology 72nd Annual Meeting.
There are many treatments for acne, but it often reappears after treatment has ended. Researchers have therefore become interested in inactivating the overactive sebaceous glands that can lead to pore blockage and inflammation.
With the laser treatment, gold nanoparticles are worked into the gland using an emulsion and a topical vibrating massage device. The particles are tuned to absorb near-infrared light, heat up, and cause thermal damage to the gland. The treatment uses 800 nm laser irradiation without anesthesia.
Dr. Anderson's team conducted 2 studies of the laser therapy.
In the first, they evaluated 48 subjects; 23 were treated with gold nanoparticles, and 25 used over-the-counter face wash (2% salicylic acid) for 12 weeks and then crossed over to gold nanoparticle treatment.
Gold nanoparticle therapy was administered in 3 sessions, each 2 weeks apart.
At week 12, the mean reduction in inflammatory lesions was significantly better in the nanoparticle group than in the face wash group (34% vs 16%; P = .02).
At week 16, the reduction in lesions was the same in the nanoparticle and the face wash/nanoparticle crossover groups (38% vs 38%).
At week 28, the mean reduction was larger in the nanoparticle group than in the crossover group (61% vs 50%).
Subjects reported mild to moderate pain during the laser procedure. Adverse effects included mild erythema, which went away 30 to 60 minutes after the procedure.
In the second study, the researcher team evaluated 49 subjects who received 3 treatments administered at 1-week intervals; 26 subjects received gold nanoparticle treatment and 23 received sham treatment.
At 16 weeks, the mean reduction in inflammatory lesions was significantly better in the nanoparticle group than in the sham group (53% vs 31%; P = .045).
Table. Acne Scores on the Investigator's Global Assessment Scale
| Outcome | Nanoparticle Group, % | Sham Group, % |
| Score of 0 | 24 | 0 |
| Improvement ≥2 points | 32 | 0 |
"The technology is now all the way through some human studies, and it looks like it's going to work," Dr. Anderson reported.
"I think it's a very interesting avenue, given that we've been looking to explore new methods to get beyond our current strategies of retinoids," said Carolyn Jack, MD, PhD, a resident in dermatology at McGill University in Montreal. "Phototherapy and light therapy have an immense value, and they are very popular. Patients really do like it," she told Medscape Medical News.
However, it is not clear how long the sebaceous glands will be inactivated after treatment, or how long it will take for acne to recur, she noted.
There is also concern about the safety of long-term exposure to gold nanoparticles, particularly because they are being used now in sunscreens. It is not clear "where these nanoparticles are going in the body, how they're absorbed systemically, and what the long-term effects may be," said Dr. Jack.
Dr. Anderson countered that with this therapy, the gold nanoparticles are much larger than those used in sunscreens. He also pointed out that tattoos are optically active nanoparticles.
"The fact that about 25% of the American adult population is walking around with optical nanoparticles in them fairly safely is a good precedent," he said.
Dr. Anderson is a consultant for Sebacia, which funded the study and is commercializing the technology. Dr. Jack has disclosed no relevant financial relationships.
American Academy of Dermatology (AAD) 72nd Annual Meeting. Presented March 22, 2014.
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Cite this: Gold Nanoparticle Treatment for Acne - Medscape - Mar 27, 2014.
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