Experimental laser targets sebaceous glands to treat acne

Kissimmee, Fla. - A laser approach that selectively targets the sebaceous glands may prove to be an effective future therapy for acne, said Fernanda H. Sakamoto, M.D., Ph.D., at the 2012 annual meeting of the American Society for Laser Medicine and Surgery.

“The success of permanent laser hair removal suggests that selective photothermolysis of the sebaceous glands could be a bona fide target in terms of an effective approach in treating acne. Currently, we are studying different wavelengths and working on developing a laser that can selectively target and destroy the sebaceous glands,” says Dr. Sakamoto, Wellman Center for Photomedicine, department of dermatology, Massachusetts General Hospital, Boston.

To determine the wavelengths that could potentially target the sebaceous glands, Dr. Sakamoto studied the absorption spectra of natural and artificially prepared sebum ranging from 200 nm to 3,000 nm. In preliminary in vitro experiments, Dr. Sakamoto used the Jefferson National Accelerator superconducting free electron laser (FEL) to measure photothermal excitation of aqueous gels and artificial sebum, and the sebaceous sites of pigskin, human scalp and forehead skin.

The in vitro skin samples were exposed to FEL pulses ranging from 1,620 nm to 1,720 nm, spot diameter 7 mm to 9.5 mm, with exposure through a cold 4 degrees Celsius sapphire window in contact with the skin.

Study results
Results of the study showed that both the artificial and natural sebum had absorption peaks near 1,210 nm, 1,728 nm, 1,760 nm, 2,306 nm and 2,346 nm. The laser-induced heating of the artificial sebum was found to be approximately twice that of water at 1,710 nm and 1,720 nm, and approximately one and a half times higher in human sebaceous glands compared to water.

“Based on the results from our preliminary study, selective photothermolysis targeting the sebaceous glands looks promising, and though more research needs to be done, an effective laser treatment for acne does look feasible,” Dr. Sakamoto says.

In the study, those skin samples exposed approximately to 1,700 nm with around 100 to 125 millisecond pulses demonstrated selective thermal damage to the sebaceous glands, Dr. Sakamoto says. In addition, none of the samples showed any epidermal trauma, underscoring the selectivity of the wavelength and the potential safety of the treatment approach.

In continued research, Dr. Sakamoto is studying three prototype diode lasers with three different wavelengths: 1,700 nm, 1,720 nm and 1,726 nm. Of these, the 1,726 nm wavelength appears to be the more effective option for targeting the sebaceous glands, she says.

According to Dr. Sakamoto, the prototype laser can particularly target the sebaceous glands, whereas other currently available lasers used for acne treatment target water and vessels.

“The sebaceous glands are primarily composed of lipids and water. We hope that this new laser will be more efficient as well as more selective for those targets, offering us a new and more efficient treatment of acne,” Dr. Sakamoto says.

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