Acne Treatment Based on Selective Photothermolysis of Sebaceous Follicles with Topically Delivered Light-Absorbing Gold Microparticles

Abstract

The pathophysiology of acne vulgaris depends on active sebaceous glands, implying that selective destruction of sebaceous glands could be an effective treatment. We hypothesized that light-absorbing microparticles could be delivered into sebaceous glands, enabling local injury by optical pulses. A suspension of topically applied gold-coated silica microparticles exhibiting plasmon resonance with strong absorption at 800 nm was delivered into human pre-auricular and swine sebaceous glands in vivo, using mechanical vibration. After exposure to 10–50 J cm−2, 30 milliseconds, 800 nm diode laser pulses, microscopy revealed preferential thermal injury to sebaceous follicles and glands, consistent with predictions from a computational model. Inflammation was mild; gold particles were not retained in swine skin 1 month after treatment, and uptake in other organs was negligible. Two independent prospective randomized controlled clinical trials were performed for treatment of moderate-to-severe facial acne, using unblinded and blinded assessments of disease severity. Each trial showed clinically and statistically significant improvement of inflammatory acne following three treatments given 1–2 weeks apart. In Trial 2, inflammatory lesions were significantly reduced at 12 weeks (P=0.015) and 16 weeks (P=0.04) compared with sham treatments. Optical microparticles enable selective photothermolysis of sebaceous glands. This appears to be a well-tolerated, effective treatment for acne vulgaris.

Transfollicular delivery of gold microparticles in healthy skin and acne vulgaris, assessed by in vivo reflectance confocal microscopy and optical coherence tomography

“…Further, the imaging technologies illustrated that skin areas with active acne elements and an intact surface did not influence delivery of GMPs and that delivery of GMPs was similar in acne patients and healthy participants. RCM illustrated laser‐mediated thermal effect around NSOs containing GMPs from skin surface to dermo‐epidermal junction, indicating that not only the deeper parts of the pilosebaceous units, but also the upper infundibular portion are affected by the heat generated after laser exposure of GMPs .…”

Two optical coherence tomography systems detect topical gold nanoshells in hair follicles, sweat ducts and measure epidermis

“…These particular 150 nm GNSs were selected because they have been demonstrated to penetrate into hair follicles easily after vibratory massage. The GNSs are certified as medical device CE 612960 and approved for clinical use and topical treatment of acne vulgaris combined with selective photothermolysis . in vivo studies have shown that these GNSs are not retained in swine skin 1 month after vibratory massage into the skin and that uptake in other organs is negligible since it is 74 times lower than the established safety threshold .…”

“…The GNSs are certified as medical device CE 612960 and approved for clinical use and topical treatment of acne vulgaris combined with selective photothermolysis . in vivo studies have shown that these GNSs are not retained in swine skin 1 month after vibratory massage into the skin and that uptake in other organs is negligible since it is 74 times lower than the established safety threshold . The GNS is supplied in glass vials in a 25% solution in quantities of 1 mL (Sebacia Microparticles, Sebacia Inc., Duluth, Georgia) suspended in a combination of ethanol (54%), polysorbate 80 (1%) and diisopropyl adipate (20%).…”

Optimizing Non-Antibiotic Treatments for Patients with Acne: A Review

“…IPL efficacy did not appear to be significantly enhanced when combined with PDT [62, 64–68]. IPL’s efficacy may be due in part to its longer wavelengths, which have the ability to produce selective photothermolysis of sebaceous glands; sebum has an absorption peak at 1210 nm [69]. LPDL, which uses a wavelength of 595 nm, was more effective at decreasing ILC in patients with mild to severe acne when combined with PDT (67% vs. 100%) [70, 71].…”