Photothermal therapy using gold nanoparticles and a long-pulsed 755-nm alexandrite laser to treat facial photoaging in Asian skin: A prospective clinical trial

Background and Objectives: Transdermally delivered gold nanoparticles (AuNPs) irradiated with near-infrared laser energy can create a photothermal effect within the sebaceous glands (SGs). Photothermal therapy (PTT) can be used clinically to reverse photoaging in SG-rich areas of the skin. Improvements in wrinkles and enlarged pores in Asian skin were assessed following AuNP-mediated PTT with a long-pulsed 755-nm alexandrite laser. Study Design/Materials and Methods: A single-arm, prospective trial was designed. Twenty Korean patients underwent three gold PTT interventions performed 4 weeks apart at laser hair-removal settings without cooling. At Week 20, changes in the wrinkle index (WI) and pore index (PI), size, and count were calculated using three-dimensional camera analyses. Overall improvements in wrinkles and pores (0–4 scale) were assessed by blinded investigators using standardized photographic comparisons. The subjects scored their satisfaction (0–10 scale) and treatment discomfort (0–10 scale). Safety data were also collected. Results: There were significant reductions in the WI (8.3%, p < 0.01), pore size (23.1%, p = 0.035), and PI (19.9%, p = 0.034) in the periorbital areas at week 20 compared with baseline. The mean reductions in the size (22.5%, p = 0.027), count (16.5%, p = 0.048), and index (22.4%, p = 0.023) of the cheek pores were also significant. Investigators reported average scores of 3.2 ± 0.6 for improved wrinkle appearance, and 3.1 ± 0.7 for improvement in visible pores. Participants were moderately satisfied with the overall results (7.6 ± 1.8). Subjects felt moderate discomfort during treatment (4.7 ± 2.6). No serious or persistent adverse events occurred. Conclusions: AuNP-mediated PTT showed noticeable efficacy and tolerability in treating wrinkles and pores in Asian skin over a 12 week-follow-up. Further studies with a longer follow-up are needed to confirm the reduction in SG activity at the parameters used.