Asuka Imai

Background: Dry skin is a universal skin concern that is often accompanied by itching, but moisturizers have not completely solved this issue. We found that the combination of a moisturizer (lotion) and an ultra‐thin film of fine fiber (FF) that we developed improved dry skin early, but the biological mechanism within the skin remained unclear.Materials and Methods: Eight (Study 1) and seven (Study 2) subjects used a lotion with and without the FF film on their lower legs. In addition to measurement of visual skin dryness scores and conductance, proteomic analysis of stratum corneum (SC) samples at baseline and 14 days after treatment in Study 1 and immunohistochemical staining of skin biopsy samples 3 or 5 days after treatment in Study 2 were performed.Results: Skin dryness scores and conductance improved more when the lotion was used with the FF film than with the lotion alone. The protein expression level of suprabasin, which is related to epidermal differentiation and barrier function, increased within a few days near the granular layer, as well as in the SC after 14 days. Proteomic analysis using SC samples showed that the FF film treatment with lotion decreased annexin A2, a dry skin marker, whereas it increased retroviral‐like aspartic protease 1, which is related to skin water content, more than lotion alone.Conclusion: The present findings suggest that lotion with the FF film initiates restoration of epidermal homeostasis, leading to early improvement of dry skin.

Background: Dry skin can trigger eczema that affects >10% of the US population. Dressing films have been developed to improve diseased skin, but there is limited knowledge about their effects, especially for dry skin‐related symptoms. We developed an electrospinning method that creates a coating film, called a fine fiber (FF) film, characterized by the production of a transparent, thin, flexible, and adherent membrane on the skin surface.Objective: The aim of this pilot study was to examine the effects of the FF film on dry skin.Methods: Three treatments (lotion only, lotion with the FF film, and lotion with an alternative film) were designed to treat subjects with rough skin on their lower legs. Twenty‐four females were enrolled and used either a water‐based lotion U or a petrolatum‐based lotion P and the FF film for 2 weeks followed by a regression phase for 1 week. Skin hydration and roughness scores were assessed as were the subjects’ perceptions of the effects.Results: When the FF film was applied with lotion U, skin hydration was significantly improved even after 1 week, accompanied by a significant improvement of skin roughness and an increase in skin hydration by the end of the regression phase. An evaluation of moisture permeability suggested that the FF film, especially with lotion U, performed as a semipermeable membrane with optimal moisture healing effects on dry skin.Conclusion: The FF film together with a water‐based lotion is a promising treatment to quickly improve dry skin conditions.

Autophagy is a membrane traffic system that provides sustainable degradation of cellular components for homeostasis, and is thus considered to promote health and longevity, though its activity declines with aging. The present findings show deterioration of autophagy in association with premature skin aging. Autophagy flux was successfully determined in skin tissues, which demonstrated significantly decreased autophagy in hyperpigmented skin such as that seen in senile lentigo. Furthermore, an exacerbated decline in autophagy was confirmed in xerotic hyperpigmentation areas, accompanied by severe dehydration and a barrier defect, which showed correlations with skin physiological conditions. The enhancement of autophagy in skin ex vivo ameliorated skin integrity, including pigmentation and epidermal differentiation. The present results indicate that the restoration of autophagy can contribute to improving premature skin aging by various intrinsic and extrinsic factors via the normalization of protein homeostasis.