Evaluating the Irritant Factors of Silicone and Hydrocolloid Skin Contact Adhesives Using Trans-Epidermal Water Loss, Protein Stripping, Erythema, and Ease of Removal.

A composite silicone skin adhesive material was designed to improve its water vapor permeability to offer advantages to wearer comfort compared to existing skin adhesive dressings available (including perforated silicone and hydrocolloid products). The chemical and mechanical properties of this novel dressing were analyzed to show that it has a high creep compliance, offering anisotropic elasticity that is likely to place less stress on the skin. A participant study was carried out in which 31 participants wore a novel silicone skin adhesive (Sil2) and a hydrocolloid competitor and were monitored for physiological response to the dressings. Trans-epidermal water loss (TEWL) was measured pre- and postwear to determine impairment of skin barrier function. Sil2 exhibited a higher vapor permeability than the hydrocolloid dressings during wear. Peel strength measurements and dye counter staining of the removed dressings showed that the hydrocolloid had a higher adhesion to the participants' skin, resulting in a greater removal of proteins from the stratum corneum and a higher pain rating from participants on removal. Once the dressings were removed, TEWL of the participants skin beneath the Sil2 was close to normal in comparison to the hydrocolloid dressings that showed an increase in skin TEWL, indicating that the skin had been highly occluded. Analysis of the skin immediately after removal showed a higher incidence of erythema following application of hydrocolloid dressings (>60%) compared to Sil2, (<30%). In summary, this modified silicone formulation demonstrates superior skin protection properties compared to hydrocolloid dressings and is more suitable for use as a skin adhesive.

Thirty Years (and More) of Hair Research Societies.

The contributions of the core hair research societies and their members over the past 30 years have advanced the field of hair research and the understanding and treatment of hair disorders and normal hair growth.

Topical odorant application of the specific olfactory receptor OR2AT4 agonist, Sandalore® , improves telogen effluvium-associated parameters.

BACKGROUND: Human hair follicles (HFs) express the olfactory receptor (OR)2AT4, which is selectively stimulated by the synthetic sandalwood-like odorant, Sandalore® . In organ-cultured, human scalp HFs, Sandalore® prolongs anagen and suppresses apoptosis by up-regulating intrafollicular IGF-1 mediated signaling. AIMS: The objective of this study is to demonstrate whether effects of Sandalore® observed ex vivo translate into a clinically relevant effect in patients with telogen effluvium. PATIENTS/METHODS: In a randomized, double-blinded, placebo-controlled, clinical trial, 60 female volunteers (18-65 years) affected by telogen effluvium received over a period of 24 weeks treatment with either 1% Sandalore® solution (n = 30) or placebo (identically smelling, but non-OR2AT4 activating sandalwood oil n = 30). The study read-out parameters were the degree of hair shedding, hair volume, terminal/vellus hair ratio, anagen/catagen-telogen ratio, and patient self-assessment. RESULTS: Sandalore® 1% ameliorated clinical signs of telogen effluvium, namely it reduced hair shedding, and increased hair volume and the percentage of anagen HFs, the latter two parameters significantly more than placebo when changes were calculated to baseline. Sandalore® also increased the ratio of terminal/vellus hairs at week 8. Most of the anti-hair shedding effects were seen after 8 weeks and maintained at week 24. Patient questionnaire showed that verum group patients were more satisfied than the placebo group in regard to the overall results. CONCLUSION: This clinical trial supports previous findings of anagen-prolonging effects of Sandalore® ex vivo with similar results now reproduced in clinical practice. It also provides proof-of-principle that a topically applied cosmetic odorant acting through HF olfactory receptors can be a therapeutic alternative to treat hair loss disorders characterized by excessive hair shedding such as telogen effluvium.

Bridging the "Dead Hair"-"Live Follicle" Divide in Applied Hair Research.

For many decades, applied hair research has been hampered by an unproductive intellectual and conceptual divide between researchers who are primarily interested in the hair shaft (HS), its structural properties, visual appearance and cosmetic manipulation, and those investigators who are mainly interested in the fascinating miniorgan that cyclically regenerates the HS, the hair follicle (HF). This article attempts to bridge this unproductive divide between the "dead hair" and "live follicle" worlds by summarizing both current key concepts and major open questions on how the HF, namely, the anagen hair bulb and its precortical hair matrix keratinocytes, generate the HS, focusing on selected key signaling pathways. We discuss current theories of hair shape formation and avenues toward impacting on human HS structure. The article closes by delineating which instructive preclinical research assays are needed to ultimately close the experimental gap between HS and HF researchers in a manner that benefits consumers.