Exploring New Research at Stratum Corneum 2012

By: Katerina Steventon, PhD, FaceWorkshops

Posted: November 1, 2012

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In the Desquamation session, which was supported by DSM, Michel Simon, PhD, of University of Toulouse reported on properties and functions of filaggrin-related proteins (filaggrin-2 and hornerin) that are important for keratinocyte differentiation. Their decreased expression may contribute to barrier defects in atopic dermatitis (AD). Ulf Meyer-Hoffert, PhD, from the University of Kiel looked at inhibition of kallikrein-related peptidases, involved in inflammation and desquamation, to maintain the epidermal homeostasis. Mark Donovan, PhD, of L’Oréal Recherche outlined new perspectives on desquamation, studying the degradation of the corneo-desmosomal proteins through a combination of proteomics and atomic force microscopy in normal and aged skin.

A comprehensive review of SC antimicrobial peptides by Jens Schroder, PhD, of the University of Kiel, discussed the SC being covered with microorganisms that do not infect the skin. The antimicrobial barrier preferentially kills or inhibits potentially pathogenic bacteria from the gastrointestinal system. Three distinct peptide barrier systems, at specific locations within the SC, constitute the innate defense system of healthy skin.

Transdermal Absorption Through SC

The Skin Forum session was introduced by Professor Jonathan Hadgraft, PhD, of the University of London, sharing the work of the late Professor Johann Wiechers, PhD. The skin, as an effective barrier, presents a challenge for the formulator of topical and transdermal products. The solubility of the active compound is important. It has to pass sequentially through hydrophilic and lipophilic domains of structured lipid bilayers that can be modified by excipients when “formulating for efficacy.” The session further explored issues of transdermal absorption in vitro and micro-needle delivery.

Penetration of lipophilic and hydrophilic actives into skin was also discussed by Franziska Fleischli, PhD, of the Zurich University of Applied Sciences. Cosmetic and pharmaceutical products are applied for different purposes, and the depth of the penetration depends on the active compound as well as the formulation. She compared the penetration into skin models in vitro and human skin in vivo, confirming different penetration profiles.

Barrier Function in Adult and Baby SC

Neelam Muizziddin, PhD, of Esteé Lauder Companies looked at the adaptation of skin to climates and seasons. Basal transepidermal water loss (TEWL) is reduced in a dry versus humid environment; skin chronically exposed to hot, dry climate exhibits a stronger barrier. Skin barrier is weaker in winter than in summer.