BACKGROUND/AIMS Occlusion by covering the skin with an impermeable wrap enhances skin hydration, affects drug absorption and can induce the formation of a drug reservoir within the stratum corneum. This is desired in local therapy with topical corticosteroids. The aim of the study was to investigate the effect of occlusion before (experiment 1) and after (experiment 2) application on the penetr...

The diffusion equation has been solved numerically for the non steady-state problem of a two-dimensional, biphasic stratum corneum membrane. A brickand-mortar geometry was used, having variable relative phase permeability, corneocyte arrangement and corneocyte/lipid phase partition coefficient. The dependence of the diffusional pathway and the overall barrier function is shown to depend on thes...

The functional organization of the bovine rumen epithelium has been examined by electron and light microscopy combined with immunocytochemistry to define a transport model for this epithelium. Expression of connexin 43, an integral component of gap junctions, the tight-junction molecules claudin-1 and zonula occludens 1 (ZO-1), and the catalytic alpha-subunit of Na(+)-K(+)-ATPase was demonstrat...

In recent years, adhesive wound dressings have been increasingly applied postoperatively because of their ease of use as they can be kept in place without having to cut and apply surgical tapes and they can cover a wound securely. However, if a wound dressing strongly adheres to the wound, a large amount of stratum corneum is removed from the newly formed epithelium or healthy periwound skin. V...

The stratum corneum is a complex biological material characterized by very low permeability to water and most other molecules. This material may be thought of as a 'porous medium' composed of impermeable and permeable regions. Intercellular lipid membranes in the stratum corneum are postulated to exist in a mixture of two phases: solid (i.e. impermeable) and liquid crystalline (permeable). The ...

To maintain a constant thickness of the stratum corneum the desquamation rate and the de novo production of corneocytes is delicately balanced. Using a plantar stratum corneum model we have obtained evidence that proteolysis is a central event in the desquamation process. A number of regulatory mechanisms for desquamation have been postulated based on our findings.

Some of the views presented in the chapter on 'Examination of stratum corneum hydration state by electrical methods' in Skin Bioengineering - Techniques and Applications in Dermatology and Cosmetology (Karger, 1998) are in strong disagreement with the results from basic research that has been conducted on skin impedance measurement over the last decades. This research has e.g. non-ambiguously s...

Scanning confocal fluorescence microscopy was used to image localized regions of calcein transport across human stratum corneum during constant low-voltage (iontophoresis) and pulsed high-voltage exposures. Following an electrical protocol, imaging revealed regions of fluorescence which were interpreted as sites where transport of a fluorescent probe (calcein) into the stratum corneum had taken...

The data in this article shows the effect of isopropyl myristate (IPM) on a 2D Stratum Corneum lipid model. In the first part, the analytical characterization of the synthesized deuterated isopropyl myristate is given. Then a BAM image of the pure Stratum Corneum model used is shown and a dataset of surface-pressure - area isotherms considering various ratios of deuterated and non-deuterated IP...

Workers, both in the military and the commercial airline industry, are exposed to jet fuel by inhalation and dermal contact. We present a dermatotoxicokinetic (DTK) model that quantifies the absorption, distribution, and elimination of aromatic and aliphatic components of jet fuel following dermal exposures in humans. Kinetic data were obtained from 10 healthy volunteers following a single dose...