ENPNewswire-July 26, 2019--Kao - Effect of the stratum corneum barrier function on cutaneous photosensitivity
Release date- 26072019 - As part of its ongoing research of healthy and beautiful skin, the Kao Corporation (President: Michitaka Sawada) Biological Science Laboratories and Skin Care Products Research Laboratories found that skin with a reduced cutaneous (stratum corneum) barrier function is prone to UVB-induced irritation.
ABSTRACT Important differences exist in the physiology of the stratum corneum
barrier according to demographic, cultural, and medical factors.
The main barrier of the skin is located in the outermost layer of the skin, the stratum corneum
. The stratum corneum
consists of corneocytes surrounded by lipid regions.
Among all the body parts, the footpad had the thickest stratum corneum
(31+-2 um; Mean +- SD) and epithelial layer (35+-7 um).
We employed optical scanning laser confocal microscopy and size-selected fluorospheres to demonstrate that 0.5- and 1.0-[micro]m particles, in conjunction with motion, as at the wrist, penetrate the stratum corneum
of human skin and reach the epidermis and, occasionally, the dermis.
While doing research at the University of Toronto, we hypothesized that cerumen impaction is not a result of overproduction in the ceruminous glands, but a failure of individual corneocytes in the stratum corneum
Each needle in the 3mm square patch is less than 0.02 cm (0.006 in) long, and penetrates only the outermost layer of skin, the stratum corneum
. The stratum corneum
contains no nerve endings--thus, there's no sensation of pain.
The barrier faced by investigators pursuing the idea has been the stratum corneum
, a dense layer of dead cells that forms the outermost layer of skin.
A sunscreen containing 5% ZnO and 12.17% Ti[O.sub.2] was spread over a 3-cm by 3-cm site on the forearm and allowed to remain in contact with the skin for 30 minutes with residual product then being removed, and a confocal laser scanning microscope (CLSM) was used to capture images of the stratum corneum
The interaction of a potent percutaneous penetration enhancer, 1,8-cineole, with the stratum corneum
(SC) and DPPC membranes was investigated by electron paramagnetic resonance spectroscopy (EPR) of spin-labeled analogs of stearic acid (5DSA) and androstanol (ASL).
In healthy skin, the stratum corneum
is a resilient, protective skin lipid barrier against environmental challenges and moisture loss.