Reconstruction of functional human epidermis equivalent containing 5%IPS-derived keratinocytes treated with mitochondrial stimulating plant extracts.

Reconstructed human epidermis equivalents (RHE) have been developed as a clinical skin substitute and as the replacement for animal testing in both research and industry. KiPS, or keratinocytes derived from induced pluripotent stem cells (iPSCs) are frequently used to generate RHE. In this study, we focus on the mitochondrial performance of the KiPS derived from iPSCs obtained from two donors. We found that the KiPS derived from the older donor have more defective mitochondria. Treatment of these KiPS with a plant extract enriched in compounds known to protect mitochondria improved mitochondrial respiration and rendered them fully competent to derive high-quality RHE. Overall, our results suggest that improving mitochondrial function in KiPS is one of the key aspects to obtain a functional RHE and that our plant extracts can improve in this process.

Oil coating on hydrophilic surfaces from emulsions and under shear flow.

We study the formation of silicone oil coating on negatively charged hydrophilic surfaces via emulsion deposition. Cationic surfactants usually adsorb and form bilayers onto negative surfaces. As a result, direct emulsions stabilized with cationic surfactants are paradoxically poorly efficient at coating negative substrates. We show in this work an alternative and new method, still based on electrostatic attractions, to coat negative substrates. Our method consists of using emulsions stabilized with nonionic surfactants and of adding to the oil cationic additives that are non-water-soluble and of high molecular weight to minimize their solubilization in the micelles formed by the neutral surfactant. The positively charged droplets stick efficiently onto the substrates. They form monolayer and uniform coatings. We study the kinetics and the density of the resulting coating using a flow cell experiment. This technique allows us to finely analyze the influence of several physicochemical parameters.