Green microparticles based on a chitosan/lactobionic acid/linoleic acid association. Characterisation and evaluation as a new carrier system for cosmetics.

The association chitosan/linoleic acid/lactobionic acid in aqueous solution spontaneously led to the formation of stable microparticles with a liquid hydrophobic core consisting of linoleic acid surrounded by a shell of chitosan/lactobionic acid. The originality of the microparticles arises from the fact that they are formed by the association of three ingredients of cosmetic interest, including a skin penetration enhancer (linoleic acid). Dynamic light scattering (DLS) measurements showed microparticles with a mean diameter of 1-2 µm. The presence of a hydrophobic liquid core was observed by transmission electron microscopy (TEM). The ability of these microparticles to encapsulate phenylethyl resorcinol, a hydrophobic skin lightener, was evaluated and its encapsulation was confirmed thanks to T2 measurements and nuclear Overhauser effects (nOe) signs.

Acceleration of keratinocyte differentiation by transient receptor potential vanilloid (TRPV6) channel activation.

BACKGROUND: Numerous studies have demonstrated the beneficial effect of Avène Thermal Spring Water (TSW) in dermatological diseases but the molecular mechanisms remain unknown. The objective of the present study was to evaluate the effect of Avène TSW on the morphological and molecular features related to the more advanced status of differentiation of human keratinocytes. MATERIAL AND METHODS: Normal human keratinocytes (NHK) were differentiated in medium powder reconstituted with Avène TSW and assessed by RT-PCR and immunohistochemistry. Calcium entry was measured by a Fura-2 AM probe. TRPV6 channel were detected by immunohistochemistry, RT-PCR and western blot. RESULTS: Treatment of NHK with Avène TSW led to an enhanced constitutive calcium entry that resulted in the increased expression of involucrin and cytokeratins 1 and 10. This enhanced constitutive calcium entry in Avène TSW-treated keratinocytes was mediated by the TRPV6 calcium channel. Moreover, Avène TSW-mediated calcium entry was due to the increase in TRPV6 expression as well as the channel abundance at the cell membrane. CONCLUSIONS: An other mechanism of action of Avène TSW is described. Avène TSW treatment induced an enhanced constitutive calcium entry mediated by TRPV6 channel leading to the acceleration of human keratinocytes differentiation.