New Skin-Relevant Cell Coculture Model With Stratum Corneum-Like Layer.

Two-dimensional (2D) cell culture is an important tool in the discovery of skin-active agents. Fibroblasts and keratinocytes, more rarely fibroblast-keratinocyte cocultures, are usually used for that purpose, where test compounds are added by mixing with the overlaying growth medium. However, such an approach is suboptimal because it lacks the component.

Synthesis and new skin-relevant properties of the salicylic acid ester of bakuchiol.

Bakusylan (bakuchiol salicylate) is a bipartite compound obtained by merging two skin-active entities with complementary bioactivities-bakuchiol and salicylic acid-for the purpose of generating a new class of functional retinoids with enhanced skin benefits. Here, we describe its preparation process and report that pure bakusylan exhibits potential for an improved permeation through the stratum corneum, enhances type IV collagen gene expression in organotypic skin substitutes containing both epidermal and dermal layers, and upregulates this protein in adult human dermal fibroblast cultures. The mechanism of action underlying these effects appears to involve the components of the IP3K/Akt signaling pathway selectively implicated in the maintenance of skin integrity, further underlying the suitability of this ester for skin care applications requiring enhanced cutaneous permeation targeting the dermal-epidermal junction.

Tetrahexyldecyl Ascorbate (THDC) Degrades Rapidly under Oxidative Stress but Can Be Stabilized by Acetyl Zingerone to Enhance Collagen Production and Antioxidant Effects.

Tetrahexyldecyl Ascorbate (THDC) is an L-ascorbic acid precursor with improved stability and ability to penetrate the epidermis. The stability and transdermal penetration of THDC, however, may be compromised by the oxidant-rich environment of human skin. In this study, we show that THDC is a poor antioxidant that degrades rapidly when exposed to singlet oxygen.