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Novel claims for stem cell targeted cosmetics
Margret Ebauer PhD, Manager of Contract Research and Testing, CELLnTEC Advanced Cell Systems, discusses the importance of in vivo and in vitro approaches for stem cell related claims
Adult stem cells are located in specific niches within each tissue. In the skin, they can be found both in the epidermis and the dermis, and play important anti-ageing and regenerative roles. In addition, epidermal stem cells play a key role in wound healing. Even with regenerative stem cells, with age the skin sags, wrinkles, and thins. It also heals more slowly. This decline in regenerative potential is a hallmark of ageing and results from age-related changes in tissue-specific stem cells. A number of innovative cosmetic ingredients designed to protect skin stem cells and delay skin ageing have been recently launched. Yet, stem cells represent only a small fraction of the total cells in the epidermis, making it very difficult to demonstrate a specific stem-cell related effect. Epidermal stem / progenitor cells can be found in the bulge region of the hair follicle and in the basal layer (Fig. 1). Epidermal stem cells are now known to regenerate the epidermis, hair follicles and sebaceous glands. In addition, epidermal stem cells
also play a key role in wound healing. If damage occurs, bulge stem cells rapidly migrate towards the injury where they multiply, differentiate, and regenerate wounded skin. Dermal stem cells, responsible for skin maintenance
and regeneration, are now the target of increased research activity. Progenitor cells derived from the dermis have been found to exhibit various stem cell- like characteristics, for example, generation of new dermal cells for tissue maintenance, wound-healing and hair follicle morphogenesis. Recent research has shown that these cells reside in the dermal papillae of the hair follicle (see Fig. 1) and express specific markers like Sox2 and versican (Fig. 2). Through the use of novel in vitro models it is now possible to evaluate the effect of cosmetic actives directly on progenitor and stem cells residing in dermis and epidermis. Using a new technique known as Progenitor Cell Targeting (PCT), it is now possible to establish enriched cultures of progenitor / stem cells and maintain them for extended periods in vitro.
This technique uses specialised culture media designed to select particular cell populations (such as progenitor / stem cells) by accurately mimicking the micro-environment these cells experience in vivo (known as the niche environment). Whilst the overall effect of new cosmetic
ingredients may be assessed using in vivo models, these approaches are typically not sufficient to support novel claims of stem-cell associated activity. Through the use of novel in vitro models it is now possible to evaluate the effect of cosmetic actives directly on the progenitor and stem cells involved in skin renewal. Thus by combining in vivo and in vitro approaches, not only the visible effects of a compound can be investigated, but also its influence on underlying regenerative mechanisms. In this way, strong scientific claim support for
effect of cosmetic actives on the progenitor and stem cells can be provided.
CELLnTEC Advanced Cell Systems, Stand V21
A
B
Figure 1
Schematic representation of skin’s structure. Epidermal stem cells can be found in the basal layer of the epidermis, and in the bulge region of the hair follicle. Stem cells in the bulge are responsible for growth and regeneration of the epidermis, hair follicle, and sebaceous gland.
Figure 2
(A) Dermal stem cell marker Sox2 (green) detection in dermal papilla derived cells.
(B) Nuclear staining (blue) was used as counter stain
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