Small proteoglycans in the skin: new targets in the fight against skin aging

Abstract

IFSCC Magazine, 11 (2008) (1) 21-29 Proteoglycans take an important part in tissue homeostasis. In the skin, Proteoglycans are present in the extracellular matrix of dermis, particularly with lumican which plays an important role in dermal homeostasis. In the epidermis, several small proteoglycans such as the syndecans are synthesized and play an important role in keratinocyte activation. There is much data on the alteration during skin aging of the synthesis and structure of glycosaminoglycans and some proteoglycans but little information on small proteoglycans, in particular lumican and syndecan-1.We recently observed a decrease in the synthesis of these two small proteoglycans with aging. We confirm in this work the decrease in lumican in dermis and syndecan-1 in epidermis with aging. These proteoglycans represent original important targets for cosmetology in the fight against skin aging. In different in vitro models, two synthetic acetyl tetrapeptides, AcTP1 and AcTP2, stimulate the synthesis of lumican and syndecan-1, respectively. The beneficial action of AcTP1 on skin thickness and firmness and of AcTP2 on epidermal cohesion has been confirmed in vivo. IFSCC Magazine, 11 (2008) (1) 31-34 A water-in-powder cosmetic is one in which a large amount of water is encapsulated in a powder. In this study we describe the development of this type of cosmetic. We first focused on the hydrophilic/hydrophobic balance of the nano-sized powder surface. We looked at surface state of powders in the gas adsorption test and discovered functional powders that have an optimized balance of hydrorepellency and hydrophilicity due to fractal surface and free hydroxyl groups, respectively. Using this material we created a new powder technology that can encapsulate a large quantity of water in a stable structure. We also looked at how the powders encapsulated water by observing them with wet-SEM and how the encapsulated water is stabilized by measuring the water mobility with 17O-NMR. Based on these result, we developed a new technology with water and powder. By encapsulating a large amount of water, we achieved a cosmetic with many unique characteristics: The powder cosmetic can become a liquid by application of friction on skin, it is convenient to use and provides moist, cool feel. It also functions as an excellent makeup by spreading smoothly on skin to form a uniform makeup coating.

Role of topical peptides in preventing or treating aged skin

“…Pauly et al. [42] evaluated two new synthetic peptides: acetyl tetrapeptide‐9 and ‐11 ((AcTP1, AcTP2, respectively). In vitro study revealed an increase in collagen I and lumican synthesis for AcTP1 and stimulation of keratinocyte cell growth and syndecan‐1 synthesis for AcTP2.…”

“…AcTP1 was also more effective than placebo. AcTP2 had significant effect on biomechanical parameters of the superficial layers of epidermis and 5–10% better effect than placebo [42].…”

Improvement of the methods for skin mechanical properties evaluation through correlation between different techniques and factor analysis

“…The device generates negative pressure, which can be varied between 20 and 500 mbar . The skin area to be measured is drawn into the aperture of the probe as a result of this negative pressure, causing a vertical deformation . The penetration depth of the skin into the aperture is determined without contact by an optical measuring system.…”

“…Afterwards the negative pressure is switched off and the skin returns to its original shape. The curve (distance in mm vs time in s) points out the viscoelastic properties of the skin and allows the calculation, for example, of the following parameters: (Fig. ):…”

The tetrapeptide N-acetyl-Pro-Pro-Tyr-Leu in skin care formulations—Physicochemical and release studies

“…1) is used in cosmeceutical compositions as an anti-aging active ingredient (Rodrigues et al, 2008). Pauly et al (2008) revealed in in vitro studies that AcPPYL commercially known as acetyltetrapeptide-11 stimulates keratinocyte cell growth and syndecan-1 synthesis. In vivo studies showed a significant increase in the biomechanical parameters of the superficial layers of epidermis.…”