Young skin is plump skin. It is described by its volume, bounce and elasticity. In aesthetics, we say it is deeply hydrated. These characteristics are due to the presence of an essential molecule: hyaluronic acid.
Hyaluronic acid is found naturally in the connective tissues (skin, cartilage, cornea, etc). This polymer is produced by skin cells that synthesize two molecules derived from glucose: N-Acetyl-Glucosamine-6-Phosphate, or NAG-6P, and glucuronic acid, in a repetitious sequence.
Hyaluronic acid plays an important role, because as a highly absorbent sponge, it captures large amounts of water and retains it deep within the skin at the heart of the dermis, forming an elastic gel. This contributes to the volume and elasticity of young skin.
With age, the amount of hyaluronic acid in the dermis decreases —its quantity in the skin drops by half between the ages of 20 and 50. In effect, cells are no longer able to produce NAG-6P in sufficient quantities, so the amount of hyaluronic acid in the dermis gradually decreases. In addition, hyaluronic acid naturally breaks down more quickly over time. The skin is no longer deeply hydrated and loses its bounce.
Hyaluronic acid in cosmetology
As mentioned earlier, hyaluronic acid is a sugar polymer. Its large molecule cannot penetrate through to the dermis and therefore cannot replace natural hyaluronic acid. However, thanks to its exceptional ability to retain water, it has long been popular among manufacturers. They have at their disposal two types of hyaluronic acid molecules—large molecules with high molecular weight, or smaller molecules—which boast different effects on the skin.
High molecular weight molecules remain on the surface of the epidermis and form a permeable film that helps maintain hydration and limits transepidermal water loss (TEWL). This film also has a plumping effect, firming and smoothing the skin’s surface thus temporarily reducing the appearance of fine lines and wrinkles.
The smaller molecules, which are actually hydrolyzed hyaluronic acid, will penetrate the upper layers of the skin and promote regeneration and healing.
Hyaluronic acid in medical aesthetics
In recent years, applications of hyaluronic acid have extended beyond the scope of cosmetology. In its cross-linked form—the cross-linking is a chemical process that connects several hyaluronic acid molecules together to ensure a longer lifespan—it is one of the most useful molecules in medical aesthetics. Injected into wrinkles, it can be used as a filler, by producing volume under the furrows.
Third generation hyaluronic acid: the first injection-free wrinkle filler
Recently, a new generation of hyaluronic acid has emerged. Rather than using the hyaluronic acid molecule, researchers have developed a precursor to hyaluronic acid. It is NAG-6P obtained by enzymatic conversion of natural N-acetyl-glucosamine, using a green biotechnological chemical process.
Scientific studies have demonstrated that topical application of NAG-6P results in three synergistic actions:
• it reactivates the natural synthesis of hyaluronic acid throughout the papillary dermis
• it restarts the communication between keratinocytes and fibroblasts and boosts the fibroblasts
• it strengthens and improves the dermal-epidermal junction (DEJ)
The resulting effect is anti-aging, through volumizing, deeply plumping, firming and regenerating the skin.
This major breakthrough in anti-aging care can boost the natural production of hyaluronic acid in the skin—for a deep moisturizing and volumizing effect—and reproduce the effects of advanced technologies used in medical aesthetics for filling wrinkles.
Did you know?
Hyaluronic acid has long been used in cosmetology. Originally, manufacturers used hyaluronic acid extracted from rooster combs. Nowadays, as technology has evolved, it is synthetically produced using biotechnology.
Isabelle Villeneuve is scientific director—head of innovation at Laboratoire Dr Renaud. She has been actively participating in the development of Laboratoire Dr Renaud since 1995.