What is Cross-Linking?
In its natural form, unbound hyaluronic acid forms a liquid made of highly-hydrated individual polymers (chains) that are metabolized in the body in just 12 hours. Cross-linking refers to a process in which the individual chains of hyaluronic acid are chemically bound (or “cross-linked”) together, transforming the liquid hyaluronic acid into a soft solid, or “gel.” The firmness of the gel depends on the degree of cross-linking of the individual hyaluronic acid chains. The body metabolizes cross-linked hyaluronic acid more slowly, resulting in a longer duration of effect when hyaluronic acid is used therapeutically.
Hyaluronic Acid – Since 2003
Physicians have been developing ways to restore volume and structure to aging skin using a variety of approaches for over 100 years. Past fillers included paraffin, silicone and collagen injections.
In the 1930s, researchers discovered a natural substance in the body that they named hyaluronic acid, and they found that it plays a key role in numerous areas of the body including the maintenance of skin volume and hydration, eye volume and shape and joint lubrication and cushioning.
In the decades since, numerous therapeutic and aesthetic uses have been developed for this versatile natural substance. In 2003, the U.S. Food and Drug Administration (FDA) approved the first hyaluronic acid dermal filler for the correction of facial wrinkles and folds, such as nasolabial folds (the folds running from the sides of the bottom of the nose to the outer corners of the mouth).
Today, hyaluronic acid-based dermal fillers are the fastest growing non-invasive aesthetic procedure in the United States, according to the American Society for Aesthetic Plastic Surgery.1
1 American Society for Aesthetic Plastic Surgery. February 24, 2006