Dermal Fillers: Gel Properties
Hyaluronic Acid fillers are widely used in aesthetics. Manufacturers of dermal fillers design their products with specific properties and use proprietary technology to modify their products unique to each line of filler.
These properties include hyaluronic acid concentration, gel firmness, cohesivity, flexibility, and the degree of cross-linking.
Hyaluronic Acid Concentration: defined as the total weight of hyaluronic acid in 1 mL of product.
Gel Firmness/Viscosity (G’): a measure of the product's ability to resist deformation. The higher the G’ the firmer the gel.
Gel Cohesivity/Flexibility: a measure of the product’s ability to remain intact with stretching forces and facial movements.
Crosslinking: Manufacturing processes use different hyaluronic acid substrates and concentrations and types of crosslinking reactions in a variety of combinations. This establishes a unique basis and profile for each product. It is the basis for mechanical strength and product longevity.
Today, commercially available hyaluronic acid fillers are all manufactured through a similar process which involves isolating hyaluronic acid in its original form by fermentation of Streptococcus sp. bacteria and then linearizing individual hyaluronic acid chains. Once isolated, the chains will undergo crosslinking to stabilize the gel and prevent degradation.
Cross-linking technologies:
Cohesive Polydensified Matrix (CPM): non-uniform cross-linking that undergoes two rounds of crosslinking.
Hyalcross: Proprietary technology cross-links hyaluronic acid molecules (uniform size).
Vycross: Proprietary technology cross-links hyaluronic acid molecules (small and large sizes) to create a smooth and efficiently crosslinked filler.
Nonanimal stabilized hyaluronic acid (NASHA): the closest to your body’s hyaluronic acid with minimal cross-linking.
XpresHAn Technology: cross-linked hyaluronic acid designed for movement and expression.
Resilient Hyaluronic Acid: uses a gentle manufacturing process to help preserve the natural structure of hyaluronic acid, resembling your body’s hyaluronic acid, designed to be resilient and adapt to facial movement.
Thixofix crosslinking technology designed for easy injection