Hyaluronic Acid, Is A Natural Occurring Substance, That Is Found In Virtually All Of Your Body’s Cells.
HA clusters most densely in the skin (50%), however it is also found in cartilage, connective tissue and in the synovial fluid that lubricates the body’s joints.
HA is highly soluble and can hold water in greater quantities than its own weight.
It’s Immunological tolerance, ability to assist in the regeneration of collagen and excellent absorption properties make the HA molecule an excellent candidate for volumising and mositurising the skin.
However, HA in its natural state has a rapid turnover through enzymatic and free radical degradation with a half-life of 24hr in vivo.
Therefore to be considered as a cosmetic treatment, HA must be chemically modified to prevent decomposition. This process transforms HA from a liquid into a gel by crosslinking Hyaluronic acid polymer chains to one another. This crosslinking modification allows HA to fill wrinkles and maintain it’s shape for a longer period of time.
The more links that are generated through the crosslinking reaction, the longer it takes for the skin to break down the cross-linked Hyaluronic acid.
Non Cross-linked HA
HA dermal fillers can be classified into two main groups: Cohesive (monophasic) or non-cohesive (Biphasic) depending on the method of development. The cohesive (monophasic) fillers are composed of a single phase of HA, which may be cross-linked once (mondensified) or continuously (polydensified). The Cohesive monodensified filler is characterised by a highly cross-linked smooth gel.
Cohesive polydensified fillers (Revolax) are characterised by regular densities of cross-linked HA zones. This ensures optimal spreading of the gel into surrounding tissue, allowing larger spaces to be filled with denser parts of the gel and finer pericellular tissue spaces to retain low-density gel in a structured yet malleable form.