Noninvasive dermatological procedures for correcting age-related soft tissue defects majorly employ hyaluronic acid (HA)-based injectable filling agents. 

Details about the available HA-based products and differences relating to their rheological nature and clinical application were explained in a recent study. 

Linear HA (LHA) gels can be used along with amino acids, lipoic acid, vitamins, nucleosides or minerals to impart synergistic antiaging and antioxidant benefits (polycomponent LHA). 

HA hydrogels when produced via chemical or physical crosslinking, see increased elasticity and decreased viscosity. However, their performance depends on HA concentration, degree of crosslinking, elastic modulus, cohesivity and type of crosslinking agent employed. 

Polyethylene glycol (PEG)-crosslinked LHA, when compared to BDDE-crosslinked LHA, displays enhanced elasticity and resistance to degradation, and lower swelling rates. HA hydrogels can be stabilized by physical crosslinking without using exogenous chemical compounds or changing hyaluronans’ natural molecular structure. Hybrid cooperative HA complexes (HCC) with thermal stabilization are a formulation of high- and low-molecular-weight (H-HA and L-HA) hyaluronans, acquiring high HA concentration, low viscosity with optimal tissue diffusion and duration as a weakly crosslinked gel. Thus understanding different fillers’ properties is important in selecting the most suitable filler for distinct uses and for achieving predictable and sustainable results.

Source: Cassuto D, Bellia G, Schiraldi C. An overview of soft tissue fillers for cosmetic dermatology: from filling to regenerative medicine. Clin Cosmet Investig Dermatol. 2021;14:1857-66.