Advanced Concepts in Rheology for the Evaluation of Hyaluronic Acid–Based Soft Tissue Fillers

Abstract

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Efficacy and Safety of a New Resilient Hyaluronic Acid Filler in the Correction of Moderate-to-Severe Dynamic Perioral Rhytides: A 52-Week Prospective, Multicenter, Controlled, Randomized, Evaluator-Blinded Study

“…Biomechanical characterization of RHA fillers has demonstrated their resilient behavior, that is, improved capacity to recover their original shape and mechanical features after compression, stretching, or bending. 11 , 13 Other investigators have reported homogeneous tissue integration of RHA fillers after intradermal injection. 14…”

Injection techniques for midface volumization using soft tissue hyaluronic acid fillers designed for dynamic facial movement

“…The dynamic strength of a gel describes the ability of the gel to maintain its physical integrity (G’) over a wide range of dynamic forces. The complex modulus (G*) of a gel in a dynamic environment better reflects the mechanical resistance of the gel 15 . A filler also needs to move and adapt to a dynamic face for a natural look.…”

“…A filler also needs to move and adapt to a dynamic face for a natural look. The stretch parameter reflects the ability of the gel to deform and adapt to stress (eg, tissue stretching when smiling) 15 . Dynamic fillers require the rheological properties of both strength and stretch to optimally treat specific areas of the face.…”

“…It has the highest dynamic strength value, which makes it well suited for injection in areas where mechanical resistance is important (eg, the midface). In addition, RHA 4 has sufficient stretch properties that enable it to be injected into both deep (static) and superficial (dynamic) facial compartments 15 …”

Physico-Chemical Characterization and In Vitro Biological Evaluation of a Bionic Hydrogel Based on Hyaluronic Acid and l-Lysine for Medical Applications

“…Therefore, for specific medical applications, e.g., restoration of age-related volume loss in facial soft tissue, it is important to stabilize HA through a crosslinking process, which turns the otherwise liquid viscous solution into a solid-like biohydrogel, that resembles the natural structure of HA in the body and allows one to tailor mechanical, biological and rheological properties (including injectability) and resorption time [ 18 , 19 ].…”