Visual, Ultrasonographic, and Microscopic Study on Hyaluronic Acid-Based Gel

Abstract

Background: Hyaluronic acid (HA) fillers are commonly used for enhancement of lips, and for softening fine lines and correcting skin depressions.

Objective: This study sought to investigate whether the Vycross^&trade; technology used for Volbella^&trade; gel resulted in a cohesive gel, as documented in our previous studies with three other HA fillers (Restylane^&reg; NASHA^&trade; [Q-MED, Uppsala, Sweden], Esthélis^&reg; Basic CPM™ [Anteis SA, Geneva, Switzerland], and Juvéderm^&reg; Ultra 3 using Hylacross technology [Allergan, Irvine, CA, USA]).<br/>

Method: The "resistance traction test" and "cohesiveness test" were conducted according to standard methods. Juvéderm^&reg; Volbella^&trade; gel was injected into the buttock area, both in the superficial reticular and mid-reticular dermis. Tissue samples were analyzed at days 0, 15, and 90 by histology and immunohistochemistry, and visualized using electron microscopy. For Volbella^&trade; gel, the same ultrasound devices as previously used were employed.<br/>

Results: Prior to staining, Volbella^&trade; gel presented resistance to spreading, suggesting a certain degree of cohesiveness. When smeared between two slides and following toluidine blue staining, the gel was visible through the microscope in the form of multiple tiny discrete particles, possibly resulting from gel desintegration. At 1/3 dilution with saline serum, Volbella^&trade; gel disintegrated into several lumps, whereas at 1/1 dilution, Volbella gel appeared more cohesive. Yet when adding one drop 70% ethanol, the gel resembled a poorly defined magma, with numerous small lumps. On ultrasound, Volbella^&trade; gel was found to leak in the hypodermis. On histological analysis, Volbella^&trade; gel was visible as pools of variables sizes, particularly in the superficial and mid-reticular dermis, but also hypodermis.<br/>

Conclusion: Juvéderm Volbella^&trade; gel appears to be a gel characterized by low-medium cohesiveness. The study findings, combined with our previous work, show that HA fillers using Vycross^&trade; technology are not ideally suited for superficial use, unlike HA fillers using CPM technology^&trade;. <br /><br /> <em>J Drugs Dermatol.</em> 2016;15(9):1092-1098.