Biochemistry, Physiology, and Tissue Interactions of Contemporary Biodegradable Injectable Dermal Fillers

BACKGROUND: Injectable dermal fillers are becoming increasingly popular for soft tissue augmentation and rejuvenation. Most contemporary biodegradable products are derived from hyaluronic acid, calcium hydroxylapatite, or poly-L-lactic acid. Achievement of desired cosmetic outcomes is largely dependent on selection of the optimal injectable product based on the chemical composition, the physiologic interactions with surrounding tissue, product longevity, and a thorough understanding of potential adverse reactions. OBJECTIVE: To review and describe the biochemistry, physiology, and tissue interactions of the most commonly used contemporary biodegradable dermal fillers. METHODS: A thorough review of the literature was performed with additional review of pertinent clinical cases and corresponding histopathology. RESULTS: This article provides a comprehensive review of the biochemistry, physiology, and potential tissue interactions of the most commonly used biodegradable dermal fillers. The underlying biochemical properties of each product and how they contribute to specific physiologic and adverse tissue reactions is described. CONCLUSION: Understanding of the innate differences in the physical properties, and physiologic responses to soft tissue fillers allows clinicians to achieve desired aesthetic outcomes with fewer adverse events.