AestheFill® in Aesthetic Medicine: From Materials Science to Clinical Practice

ABSTRACT Background Injectable poly‐D, l ‐lactic acid (PDLLA; AestheFill®) is a collagen‐stimulating biostimulator increasingly used for facial rejuvenation and skin‐quality improvement. AestheFill® consists of porous PDLLA microspheres suspended in sodium carboxymethylcellulose (CMC), a formulation that influences handling, early volumization, and tissue integration. Objective To summarize the composition, mechanisms, reconstitution/dilution methods, clinical efficacy and safety, complication prevention/management, and practical comparisons relevant to AestheFill®. Methods Narrative review of preclinical studies, clinical trials, case reports, and consensus/guideline publications addressing AestheFill® properties, in vivo tissue responses, clinical outcomes, and adverse‐event management, informed by structured database searching and reference‐list screening, with emphasis on clinically actionable preparation and injection protocols. Results Preclinical evidence shows localized persistence of PDLLA microspheres at the intended plane with progressive cellular infiltration and type I collagen deposition, supporting a scaffold‐to‐tissue replacement mechanism. Randomized evaluator‐blinded comparative trials in South Korea and China demonstrate noninferior nasolabial fold correction versus hyaluronic acid comparators with favorable short‐ and long‐term safety. Outcomes are technique‐dependent: initial reconstitution should use sterile water for injection to ensure complete CMC hydration; suspension thickness should be selected according to injection plane; and injections should be delivered as small, evenly distributed aliquots to reduce maldistribution‐related nodules. Accelerated reconstitution techniques (back‐and‐forth and vacuum‐assisted hydration variants) improve workflow and suspension homogeneity. Recent guidance emphasizes ultrasonography‐assisted diagnosis and staged management for AestheFill® nodules. Rarely, vascular occlusion may cause severe ocular or neurologic sequelae. Conclusions Available evidence supports injectable PDLLA as a collagen‐stimulating filler when reconstitution and anatomy‐driven technique are standardized; further comparative trials and standardized outcomes are needed.