Injectable Biostimulator in Adipose Tissue: An Update and Literature Review

Injectable biostimulatory agents such as poly-L-lactic acid (PLLA), polycaprolactone (PCL), and calcium hydroxyapatite (CaHA) have emerged as key tools in regenerative aesthetics due to their ability to stimulate adipogenesis and adipocyte metabolic activity, enhance collagen production, and improve dermal quality. This review aimed to provide an updated synthesis of the role of these agents in adipocyte stimulation, focusing on their mechanisms of action, clinical efficacy, and therapeutic applications. A comprehensive search of the MEDLINE, PubMed, and Ovid databases was conducted for studies published from 2018 onward, including in vitro and in vivo experiments, randomized controlled trials, and observational studies, which were evaluated according to the Oxford Centre for Evidence-Based Medicine hierarchy. The findings demonstrated that PCL promotes adipose-derived stem cell differentiation and extracellular matrix remodeling, while PLLA exhibits dual effects on collagen synthesis and adipocyte stimulation, with clinical trials such as the SPLASH study confirming significant improvements in dermal thickness and adipogenesis. CaHA provided immediate volumizing benefits with long-term tissue regeneration, and innovative approaches including combination therapies and novel injection protocols expanded clinical applications. Overall, PLLA, PCL, and CaHA represent effective and versatile biostimulatory agents that support natural and durable outcomes in aesthetic practice. Nevertheless, the absence of large-scale trials and standardized protocols highlights the need for further research to optimize safety, efficacy, and long-term treatment strategies.