Coacervate-Based Delivery Systems: Bridging Fundamentals and Applications

Abstract Coacervate-based drug delivery systems, inspired by liquid–liquid phase separation, have emerged as a flexible platform for encapsulating and controlling the release of therapeutic agents such as nucleic acids, proteins, growth factors, and small molecules. Their capacity to react to exogenous and endogenous stimuli, such as pH and temperature, allows for accurate adjustment of the drug release profile and targeted delivery. Nonetheless, despite these advantages, poor stability in biological environments continues to pose a major obstacle, impacting drug retention and the effectiveness of therapies. This instability further complicates large-scale production, as ensuring uniform coacervate characteristics across different batches poses a significant challenge. Recent developments in molecular engineering, such as polyelectrolyte complexation and stimuli-responsive modifications, have significantly improved the stability and functionality of coacervates. This review offers an in-depth examination of the principles behind coacervate formation, their structural classifications, and the physicochemical properties that affect their effectiveness in drug delivery applications. Recent advancements in formulation techniques and the latest trends in combining nanotechnology with computational modeling are examined, emphasizing their potential to enhance coacervate behavior in biomedical applications. Furthermore, this review explores recent developments in gene therapy, regenerative medicine, and targeted drug delivery, highlighting the promising applications of coacervates in future therapeutic innovations. This work points out the essential challenges and opportunities that will drive the future evolution and clinical application of coacervate-based delivery systems by integrating foundational insights with technological progress.