Advanced coacervation-driven nanoscale polymeric assemblies for biomedical applications

Complex coacervation, a fascinating phenomenon rooted in liquid–liquid phase separation, plays a crucial role in numerous biological systems. This intricate process involves the segregation of a liquid into two distinct phases: a coacervate phase enriched with polymers and a polymer-deficient phase comprising the remaining dilute solution. The potential of coacervates extends beyond their natural occurrence in biological systems, as they possess the capability to encapsulate various types of biomolecules in an aqueous solution, obviating the need for organic solvents. Consequently, considerable efforts have been devoted to designing functional nanoscale coacervate-driven assemblies using both natural and synthetic polymers for a myriad of applications. In this review, we provide a synthesis and discussion of the formation of nanoscale polymeric assemblies driven by complex coacervation. This exploration delves into the fundamental driving forces underpinning the phenomenon and elucidates the diverse fabrication strategies employed. The various biomedical applications of these assemblies are highlighted, with a focus on their roles as drug carriers, gene delivery vehicles, antimicrobial agents, theranostic platforms, mucoadhesives, and nanoreactors. This review aims to contribute to a deeper understanding of coacervation-driven nanoscale assembly systems and their potential impact on the field of biomedical science and technology.