Emulsion biopolymer capsules formed under ultrasonic treatment: synthesis mechanisms and applications

The development of effective encapsulation methods for hydrophobic compounds is a relevant interdisciplinary challenge, particularly for medicine and biotechnology where high therapeutic potential of compounds often cannot be implemented due to solubility and delivery issues. This review provides a systematic analysis of one-step ultrasonic synthesis of emulsion capsules composed of polymers. According to this approach, ultrasonic cavitation not only facilitates the formation of stable emulsions, but also initiates a cascade of physicochemical transformations of biopolymers (proteins, polysaccharides, and glycoproteins), resulting in the formation of robust shells at an interface. This review presents the first comparison and classification of shell formation mechanisms depending on the polymer type, clarifies the role of generated radicals, and highlights the synergistic effects observed in hybrid systems. Special emphasis is placed on the practical potential of this technique for the design of drug delivery systems, contrast agents, and smart materials with controlled release functionality. The bibliography includes 93 references.