Supramolecular assembly of glycyrrhizic acid for multifunctional biomaterials applications

Natural herbal small molecules with remarkable supramolecular self-assembly behavior are particularly attractive in fabricating multifunctional biomaterials. Glycyrrhizic acid (GA), a natural food-grade triterpenoid saponin with inherent biological effects and excellent biocompatibility and biodegradability, exhibits hierarchical self-assembly in aqueous solutions, leading to the formation of two-dimensional nanofibrils and further a supramolecular gel network. The controllable GA self-assembly makes it highly suitable for the development of versatile functional biomaterials (e.g., nanoparticles and hydrogels). Herein, we first review the structural characteristics and self-assembly mechanism of GA in aqueous solutions, with particular emphasis on its stimuli-responsive assembly behavior. Subsequently, a systematic and comprehensive overview of the pathways for fabricating advanced biomaterials and the three major classes of GA-based supramolecular materials are presented. Finally, the carrier-free bioactive substances delivery, antibacterial efficiency, wound healing, and biosensing applications of GA-based multifunctional materials are summarized and highlighted. Future scientific challenges and opportunities are also discussed to provide insights into the rational design and development of next-generation GA-based multifunctional biomaterials for biomedical applications.