Research progress on calixarene/pillararene-based controlled drug release systems.

Intelligent controlled-release drug delivery systems that are responsive to various external stimuli have garnered significant interest from researchers and have broad applications in the biomedical field. Aromatic macrocycles, including calixarenes and pillararenes, are considered ideal candidates for the construction of supramolecular drug delivery systems because of their simple synthesis, ease of modification, electron-rich and hydrophobic cavities, and highly selective molecular recognition. In recent years, numerous supramolecular drug delivery systems utilizing aromatic macrocycles have been developed. This review article provides an overview of the advancements of controlled drug release systems based on host-guest selective recognition, self-assembly, and nano-valves by the use of of calixarenes and pillararenes from five perspectives: pH, light, enzyme, hypoxia, and multi-stimuli combination responses. Furthermore, the article projects the future clinical application prospects of controlled-release technologies, with the aim of offering a reference for the utilization of aromatic macrocycles in drug-controlled release applications.