Recent progress in cancer detection and therapeutic applications of calixarene- and pillararene-based systems

Macrocycles, such as calixarenes and pillararenes, have received more focus as potential therapeutic agents and drug carriers. They can solubilize/encapsulate different anti-cancer drugs by host-guest interactions or self-assembly. Good chemical stability, good compatibility, responsiveness to external stimuli and low toxicity to normal cells are properties that make these macrocycles good candidates for cancer detection and therapy. This review focuses on strategies developed for cancer detection and therapeutics by calixarenes and pillararenes over the past decade (from 2015 to 2025). Cone calix[4]arene platform has been the most widely investigated, but examples of calix[5], [6], [8]arenes have also been reported. Pillar[n]arenes, like calixarenes, exist in a range of homologues up to pillar[10]arene, however, pillar[5]arenes and pillar[6]arenes have cavity sizes most suited to drug encapsulation. Developments and applications in biosensing, bioimaging, drug delivery systems and cancer therapy are presented based on these macrocycles. Finally, conclusions and future perspectives of these macrocyclic compounds with anti-cancer activity are also provided.