An Insight on Pillararene-Functionalized Mesoporous Silica Nanoparticles for Targeted Drug Delivery and Theranostics in Cancer.

Pillararenes, a novel class of pillar-shaped macrocyclic hosts, have expanded from the sole domain of supramolecular chemistry and have attracted immense interest among scientists due to their remarkable characteristics, such as symmetrical structures, electron-rich cavities, tunable functionalization, and unique host-guest interactions. Based on host-guest chemistry, in collaboration with other molecular systems, researchers have focused on the construction and development of pillararene-based mesoporous silica nanoparticles (MSNs). Pillararene-functionalized MSNs have gained considerable attention due to their distinct topological and chemical structures, as well as favorable physicochemical properties. This review discusses the synthesis of pillararene-MSN hybrid systems by integrating pillararenes with MSNs, which offer large surface areas and abundant active sites. Furthermore, recent advancements in their applications are explored, including drug delivery, molecular recognition, biosensing, imaging, and stimuli-responsive cargo release triggered by pH, competitive agents, temperature, near-infrared light, and acetylcholine. We also highlighted current challenges and future perspectives for the clinical translation of pillararene-MSN-based drug delivery systems.