Pillar6arene 12– is a dianionic and accessible host, possessing a cylindrical cavity composed of six benzene rings with ten ethoxy and two carboxylic acid groups at the top/bottom portals. The results from 1H NMR spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) measurements of bolaamphiphilic 12– in 30 mM phosphate buffer (PBS) at pH = 7.4 are in line with its self-association into spherical nanoparticles at concentrations up to 200 μM. At lower concentrations ( y) along with (b) binary and inclusion drug⊂pillararene complexes. The existence of the latter was corroborated with mass spectrometry (ESI/TOF MS). Importantly, multimeric drugx⊂pillarareney and binary drug⊂pillararene complexes constitute sizable and spherical nanoparticles (600 nm–1 μm; DLS and TEM). With the biocompatibility of nanoparticulate 12– toward HeLa cells and its capacity to capture toxic anticancer agents used in clinics thereby forming larger nanoparticles, we reason that the nanosystem described here could be developed into a platform for effective sequestration or delivery of anticancer drugs.
Karmakar et al. (2026) studied this question.