No abstract

Dual-cavity baskets, carrying six γ-aminobutyric acids sequester anticancer anthracyclines in a cooperative manner to be of interest for creating nano-antidotes.

Pillar[5]quinone (PQ[5])‐based porous polymer has been prepared by crosslinking and oxidating pillar[5]arene (PA[5]). Quinone was used as an unorthodox ligand to load palladium‐catalyst with high loading ratio (up to 12.0 wt %). Catalyst was well dispersed on solid support in the form of Pd2+‐specie. Pd‐loaded PQ[5]‐based heterogeneous catalyst was highly efficient for Suzuki‐coupling reactions (22‐ to 1485‐fold higher than Pd/C based on turnover frequency). It was superior compared to other existing heterogeneous catalysts for selective catalytic reaction. This heterogeneous catalyst had good thermo‐stability, and could be reused and recycled.

Acetal-functionalized pillar­[5]­arene (Ac-PA­[5]) was prepared as a pH-responsive biomaterial. This biomaterial could be fabricated into nanoparticles with a narrow size distribution by an emulsion protocol. PA[5]-based nanoparticles were used to deliver anti-tumor drugs (paclitaxel and doxorubicin) in vitro. PA[5]-based nanoparticles were discovered to be a versatile drug delivery system (DDS) to incorporate a fluorescent dye (fluorescein) or a targeting group (folic acid) via host–guest interactions. The resulting DDS could be used for the purpose of bioimaging or targeted delivery. Acetal-functionalization renders the system acid-labile to release encapsulated cargo during cell internalization, which is confirmed by confocal laser scanning microscopy (CLSM). A folic-acid-modified DDS shows a 5.1-fold enhancement in bioactivity in vitro due to the targeting effect. This DDS is a platform to conveniently integrate multiple functions.

We report "pro-guest" and acyclic cucurbit[n]uril conjugated polymers as supramolecular drug delivery systems (DDSs). These supramolecular DDSs could encapsulate anti-tumor drugs. Under acidic conditions, an acid-labile "pro-guest" degraded to become a "competing guest", which displaced and released the encapsulated drug at a tunable rate.