Traditional macrocyclic hosts have finite cavity sizes, generally 5-10 , which are commonly adaptive to recognize small guests rather than biological macromolecules. Here two water-soluble large-sized quaterphen [n]arenes (WQPns, n = 3, 4) were designed and synthesized. These two hosts present significantly distinct recognition abilities. Specifically, they could strongly complex an antimicrobial peptide, pexiganan (PXG) with the association constants (K a ) of (4.20 AE 0.23) 10 4 M À1 for PXG/WQP3 and (2.46 AE 0.44) 10 5 M À1 for PXG/WQP4. Complexation of PXG by WQP3 and WQP4 served to decrease the hemolysis of PXG in rabbit red blood cells in a statistically significant way. Furthermore, host-guest complexation was shown to substantially enhance metabolic stability of PXG in presence of proteinase K, rat plasma and liver or kidney homogenates.

Intelligent drug delivery systems (DDSs) that can improve therapeutic outcomes of antitumor agents and decrease their side effects are urgently needed to satisfy special requirements of treatment of malignant tumors in clinics. Here, the fabrication of supramolecular self-assembled amphiphiles based on the host−guest recognition between a cationic water-soluble pillar[6]arene (WP6A) host and a sodium decanesulfonate guest (G) is reported. The chemotherapeutic agent doxorubicin hydrochloride (DOX) can be encapsulated into the formed vesicle (G/WP6A) to construct supramolecular DDS (DOX@G/WP6A). WP6A affords strong affinities to G to avoid undesirable off-target leakage during delivery. Nanoscaled DOX@G/WP6A is capable of preferentially accumulating in tumor tissue via enhanced permeability and retention (EPR) effect. After internalization by tumor cells, the abundant adenosine triphosphate (ATP) binds competitively with WP6A to trigger the disintegration of self-assembled vesicles with the ensuing release of DOX. In vitro and in vivo research confirmed that DOX@G/WP6A is not only able to promote antitumor efficacy but also reduce DOX-related systemic toxicity. The above favorable findings are ascribed to the formation of ternary selfassembly, which profits from the combination of the factors of the EPR effect and the ATP-triggered release.

Poisoning by organophosphorus agents (OPs) is a serious public health issue across the world. These compounds irreversibly inhibit acetylcholinesterase (AChE), resulting in accumulation of acetylcholine (ACh) and overstimulation of ACh...

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