“…The MSN vehicles capped with supramolecular nanovalves have been extensively studied, in which cyclodextrins, 8−13 calixarenes, 14,15 and cucurbiturils 16−24 encircled the thread-like molecules immobilized on the MSN surface. The nanovalves can be activated for controlled release with a variety of stimuli, such as pH, 8,13,[16][17][18]20,23,24 redox, 13,19 light, 15,22 enzyme, 10,11,14,21 and competitive binding 20,21 in aqueous solutions.…”