Multistimuli Responsive Core–Shell Nanoplatform Constructed from Fe3O4@MOF Equipped with Pillar[6]arene Nanovalves

Abstract An intelligent theranostic nanoplatform based on nanovalve operated metal–organic framework (MOF) core–shell hybrids, incorporating tumorous microenvironment‐triggered drug release, magnetic resonance imaging (MRI) guidance, sustained release, and effective chemotherapy in one pot is reported. The core–shell hybrids are constructed by an in situ growth method, in which Fe 3 O 4 particles with superior abilities of MRI and magnetic separation form the core and UiO‐66 MOF with high loading capacity compose the shell, and then are surface‐installed with pillararene‐based pseudorotaxanes as tightness‐adjustable nanovalves. This strategy endows the system with the ability of targeted, multistimuli responsive drug release in response to pH changes, temperature variations, and competitive agents. Water‐soluble carboxylatopillar[6]arene system achieved sustained drug release over 7 days due to stronger host–guest binding, suggesting that the nanovalve tightness further reinforces the desirable release of anticancer agent over a prolonged time at the lesion site.