Ultrastable and Versatile Layer‐by‐Layer Coating Based on Kinetically Trapped Host–Guest Complexation for Mesoporous Silica Nanoparticles

Abstract A highly stable, versatile, and stimuli‐responsive layer‐by‐layer coating is constructed for mesoporous silica nanoparticles (MSNs) using kinetically trapped host–guest complexation. The ultraslow dissociation kinetics of host–guest complexation ascertains the stability of supramolecular polymeric coating under the complex physiological condition of blood serum. The coating serves as the gatekeeper for nanovalve with zero premature release and the substrate for surface modification with polyethylene glycol or fluorescent dye via host–guest interaction. Under redox stimuli (glutathione), the nanovalve is opened to release the cargo (doxorubicin). The release rate is tunable depending on coating thickness. Polymer coated MSNs are used for the encapsulation and controlled release of doxorubicin in vitro.