Molecular-nanotechnology for signal-stimulated drug release control

Functional molecules can perform various operations when they are appropriately reorganized with nanostructures. Here we would like to communicate our recent progress in controlled release system based on molecule functionalized nanomaterials. A multifunctional, fully controlled storage and release system was assembled by installing two photomechanical units that behave as ¿stirrer¿ and ¿gate¿ functions into mesoporous silica. Drugs are released when the gate is closed. An enhancement of the release rate of the guest molecule in mesoporous silica is induced by reversible photoisomerization of azobenzene groups attached to the inner surface when the gate is open. Such controlled release systems can delivery drugs into cancer cells and release drugs under light irradiation.