Red-Light-Responsive Supramolecular Valves for Photocontrolled Drug Release from Mesoporous Nanoparticles

Red-light-responsive supramolecular valves constructed by tetra-ortho-methoxy-substituted azobenzene (mAzo) and β-cyclodextrin (β-CD) were used to control drug release from mesoporous silica nanoparticles (MSNs). Doxorubicin (DOX) was used as a model drug and loaded into nanopores of mAzo modified MSNs. β-CD formed supramolecular valves with mAzo by host–guest interaction and closed the nanopores. Red light was able to open the supramolecular valves and induce DOX release even in deep tissue.