A novel Janus nanomachine based on mesoporous silica nanoparticles anisotropically modified with PAMAM dendrimers for enzyme-controlled drug delivery.

A masking/toposelective modification approach was employed to prepare a new organic-inorganic Janus nanomaterial by attaching ethylenediamine core polyamidoamine G-4.5 dendrimers to a defined face of mesoporous silica nanoparticles. The anisotropic colloid was then sequentially functionalized on the mesoporous face with (3-isocyanatopropyl)triethoxysilane, 1-(4-aminophenyl)-2-phenylethane-1,2-dione and β-cyclodextrin to assemble a novel HO-sensitive gating mechanism.