Controlled drug delivery from mesoporous silica using a pH-response release system

Mesoporous hollow silica nanoparticles were functionalized with phenanthroline (P-MHS) to prepare a carrier for a host–guest complex. Curcumin was selected as a model drug molecule. The phenanthroline attached to the P-MHS was complexed with Cu2+ through a coordination bond. When the Cu2+–P-MHS was exposed to ∼pH 5, the curcumin was efficiently released into the aqueous phase within 120 min. This work describes a method for functionalizing the surface of the porous silica nanoparticles in a well-defined manner. The P-MHS carrier exhibited controlled release of a model drug under acidic pH conditions.