PH-responsive drug delivery system based on coordination bonding in a mesostructured surfactant/silica hybrid

pH-responsive drug delivery systems have attracted great interest because of their potential use in antitumor therapies. Herein, we report a facile one-pot fabrication of a "host-metal-drug" coordination-bonding system in a mesostructured surfactant/silica hybrid for the pH-responsive drug delivery purpose. The mesostructure has been synthesized by self-assembly of nontoxic and biocompatible F127 Pluronic nonionic surfactant and silica source through a real liquid crystal templating route, in which F127 act as host molecules. Metal ions such as Zn, Cu, and Fe and drugs have been introduced simultaneously into the mesostructure synthesis systems, to form F127-metal-drug coordination-bonding architecture. The cleavage of the coordination bonds that are sensitive to variations in external pH gives rise to the release of the drug under weakly acidic conditions (pH 5.0-6.0). To assist in the release of drugs without significant binding capabilities, a vector has been designed to endow coordinately inert drugs with pH-responsive properties. Furthermore, the pH responsibility has been confirmed by cell assay and in vivo tumor test, opening up new opportunities for the potential application as implants in antitumor therapies.