Synthesis and characterization of a gluta­thione-responsive drug delivery system based on aptamer-coated mesoporous silica

Chemotherapy drugs, though effective against cancer, often pose challenges due to their high toxicity and adverse effects. To address these issues and prevent premature drug release, a straightforward yet smart gluta­thione (GSH)-responsive drug delivery system (DDS) based on aptamer-coated mesoporous silica has been developed. Mesoporous silica serves as the drug carrier, with the anticancer drug model doxorubicin (Dox) efficiently loaded in, sealed by coating with aptamer AS1411. The characteristics of the resulting microspheres were investigated by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and zeta potential measurements. These analyses confirmed the successful bonding of AS1411 to the surface of the mesoporous silica. Drug-release tests were conducted under two distinct pH conditions (pH 5.0 and 7.4), both in the presence and in the absence of GSH. The results demonstrate the remarkable ability of this DDS to respond to GSH, facilitating controlled drug release. The single coated layer on the particle serves a dual purpose by blocking pore openings and triggering an endogenous stimulus response, ensuring the precise release of pharmaceuticals during drug delivery. This GSH-responsive DDS holds the potential to mitigate drug-induced harm to healthy tissues, offering a new approach for cancer treatment.