pH and GSH dual-responsive fluorescent nanoparticles from polydopamine coating mesoporous silica for controlled drug release and real-time detection

pH and GSH dual-responsive nanoparticles with fluorescence detection were successfully prepared from the polydopamine coating on the surface of mesoporous silica via disulfide bonds (MSN-SS-PDA). The average diameter of nanoparticles was about 80-100 nm with a well-ordered mesoporous structure. The outer layer of PDA was about 10.0 nm acting as a pH and GSH sensitive gatekeeper to control drug release. Doxorubicin (DOX) was loaded into mesoporous channels to evaluate the drug loading capacity and controlled release performance. TPE-4OH, an aggregation-induced emission (AIE) luminescence, was adhered to the surface of PDA for detection of drug release in real-time. The drug release from MSN-SS-PDA nanoparticles was enhanced under acidic solutions or high GSH concentrations. The fluorescence intensity decreased gradually with the drug release, which can be used for monitoring of release process. Besides, the nanoparticles exhibited good photothermal conversion capability due to the PDA layer under near-infrared light irradiation at 808 nm. These nanoparticles present a promising future for combination therapy and real-time tracking of the release process.