Physical Properties of Mesoporous Silica Nanoparticles for Stimuli-Responsive Drug Delivery.

摘要

The on-demand drug release of mesoporous silica nanoparticles is investigated by chemical modifications of nanomachines and by spectroscopic examination of their physical properties. To improve and diversify their biological performances, acid responsive nanovalve release systems are integrated with gadolinium MRI contrast agents and polyethylene imine-polyethylene glycol surface coatings. Nanoparticles, and bulk media for comparison, are heated superparamagnetically and their temperatures are monitored using the luminescence spectra of lanthanide upconversion nanocrystals. This thermometry technique is applied again in azobenzene nanoimpeller particles to analyze the photothermal and photochemical contributions of IR radiation in initiating cargo release. The emission spectra prove capable of revealing the nanoscale temperature change and the macroscopic dye release simultaneously. Mesoporous silica nanoparticles demonstrate versatile nanomedical delivery capabilities in vitro and in vivo..