Multifunctional porous silica nanoparticles for dual responsive drug release

Porous silica nanoparticles (PSNs) were prepared by hydrolysis of tetraethyl orthosilicate and 3-aminopropyltriethoxysilane in emulsion. The PSN carriers with hierarchical pores are suitable for loading drug and controlling release. Chitosan molecules were used to close all drug-loaded pores to reduce the premature release. Hyaluronic acid (HA) modified carbon dots (CDHA) are further used to encapsulate carriers, which endow them enzyme responsiveness. The PSN carriers display pH/enzyme-responsive release and the drug release follows the first-order kinetics model. CDHA can be used not only for fluorescent marker for carriers, but also for qualitative monitoring of the drug release.