DNA-Hybrid-Gated Multifunctional Mesoporous Silica Nanocarriers for Dual-Targeted and MicroRNA-Responsive Controlled Drug Delivery**

The design of an ideal drug delivery system with targeted recognition and zero premature release, especially controlled and specific release that is triggered by an exclusive endogenous stimulus, is a great challenge. A traceable and aptamer-targeted drug nanocarrier has now been developed; the nanocarrier was obtained by capping mesoporous silica-coated quantum dots with a programmable DNA hybrid, and the drug release was controlled by microRNA. Once the nanocarriers had been delivered into HeLa cells by aptamer-mediated recognition and endocytosis, the overexpressed endogenous miR-21 served as an exclusive key to unlock the nanocarriers by competitive hybridization with the DNA hybrid, which led to a sustained lethality of the HeLa cells. If microRNA that is exclusively expressed in specific pathological cell was screened, a combination of chemotherapy and gene therapy should pave the way for a targeted and personalized treatment of human diseases.