Multifunctional Magnetic Mesoporous Silica Nanoagents for Enzyme-Responsive Drug Delivery and MR Imaging.

In this study, we report novel multifunctional nanoagents for in vivo enzyme-responsive anticancer drug delivery and magnetic resonance imaging (MRI), based on mesoporous silica coated iron oxide nanoparticles (FeO@MSNs). The anticancer drug, DOX, was encapsulated in the porous cavities with a MMP-2 enzyme responsive peptide being covalently linked to the nanoparticles surface. The in vitro experiment results indicated that the enzyme responsive nanoagents own high specificity for controlled drug release in the cell line with high MMP-2 expression. Furthermore, the targeted delivery of the nanoagents to the tumor site purpose has been successfully achieved through magnet-guided nanocarrier accumulation by utilizing the magnetic properties of the FeO nanocores, which resulted in efficient inhibition of the tumor growth. Additionally, these novel nanoagents can also be used as MRI agent for the real-time diagnosis the tumor treatment process of living animals. Taking the advantages of high specificity, controllable drug release and real-time MRI imaging, we believe these multifunctional nanoagents could also be used as a general platform for the design of stimulus-responsive multifunctional nanomaterials for the aim of accurate diagnosis and efficient treatment of other diseases.