Preparation of multifunctional Fe3O4@ZnAl2O4:Eu3+@mSiO2–APTES drug-carrier for microwave controlled release of anticancer drugs

Abstract

A carrier possessing simple structure and composition, but with microwave-targeted-fluorescence multifunctional properties to precisely control the delivery of the drug was prepared. Herein, we have constructed the multifunctional Fe₃O₄@ZnAl₂O₄:Eu³⁺@mSiO₂–APTES core–shell drug-carrier via direct precipitation method and sol–gel process with surfactant-assistance approach. This carrier is a monodisperse microsphere with an average particle size of 325 nm. Fe₃O₄ in the core has a high saturation magnetization and provides the Fe₃O₄@ZnAl₂O₄:Eu³⁺@mSiO₂–APTES with good drug targeting properties. The ZnAl₂O₄:Eu³⁺ interlayer has the characteristic of fluorescent luminescence and can be used to monitor the transport of drugs in the body in real time. In addition, the ZnAl₂O₄:Eu³⁺ as a dielectric loss microwave absorbing material combines with the high magnetic loss Fe₃O₄ to form a composite material, which improved the microwave thermal response. Over 78.2% of VP16 molecules were released under microwave trigger. In addition, mesoporous silica nanoparticles in the outer layer improve the drug loading efficiency through organic modification. The results indicated that this multifunctional drug-carrier with simple structure and composition is a potential controlled drug delivery system in cancer therapy.