Fabrication of Hybrid Nanostructures Based on Fe 3O 4 Nanoclusters as Theranostic Agents for Magnetic Resonance Imaging and Drug Delivery

摘要

Combining anticancer drugs with inorganic nanocrystals to construct multifunctional hybrid nanostructures has become a powerful tool for cancer treatment and tumor suppression. However, it remains a critical challenge to synthesize compact, multifunctional nanostructures with improved functionality and reproducibility. In this study, we report the fabrication of magnetite hybrid nanostructures employing Fe~(3)O~(4)nanoparticles (NPs) to form multifunctional magnetite nanoclusters (NCs) by combining an oil-in-water microemulsion assembly and a layer-by-layer (LBL) method. The Fe~(3)O~(4)NCs were firstly prepared via a microemulsion self-assembly technique. Then, polyelectrolyte layers composed of poly(allylamine hydrochloride) (PAH) and poly(sodium 4-styrenesulfonate) (PSS) and doxorubicin hydrochloride (DOX) were capped on Fe~(3)O~(4)NCs to construct the Fe~(3)O~(4)NC/PAH/PSS/DOX hybrid nanostructures via LBL method. The as-prepared hybrid nanostructures loaded with DOX demonstrated the pH-responsive drug release and higher cytotoxicity towards human lung cancer (A549) cells in vitro and can serve as T ~(2)-weighted magnetic resonance imaging (MRI) contrast agents, which can significantly improve T ~(2)relaxivity and lead to a better cellular MRI contrast effect. The loaded DOX emitting red signals under excitation with 490?nm are suitable for bioimaging applications. This work provides a novel strategy to build a Fe~(3)O~(4)-based multifunctional theranostic nanoplatform with T ~(2)-weighted MRI, fluorescence imaging, and drug delivery.