Shen and Chen group from Wenzhou Medical University have summarized functional magnetic iron oxide nanoparticles (Fe3O4 NPs) have shown great potential as an advanced platform because of their inherent magnetic resonance imaging (MRI), biocatalytic activity (nanozyme), magnetic hyperthermia treatment (MHT), photo-responsive therapy and drug delivery for chemotherapy and gene therapy.
 
Magnetic Fe₃O₄ NPs can be synthesized through several methods and easily surface modified with biocompatible materials or active targeting moieties. The MRI capacity could be appropriately modulated to induce response between T₁ and T₂ modes by controlling the size distribution of Fe₃O₄ NPs. Besides, small-size nanoparticles are also desired due to the enhanced permeation and retention (EPR) effect, thus the imaging and therapeutic efficiency of Fe₃O₄ NP-based platforms can be further improved. Here, we firstly retrospect the typical synthesis and surface modification methods of magnetic Fe₃O₄ NPs. Then, the latest biomedical application including responsive MRI, multimodal imaging, nanozyme, MHT, photo-responsive therapy and drug delivery, the mechanism of corresponding treatments and cooperation therapeutics of multifunctional Fe₃O₄ NPs are also be explained. Finally, we also outline a brief discussion and perspective on the possibility of further clinical translations of these multifunctional nanomaterials. This review would provide a comprehensive reference for readers to understand the multifunctional Fe₃O₄ NPs in cancer diagnosis and treatment. This work was published in the Theranostics (IF：8.036)
 
This work was financially supported by the National Natural Science Foundation of China (31800833 and 21977081), Zhejiang Provincial Natural Science of Foundation of China (Z19H180001), the Wenzhou Medical University and Wenzhou Institute of Biomaterials & Engineering (WIBEZD2017001-03).