Iron Carbide Nanostructures: An Emerging Material for Tumor Theranostics

Abstract

ConspectusIron carbide (IC) nanostructures have attracted intense interest in several energetic and magnetic-related fields due to their high saturation magnetization, desirable stability, and excellent catalytic activity. Due to their iron-based magnetic capacity and carbon-arising near-infrared light-responsive performance, IC nanostructures have been regarded as emerging materials for tumor theranostics in the past decades. They have been extensively explored in several tumor-related biomedical areas, such as magnetic targeting, magnetic resonance imaging, magnetic hyperthermia, photoacoustic tomography, and photothermal therapy. In view of the growing requirements for tumor theranostics, IC nanostructures need to be incorporated with other nanostructures to form the improved IC-based nanocomposites. The success of such a manufacturing process needs not only the deep understanding of the synthesis mechanism of IC nanostructures but also the functionality of IC nanostructures in tumor diagnosis and therapy, as well as the interaction between IC nanostructures and the specific tumor microenvironment. By forming IC-based nanocomposites, the application scope of IC nanostructures is expanded to some unexplored areas, expecting to discover new biological functionality. In this Account, we summarize the synthesis and surface modification of IC-based nanostructures, and their recent promising applications in tumor theranostics, aiming to provide some paradigms for designing IC-based nanocomposites and uncover the interactions between IC-based nanocomposites and biological systems.The great potential of IC nanostructures in tumor theranostics is promoted by understanding their stimuli-responsive behavior in the tumor microenvironment and incorporating them with other functional materials to construct IC-based nanocomposites. For diagnosis purposes, IC nanostructures are excellent contrast agents for magnetic resonance imaging and photoacoustic tomography. Their applications can be expanded to other diagnostic modalities by suitable design of IC-based nanocomposites, such as introducing silver sulfide for fluorescence imaging. For therapy purpose, IC nanostructures can kill tumor cells through magnetic hyperthermia and photothermal effect, as well as using Fenton reaction-generated toxic hydroxyl radical. Furthermore, they can act as targeting carriers for antitumor drugs, releasing the payload on-demand at tumor site for chemotherapy. In the end, we look at the challenges and possible research directions for IC nanostructures, hoping to provide inspiration for future investigation.