New Types of Magnetic Nanoparticles for Stimuli-Responsive Theranostic Nanoplatforms

Magnetic nanomaterials have played a crucial role in promoting the application of nanotechnology in the biomedical field. Although conventional magnetic nanomaterials such as iron oxide nanoparticles (NPs) are used as biosensors, drug delivery vehicles, diagnostic and treatment agents for several diseases, the persistent pursuit of high-performance technologies has prompted researchers to continuously develop new types of magnetic nanomaterials such as iron carbide NPs. Considering their potential application in biomedicine, magnetic NPs responsive to exogenous or endogenous stimuli are developed, thereby enhancing their applicability in more complex versatile scenarios. In this review, the synthesis and surface modification of magnetic NPs are focused, particularly iron carbide NPs. Subsequently, exogenous and endogenous stimuli-responsive magnetic NP-based theranostic platforms are introduced, particularly focusing on nanozyme-based technologies and magnetic NP-mediated immunotherapy, which are emerging stimuli-responsive treatments. Finally, the challenges and perspectives of magnetic NPs to accelerate future research in this field are discussed.