The positive response of superparamagnetic iron oxide nanoparticles (SPIONs), in terms of biodegradability, circulation, elimination, toxicity, and manipulation of their structure/activity relationship, has enabled them to find their way into commercialization as an iron supplement, MRI contrast agents, MPI tracers, and hyperthermia and magneto-mechanical actuators. This Review focuses on the most current progress regarding the application of SPIONs as magnetic therapeutic agents for cancer treatment and tissue engineering. Because of their superior magnetic anisotropy, irreversibility of high- and low-field magnetization, and superparamagnetic ordering at corporal temperatures, they exhibit the unique ability to respond to theraputic doses (e.g., in magnetic hyperthermia and targeted drug delivery). This Review discusses the role of SPIONs to enhance chemotherapy and radiotherapy efficiency and specificity and how this enhancement could mitigate some side effects. SPIONs applied as tools for gene delivery, immunotherapy, and tissue engineering are also reviewed in the context of their potential to translational medicine. Lastly, some emerging issues concerning SPION toxicity are summarized and how they are being addressed to achieve success in clinical applications is discussed.
Keywords: cancer nanotechnology; chemotherapy; hyperthermia; iron oxide nanoparticles; magnetic therapy; magneto-mechanical actuation; radiotherapy.