Next-generation superparamagnetic iron oxide nanoparticles for cancer theranostics

Superparamagnetic iron oxide (SPIO) nanoparticles have been intensively studied for the development of contrast agents in MRI. First-generation SPIO nanoparticles had diagnostic capabilities only, whereas a new generation of SPIO nanoparticle has multifunctional characteristics for combined therapeutic and diagnostic applications. These theranostic nanoparticles hold great potential for image-guided cancer therapies. In particular, polymer-coated theranostic SPIO nanoparticles have enjoyed increasing attention as a result of good biocompatibility, biodegradability and versatile functionality endowed by polymeric matrices. This review provides an overview of recently developed polymer-coated multifunctional SPIO nanoparticles for cancer theranostics and discusses current challenges and future perspectives.