Recent progress and current status of surface engineered magnetic nanostructures in cancer theranostics.

Cancer theranostic is the combination of diagnosis and therapeutic modalities for cancer treatment. It realizes a more flexible, precise and non-invasive treatment of patients. In this aspect, magnetic nanostructures (MNSs) have gained paramount importance and revolutionized the cancer management due to their unique physicochemical properties and inherent magnetic characteristics. MNSs have amazing theranostic ability starting from drug delivery to magnetic hyperthermia and magnetic resonance imaging to multimodal imaging in association with radioisotopes or fluorescent probes. Precise regulation over the synthetic process and their consequent surface functionalization makes them even more fascinating. The ultimate goal is to develop a platform that combines multiple diagnostic and therapeutic functionalities based on MNSs. This perspective has provided an overview of the state-of-art of theranostic applications of MNSs. Special emphasis has been dedicated towards the importance of synthetic approaches of MNSs as well as their subsequent surface engineering and integration with biological/therapeutic molecules that decide the final outcomes of the efficacy of MNSs in theranostic applications. Moreover, the recent advancements, opportunities and allied challenges towards clinical applications of MNSs in cancer management have been demonstrated.