Recent developments of magnetic nanoparticles for theranostics of brain tumor

Background: Glioblastoma multiforme, one of the most aggressive brain tumors, has a very poor clinical outcome. Despite the introduction of the alkylating reagent temozolomide (TMZ) to surgery and radiotherapy, the survival of patients could only be modestly increased up to less than 15 months. Therefore, innovative treatment strategies are urgently needed to improve survival of glioma patients. Objective: Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted a lot of attention due to their widespread diagnostic and therapeutic applications in neuro-oncology. In this review article we discuss the possible application of the SPIONs for the diagnostic and theraputic approaches in brain cancer. Additionally we report on recent pre-clinical and clinical developments on the generation of heat in the tumors through the application of SPIONs subjected to an alternating magnetic field (AMF). Methods: A comprehensive review of the literature on the current status of using targeted SPIONs in brain tumor detection and therapy and also the potential hurdles to overcome was performed. Results: Functionalized nanoparticles carrying tumor-specific agents, such as antibodies or proteins might further improve their tumor targeting capacity. Furthermore, multifunctional, theranostic SPIONs can be used for simultaneous in vivo tumor imaging and targeted drug deliery. Application of the ultrasound and external magnetic field technologies significantly improves accumulation of nanoparticles in brain tumors. Hyperthermic treatment using AMF has a therapeutic potential in management of brain tumors. Conclusion: Superparamagnetic nanoparticle-based imaging, drug delivery and hyperthermic treatment can potentially be a powerful tool for precise diagnosis and treatment of brain tumors.