Applications and Efficacy of Iron Oxide Nanoparticles in the Treatment of Brain Tumors

Abstract

Cancers of the central nervous system are particularly difficult to treat due to a variety of factors. Surgical approaches are impeded by the skull-an issue which is compounded by the severity of possible harm that can result from damage to the parenchymal tissue. As a result, chemotherapeutic agents have been the standard of care for brain tumors. While some drugs can be effective on a case-by-case basis, there remains a critical need to improve the efficacy of chemotherapeutic agents for neurological cancers. Recently, advances in iron oxide nanoparticle research have highlighted how their unique properties could be leveraged to address the shortcomings of conventional therapeutics. Iron oxide nanoparticles combine the advantages of good biocompatibility, magnetic susceptibility, and functionalization via a range of coating techniques. Thus, iron oxide nanoparticles could be used in both the imaging of brain cancers with magnetic resonance imaging, as well as acting as trafficking vehicles across the blood-brain barrier for targeted drug delivery. Moreover, their ability to support minimally invasive therapies such as magnetic hyperthermia makes them particularly appealing for neuro-oncological applications, where precision and safety are paramount. In this review, we will outline the application of iron oxide nanoparticles in various clinical settings including imaging and drug delivery paradigms. Importantly, this review presents a novel approach of combining surface engineering and internal magnetic targeting for deep-seated brain tumors, proposing the surgical implantation of internal magnets as a next-generation strategy to overcome the limitations of external magnetic fields.

Keywords: drug delivery; iron oxide nanoparticles; neurological cancer.

Figure 1

Conceptual overview of IONP synthesis methods (center), their key functional applications (right), and corresponding clinical applications (left). Each synthesis route—co-precipitation, thermal decomposition, hydrothermal synthesis, and microemulsion—can be tailored to produce nanoparticles optimized for imaging, drug delivery, or magnetic hyperthermia. These functionalized IONPs can then be employed to treat superficial and deep-seated tumors, with ongoing research pointing to future directions for further clinical translation.

Figure 2

Conceptual design. Superficial brain tumor, treatable through external magnetization. Initial tumor mass shown in (A). Partial removal of the tumor through surgery, leaving residual cancerous cells due to the tumor’s irregular shape (B). After injecting IONPs, an external magnet is applied to attract nanoparticles to the tumor resection site (C). The localized IONPs then target residual cancer cells and potentially improve patient outcomes (D). Here, we recommend using IONPs synthetized with the co-precipitation method due to the simplicity and scalability of co-precipitation, which enables the rapid production of nanoparticles used in treatments involving external magnetic targeting.

Figure 3

Conceptual design. The proposed treatment for a deep tumor utilizing internal magnetization. Initial tumor mass (A). Partial removal of the tumor during surgery, leaving some residual cancerous tissue (B). Placement of a magnet in the tumor cavity during surgery (C). Following IONP injection, the internal magnet attracts the nanoparticles to the resection site, providing stable and continuous localization. This increases the likelihood of eradicating residual tumor cells and improving patient outcomes. (D) Here, we recommend using IONPs synthetized with thermal decomposition method due to the precision and monodispersity which thermal decomposition provides to optimize nanoparticle localization and retention in deep-seated tumor cavities.