Iron Oxide Nanoparticles as Magnetic Nanocarriers for Targeted Delivery of Anticancer Biomolecules

The advancement of nanotechnology has revolutionized cancer therapy, with iron oxide (Fe3O4) nanoparticles emerging as a pivotal platform for magnetically targeted drug delivery. This review critically examines the functionalization and biomedical applications of Fe3O4 nanoparticles, focusing on their design, targeting capabilities, and therapeutic potential. Surface engineering strategies—including polymer coatings, silica shells, and ligand conjugation—enhance nanoparticle stability and facilitate functional modifications in biological environments. Magnetic targeting enables precise accumulation at tumor sites under external fields, improving therapeutic efficacy while minimizing off-target toxicity. The conjugation of Fe3O4 nanoparticles with anticancer biomolecules such as chemotherapeutic drugs, small interfering RNA (siRNA), and therapeutic proteins achieves synergistic and site-specific treatment effects. Both in vitro and in vivo studies are evaluated to highlight their efficiency in cellular uptake, biodistribution, and tumor suppression. Safety and biocompatibility are addressed, emphasizing strategies to mitigate adverse effects and potential toxicities. Despite their promise, challenges—including nanoparticle aggregation, immunogenicity, and clinical translation – remain. The review concludes by identifying future directions, including multifunctional platforms, stimuli-responsive release systems, and integration with diagnostic modalities, aimed at advancing Fe3O4-based nanocarriers toward clinical application.