Bio-magnetic nanomedicine for targeted drug delivery of breast cancer: green synthesis, functional design, and translational challenges.

Breast cancer is an increasing cause of morbidity and death globally. The conventional chemotherapy and ligand-based nanocarriers approaches are facing challenges due to treatment resistance, tumor heterogeneity, and off-target toxicity. In this context, bio-magnetic nanomedicine has emerged as a revolutionary approach, utilizing magnetic nanoparticles for precise drug delivery that goes beyond passive enhanced permeability and retention (EPR) processes. This review investigates the relationship of green synthesis, functional design, and translational issues in the development of bio-magnetic nanocarriers for breast cancer treatment. First conceptual progression of iron oxide contrast agents to field-guided treatment systems are discussed, with a focus on anatomical and microenvironmental limitations specific to breast cancers. Eco-friendly nanoparticle manufacturing, including approaches supported by microbes and plants, receives attention because it improves biocompatibility, lowers oxidative cytotoxicity, and modifies magnetic and theranostic performance. Chemotherapy, hyperthermia, and immunotherapy are among the multimodal therapeutic applications made possible by advanced core-shell designs, tumor-specific surface functionalization, and magneto-responsive drug release techniques, such as AND-gate activation. This review highlights the nano-bio-magnetic interaction, imaging-guided theranostics, and biosafety issues related to iron homeostasis, ferroptosis, and the relative importance of green-synthesized approaches. Finally, translational and clinical challenges such as magnetic field penetration, large scale manufacturing, regulatory pathways, and emerging trends are discussed. In these trends magnetically guided nanorobots, exosome based delivery, and personalized patient-derived tumor models are critically examined. Collectively, this review highlights bio-magnetic nanomedicine as a precision navigation platform, integrating functional design, eco-sustainability, and clinical foresight to advance breast cancer therapy.