NANOCARRIER-BASED DELIVERY OF 5-FLUOROURACIL IN BREAST CANCER: TARGETING TUMOR MICROENVIRONMENT AND OVERCOMING CHEMORESISTANCE
Despite improvements in screening and treatment, breast cancer is still one of the most common cancers diagnosed in women globally and a major cause of cancer-related death. Although 5-fluorouracil (5-FU), a pyrimidine derivative, has long been used in systemic treatments for breast cancer, its low oral bioavailability, dose-limiting toxicities, and acquired resistance restrict its clinical efficacy. By enhancing drug stability, permitting controlled and stimuli-responsive release, and facilitating both passive and active tumor targeting, nanocarrier-based delivery platforms such as lipid-based systems, polymeric nanoparticles, dendrimers, nanogels, inorganic nanostructures, and hybrid nanoplatforms offer promising ways to get around these restrictions. This review synthesizes recent high-impact literature on nanocarrier-mediated delivery of 5-FU for breast cancer, covering pharmacological considerations, nanocarrier classes, targeted and co-delivery approaches, stimuli-responsive designs, challenges to clinical translation, and emerging trends such as personalized nanomedicine and AI-guided carrier optimization.