Advances in nano-drug delivery systems for targeting therapy of breast cancer

BACKGROUND: Breast cancer is the most common malignant tumor among women worldwide, and conventional chemotherapy faces major challenges including poor targeting, severe systemic toxicity, and drug resistance. OBJECTIVE: This review analyzes the application of nano-drug delivery systems (NDDS) in improving breast cancer chemotherapy, with a particular focus on recent advances in nanocarrier-based targeting strategies. METHODS: This review systematically outlines the current epidemiology and clinical treatment landscape of breast cancer, and provides a detailed analysis of various drug delivery systems (e.g., liposomes, polymeric micelles, inorganic nanoparticles) and their targeting mechanisms, including passive, active, and physicochemical-responsive targeting. RESULTS: NDDS enhance tumor-selective uptake and therapeutic efficacy while reducing side effects, especially active-targeting systems modified with small-molecule ligands such as biotin. Furthermore, NDDS can circumvent multidrug resistance by inhibiting efflux pumps and modulating the tumor microenvironment. CONCLUSION: Nano-drug delivery systems represent a promising disease-modifying approach for precise breast cancer treatment, though challenges remain in clinical translation, which may be overcome through interdisciplinary collaboration and systematic optimization.