Doxorubicin-Loaded Cerium Oxide Nanoparticles Suppress Cell Proliferation, Migration and Invasion of Triple-Negative...

Cerium oxide nanoparticles (Ceria NPs), possessing redox activity, exhibit selective anticancer effects and hold significant promise for cancer therapy. In this study, Ceria NPs were synthesized via a hydrothermal method and characterized for stability in a biological environment. Optimal colloidal dispersion was achieved in 10% fetal bovine serum (FBS) with a hydrodynamic diameter of 56.3 nm. Ceria NPs exhibited strong antioxidant activity tested by DPPH assay and showed high biocompatibility, displaying minimal toxicity toward normal breast epithelial cells (MCF-10A) while exerting cytotoxic effects on breast cancer cells (IC₅₀ = 363.0 ± 71.89 μg mL^-1 for MCF-7 and 547.9 ± 0.14 μg mL^-1 for MDA-MB-231). Given their limited standalone cytotoxicity but favorable selectivity, Ceria NPs were employed as a nanocarrier for doxorubicin (Dox) to enhance anticancer efficacy while potentially reducing systemic side effects. Ceria-Dox markedly enhanced cytotoxic efficacy, reducing IC₅₀ values to 129.3 ± 21.86 μg mL^-1 in MCF-7 and 33.2 ± 1.37 μg mL^-1 in MDA-MB-231 cells, with more pronounced effects in TNBC cells while maintaining low toxicity toward normal cells. Live/dead staining confirmed a dose-dependent cytotoxicity, while the transwell assay demonstrated strong inhibition of migration and invasion in TNBC cells treated with Ceria-Dox. These findings highlight Ceria-Dox as a colloidally stable nanoplatform that delivers dual therapeutic actions, including potent cytotoxicity and suppression of metastatic potential, underscoring its promise for treating breast cancer, particularly aggressive subtypes such as triple-negative breast cancer.