OBJECTIVE:To focus a new chemoprevention approach that uses nanotechnology to deliver luteolin to human breast cancer cells (MCF-7),and its underlying mechanism.METHODS:Water-soluble copolymer-encapsulated nanoparticle-luteolin (CENL) was formulated using the hydrophobic drug luteolin.The ability to load and release he anticancer drug into/from the synthesized hyperbranched polyester was evaluated by high-performance liquid chromatography.The successful synthesis of CENL was supported by analytical techniques including fourier transform infrared spectroscopy,nuclear magnetic resonance spectroscopy,gel permeation chromatography,and dynamic light scattering.Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide color method.Reactive oxygen species (ROS) were measured using a dichlorofluorescein probe and intracellular calcium (Cai2+) was evaluated with a flu3-AM probe.RESULTS:The results showed that the drug delivery system is stable and that the loading capacity is high.Treatment with nanoparticles containing luteolin and free luteolin resulted in cell death in breast cancer cells at high concentrations [IC50 (33 + 4) and (48 + 6) μM,respectively].At high concentrations,CENL reduced cell viability and increased ROS and Cai2+ production.CONCLUSION:Our results demonstrate that CENL has potential for human breast cancer treatment.