Background: Cancer of breast is one of the most popular causes of cancer- related mortality in women. It is a famous condition between women in Saudi arabia, with 21.8% incidence It is rated the second women cancer and its rate is expected to increaseto increase over the next few years.

Aim of the Work: focusing on increase the bioavailability of Chia seeds (Chs) and increase its efficiency against breast cancer using nano delivery system.
Materials and Methods: Preparation of Chia seeds PLGA-PEG nanoparticles and characterize with Transmission Electron Microscope (TEM), Entrapment efficiency measurement and Particle size distribution with zeta potential analyses. Assessing the anti-breast cancer activity using MTT assay and flow cytometry in addition, the Chs nanoparticles against cell migration using wound healing assay.
Results: The TEM image shows spherical NPs with a nano-capsule of PLGA and PEG with Z-average diameters was 62.6 nm. The polydispersity index (PDI) was 0.1 which reflects the high stability of the NPs. Negative charge (zeta potential) showed a consistent pattern on the surface of Chs-loaded PLGA-PEG NPs (ZP= -11.9 mV). Chs NPs exert high cytotoxic effect than Chs. Moreover, the Chs NPs inhibit the cell migration in MCF7 cells. More interestingly that Chs exert apoptosis in breast cancer cells comparing with normal skin fibroblast cells.
Conclusion: The present pilot study showed that Chs NPs has anti-Cancer activity and highlight its role as complementary therapy.