Co-delivery of curcumin and Bcl-2 siRNA to enhance therapeutic effect against breast cancer cells using PEI-functionalized PLGA nanoparticles

Purpose: Breast cancer is the second major cause of death worldwide among women. Co-delivery of anticancer drugs and nucleic acids targeting the apoptosis pathway could be a promising new approach. Methods: In the present study, we synthesized a novel nanostructure for the co-delivery of curcumin and siRNA to breast cancer cells. Curcumin-loaded polylactic-co-glycolic acid (PLGA) was synthesized using an O/W emulsion-solvent diffusion method. It was coated with polyethylenimine (PEI) and subsequently complexed with Bcl-2 siRNA. Also, nanoparticles were characterized such as zeta potential, size distribution and drug encapsulation. Finally, the cytotoxicity of NP and Bcl-2 expression was evaluated. Results: The curcumin-loaded PLGA nanoparticles were 70 nm in size, and increased to 84 nm after incorporation of PEI plus Bcl-2 siRNA. The encapsulation ratio of the drug in our nanoparticle was 78%. Cellular internalization of PLGA-CUR-PEI/Bcl-2 siRNA NPs was confirmed by fluorescence microscopy with the broadcasting of the fluorescence in the cytoplasm and into the nucleus. The results of the cell viability assay revealed that curcumin-loaded PLGA coated with PEI and Bcl-2 siRNA exhibited the highest cytotoxicity against the T47D cell line, while the siRNA decreased the Bcl-2 expression by 90.7%. Conclusion: The co-delivery of curcumin plus Bcl-2 siRNA with the PLGA-PEI nanosystem could be a synergistic drug carrier against breast cancer cells.