A novel encapsulation approach to enhance the delivery and antitumor activity of docetaxel in breast cancer therapy

Docetaxel (DTX) is one of the most potent anticancer drugs but its extensive side effects necessitate innovative formulations. In this study, we aimed to investigate the expression pattern of apoptotic proteins, cell cycle arrest, and apoptosis induction after treatment with encapsulated DTX in alginate-chitosan nanoparticles in both breast cancer cells (MCF-7) and peripheral blood mononuclear cells (PBMCs). The characterization of the nanoparticles revealed a spherical shape with a size <50 nm, a hydrodynamic diameter of 200 nm, a Polydispersity Index of 0.5, and an encapsulation efficiency of 98.75 %. The free drug was released completely within 11 h while encapsulated DTX was released only 34 % in 96 h. The encapsulated drug indicated higher cytotoxicity on MCF-7 cells and the half inhibitory concentration (IC₅₀) value was 2 µg/ml after 72 h. Quantitative real-time PCR demonstrated a significant increase in cell death as the expression of apoptosis regulatory protein (Bcl-2) was downregulated with no impact on Bax in the MCF-7 cells. A notable decrease in the expression pattern of pro-inflammatory cytokine (IL-1β) in PBMCs indicated less inflammation induction. Flow cytometry analysis revealed that the newly formulated drug induced less opoptosis in PBMCs than the free DTX. Cell cycle arrest in the sub-G₁ phase was observed for the free drug while the encapsulated drug exhibited no significant changes. Our results suggest the high toxicity of the formulated drug in contrast to the free DTX on the MCF-7 cell line, minimal blood cell side effects, and no inflammation positioning it as a promising alternative to free docetaxel.