HER-2 aptamer-targeted Ecoflex® nanoparticles loaded with docetaxel promote breast cancer cells apoptosis and anti-metastatic effect.

Breast cancer is a major cause of cancer mortality. Regarding the advantages of polymeric nanoparticles as drug delivery systems with targeting potential, in this study the antitumor mechanism of targeted docetaxel polymeric nanoparticles of Ecoflex® was exploited. Since the overexpression of HER-2 receptor in breast cancer cases is associated with poor prognosis and more aggressive disease, the proposed nanoparticles were conjugated to HER-2 specific aptamer molecules. In vitro cytotoxicity was evaluated by MTT assay. Flow-cytometry analysis was performed to evaluate the cellular uptake of nanoparticles loaded with a fluorescent probe. Anti-migration effects of samples were studied. Annexin IV-FITC and propidium iodide were implemented to investigate apoptosis induction and cell cycle analysis. Enhanced cytotoxicity compared with free docetaxel was explained considering improved cellular uptake of the nanoparticles and induced apoptosis in a larger portion of cells. Lower relative migration demonstrated enhanced anti-migration effect of nanoparticles, and cell cycle was arrested in G2/M phase using both formulations so the anti-microtubule mechanism of the drug was not altered. Therefore, this system could offer a potential substitute for the currently marketed docetaxel formulations, which may reduce adverse effects of the drug, while further in vivo and clinical investigations are required.