Improved Anti-Triple Negative Breast Cancer Effects of Docetaxel by RGD-Modified Lipid-Core Micelles

Purpose: A novel RGD-modified PEGylated lipid-core micelle delivery system was designed to improve the anti-cancer effect of docetaxel on triple negative breast cancer (TNBC). Methods: The tumor-targeted lipid-core micelles loaded with docetaxel were prepared and characterized. Their morphology, particle size, zeta potential, entrapment efficiency, release profiles, and targeting effects were studied. The antitumor effects of the docetaxel-loaded nano-micelles were investigated in a MDA-MB-231 cell model in vitro and a MDA-MB-231 xenograft model in vivo. Results: The prepared RGD-modified docetaxel-loaded lipid-core micelles were spherical with a particle size of 16.44 +/- 1.35 nm, zeta potential of -19.24 +/- 1.24 mV, and an encapsulation efficiency of 96.52 +/- 0.43%. The drug delivery system showed sustained release properties and could significantly enhance docetaxel uptake by MDA-MB-231 tumor cells in vitro, which was proved to be a caveolae pathway mediated process requiring ATP, Golgi apparatus, and acid lysosomes. The results of the pharmacokinetic study displayed that the area under the curve of the targeted micelles was 3.2-times higher than that of docetaxel commercial injections. Furthermore, in a MDA-MB-231 tumor-bearing mice model, a higher antitumor efficacy than docetaxel commercial injections was displayed, and the safety experiments showed that the micellar material did not cause major organ damage after intravenous administration in mice. Conclusion: The novel RGD-modified PEGylated lipid-core micelle delivery system significantly improved the antitumor effects and reduced the side-effects of docetaxel, providing a promising therapeutics for the treatment of TNBC.