Multifunctional poly(d,l-lactide-co-glycolide)/montmorillonite (PLGA/MMT) nanoparticles decorated by Trastuzumab for targeted chemotherapy of breast cancer

This paper continued our earlier work on the poly(d,l-lactide-co-glycolide)/montmorillonite nanoparticles (PLGA/MMT NPs), which were further decorated by human epidermal growth factor receptor-2 (HER2) antibody Trastuzumab for targeted breast cancer chemotherapy with paclitaxel as a model anticancer drug. Such a NP system is multifunctional, which formulates anticancer drugs with no harmful adjuvant, reduces the side effects of the formulated anticancer drug, promotes synergistic therapeutic effects, and achieves targeted delivery of the therapy. The paclitaxel-loaded PLGA/MMT NPs were prepared by a modified solvent extraction/evaporation technique, which were then decorated with Trastuzumab. The effects of the surface decoration on particle size and size distribution, surface morphology, drug encapsulation efficiency, as well as the drug release kinetics, were investigated. The NP formulation exhibited a biphasic drug release with a moderate initial burst followed by a sustained release profile. The surface decoration speeded the drug release. Surface chemistry analysis was conducted by X-ray photoelectron spectroscopy (XPS), which confirmed the presence of Trastuzumab on the NP surface. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed the stability of the antibody in the NP preparation process. Internalization of the coumarin-6-loaded PLGA/MMT NPs with or without the antibody decoration by both of Caco-2 colon adeno carcinoma cells and SK-BR-3 breast cancer cells was visualized by confocal laser scanning microscopy and quantitatively analyzed, which shows that the antibody decoration achieved significantly higher cellular uptake of the NPs. The results of in vitro cytotoxicity experiment on SK-BR-3 cells further proved the targeting effects of the antibody decoration. Judged by IC50 after 24 h culture, the therapeutic effects of the drug formulated in the NPs with surface decoration could be 12.74 times higher than that of the bare NPs and 13.11 times higher than Taxol®.