Codelivery of Gemcitabine and MUC1 Inhibitor Using PEG-PCL Nanoparticles for Breast Cancer Therapy

In breast cancer therapy, Gemcitabine (Gem) is an antineoplastic antimetabolite with greater anticancer efficacy and tolerability. However, effectiveness of Gem is limited by its off-target effects. The synergistic potential of MUC1 (mucin 1) inhibitors and Gem-loaded polymeric nanoparticles (NPs) was discussed in this work in order to reduce dose-related toxicities and enhance the therapeutic efficacy. The double emulsion solvent evaporation method was used to prepare poly(ethylene glycol) methyl ether-block-poly-caprolactone (PEG-PCL)-loaded Gem and MUC 1 inhibitor NPs. The average size of Gem and MUC 1 inhibitor-loaded NPs was 128 nm, with a spherical shape. Twin-loaded NPs containing Gem and the MUC1 inhibitor decreased IC₅₀ and behaved synergistically. Furthermore, in vitro mechanistic studies, that is, loss of MMP, clonogenic assay, Annexin V FITC assay, and Western blotting to confirm apoptosis with simultaneous induction of autophagy using acridine orange (AO) staining were performed in this study. Furthermore, the investigated NPs upon combination exhibited greater loss of MMP and decreased clonogenic potential with simultaneous induction of autophagy in MCF-7 cells. Annexin V FITC clearly showed the percentage of apoptosis while Western blotting protein expression analysis revealed an increase in caspase-3 activity with simultaneous decrease in Bcl-2 protein expression, a hallmark of apoptosis. The effectiveness of the Ehrlich ascites solid (EAT) mice treated with Gem-MUC1 inhibitor NPs was higher than that of the animals treated alone. Overall, the combined administration of Gem and MUC1 inhibitor-loaded NPs was found to be more efficacious than Gem and MUC1 inhibitor delivered separately.