Enzyme-sensitive nanoparticles, smart TAT and cetuximab conjugated immunoliposomes to overcome multidrug resistance in breast cancer cells.

Due to recent advances in the field of small molecule-based drugs, designing an efficient siRNA delivery system seems essential. Here, modified sets of lipids conjugated with cell-penetrating TAT peptide, MMP2 enzyme-sensitive moiety, and cetuximab antibodies against the EGF receptor were synthesized, purified and verified on HPLC, TLC, SEM, and DLS analyses. Different cellular and molecular experiments were designed to evaluate the transfection efficiency, targeting properties, and functions, including cytotoxicity assay, resensitization assessments, flow cytometry-based uptake assay, BCRP silencing efficiency, real-time PCR, and western blotting. The final targeted liposomes represented an average diameter of 160 nm; zeta-potential and siRNA encapsulation rates were respectively around -28.9 ± 3.16 mV and 88.3 ± 0.9 w/w. The siBCRP carried by the TATCetuximab liposome led to an increase in the tumoricidal effect of mitoxantrone by a reduction in IC value by 4-fold (*** P < 0.001). Flow cytometry results showed that the cellular uptake rate of final immunoliposomes was significantly higher than the naked liposomes (*** P < 0.001). The Targeted siRNA encapsulating liposomes decreased BCRP transcript and protein levels in MCF7-MX cells by 0.24 and 0.2-fold after 48 h, respectively. Due to the silencing results of the BCRP by the encapsulated siRNA and the inhibitory effects of cetuximab on the EGFR, this formulation could widely be utilized as a carrier for tumor-directed gene delivery.