Circumventing paclitaxel resistance in breast cancer cells using a nanoemulsion system and determining its efficacy...

One of the best strategies to circumvent drug resistance is the employment of nanocarriers. For the current study, we have employed a nanoemulsion formulation of paclitaxel (PTX) to bypass drug resistance in the MDA-MB-231 cell line and impedance sensing biosensors to determine the exact time that PTX-NE induced apoptosis. Our MTT results demonstrated that PTX treatment could not reduce MDA-MB-231 cell viability to IC₅₀ even after three days. However, the employment of the reagent TPGS (inhibitor of drug resistance) combined with paclitaxel could partially obviate PTX resistance. Next, the nanoemulsion form of PTX (PTX-NE) was fabricated employing the essential oil of the Satureja khuzestanica plant and was characterized using DLS and TEM methods. Our data showed that after 72 hours, PTX-NE at 250 nM concentration could induce a 50% reduction in cell viability. Moreover, annexin/PI and cell cycle analysis confirmed the apoptotic effect of PTX-NE on cancer cells. Lastly, we measured the impedance of MDA-MB-231 cells treated with the free and nanoemulsion forms of PTX. A significant decrease in the mean impedance of PTX-NE treated cells could be observed after 40 hours. To conclude, we have demonstrated here that PTX-NE could circumvent resistance and induce apoptosis in PTX-resistant breast cancer cells, which could be inferred from their impedance measurement.