The synergistic anticancer traits of graphene oxide plus doxorubicin against BT474 and MCF7 breast cancer stem cells in vitro

Breast cancer is among leading causes of death due to cancers around the globe. Current therapeutic approaches towards healing of breast cancer have been associated with poor outcomes. Graphene and its derivatives have a two-dimensional flat structure, which is characterized by the ability to carry drugs and modify the surface, low cytotoxicity and high biocompatibility. This study was performed on MCF7 and BT474 human breast cancer cells. Different concentrations of doxorubicin (DOX), graphene oxide (GO) and graphene oxide plus doxorubicin (GO-DOX) were subjected to both cell lines at specified intervals. At the end of the treatments, MTT test was applied to determine the viability of cells and then flow cytometry, colony formation and spheroid tests were implemented for both cell lines treated with DOX, GO and GO-DOX components. We used DLS and TEM to confirm the GO properties. According to the MTT test results, 1 µL of DOX at 10 mg /mL (equivalent to 0.1 mg / mL) caused 50% survival of MCF7 cells at 24 hours. In both cell lines, an increase in apoptosis occurred after incubation with GO and DOX. Although, a rate of mortality of MCF-7 cells was due to necrosis, the BT474 cells death was merely through the apoptosis. Furthermore, the results of colony formation test outlined an enhancing inhibitory effect in the presence of GO-DOX as a comparison to the control. Additionally, spheroids formed following treatment with GO-DOX exhibited a significant decrease compared to their control group; with an increase in the number of spheroids in BT474 cells compared to those in the MCF-7. The decreasing effect of compounds against the migration and cell invasion potential was also observed, being higher in MCF7 than BT474 cells. The effects of cytotoxic GO were observed at higher concentrations.