Investigating the therapeutic effect of folic acid conjugated ZnO nanoparticles on human triple negative breast cancer cell line

Triple-negative breast cancer (TNBC) accounts for 15-20% of all invasive breast cancers and has a poor prognosis. ZnO NPs are promising anti-cancer agents. Moreover, folate Alpha receptor (FRa) is a potential biomarker and therapeutic target because it is significantly expressed in TNBC. Therefore, ZnO and folic acid-conjugated ZnO (F-ZnO) NPs were synthesized by the solgel method. NPs were characterized by DLS, zeta potential, TEM, FTIR, and ICP-MS. FA-ZnO NPs had a mean diameter of 20 ± 2 nm and a surface charge of -15 mV, while ZnO NPs had a mean diameter of 40 ± 5 nm and a surface charge of -5 mV. The MTT assay and trypan blue test, respectively, were used to determine the cytotoxicity and viability percentage of ZnO and F-ZnO NPs at different concentrations of 2, 4, 8, 16, 32, 64 and 128 µg/mL for 12, 24, 48 and 72 hours (h) on the human TNBC cell line MDA-MB-231. The results indicated that both ZnO and F-ZnO NPs significantly reduced the viability of the cancer cells in a dose-dependent and time-dependent manner (p<0.05). The IC50 values for FA-ZnO NPs were approximately 3, 3.74, 4.38 and 5.5 times higher than those for ZnO NPs at 12-, 24-, 48and 72-hour time points, respectively. The results suggest that F-ZnO NPs have the potential to be a good option for TNBC treatment and warrant further investigations.