Synthesis of Quercetin Functionalized Wurtzite Type Zinc Oxide Nanoparticles and Their Potential to Regulate Intrinsic Apoptosis Signaling Pathway in Human Metastatic Ovarian Cancer

In the present study, the wurtzite (WZ) type of zinc oxide (ZnO) nanoparticles were synthesized and functionalized with quercetin (ZnO@Quercetin) for the treatment of ovarian cancer. Initially, the chemical synthesis of ZnO nanoparticles was confirmed with DRS UV-vis spectroscopy and the bandgap of the ZnO revealed that the WZ type of nanoparticles. The electron microscopy analysis showed the hexagonal shape, monocrystalline nature of nanoparticles with an average size of 20-25 nm and the SAED pattern showed the interplanar planes for WZ type nanoparticles. XRD analysis revealed the presence of strong peaks corresponding to ZnO nanoparticles and the Raman spectroscopic analysis showed the characteristic peaks at E (high) and E1 vibrational mode for WZ type of ZnO nanoparticles. The in vitro cytotoxic activity of ZnO@Quercetin nanoparticles showed the excellent activity by generating intercellular oxidative stress and depolarization of mitochondrial membrane potential against human ovarian cancer cells. The dual-staining assay showed that the ZnO@Quercetin induces late apoptosis through activation of the intrinsic apoptosis signaling pathway in PA-1 cells. Together, the present study indicates the ZnO@Quercetin nanoparticles can be used for the treatment of human metastatic ovarian cancer.