Nanoceria: Polyphenol-based green synthesis, mechanism of formation, and evaluation of their cytotoxicity on L929 and HFFF2 cells

Abstract

The green synthesis of nanomaterials stands as a new strategy in the fields of nanoscience and nanotechnology throughout the past decays. The aim of this study was to perform the green synthesis and characterization of nanoceria (NCs) by the utilization of Tannic acid (TA) as a polyphenolic compound. The NCs have been synthesized via the chemical reduction method, which involved the usage of TA in the role of a green reducing and stabilizer agent. The NCs have been sintered in 400, 500, and 600 °C to obtain NCs in the form of light-yellow fine powders. The prepared NCs have been characterized by the employment of UV–vis, TG/DTG, XRD, FESEM, TEM, and FTIR. The cytotoxicity and oxidative stress of NCs, which had ranged between 6.25 and 800 μg/ml, have been evaluated on L929 and HFFF2 cell lines through the MTT and DCFH-DA assays. Statistical analysis of the data has been performed via One-way ANOVA, while p < 0.05 had been selected as the significance level. The small and uniformed NCs had been observed within the FESEM micrographs. It has been indicated by the XRD results that TA is capable of producing NCs with the size of 7.1, 9.2, and 13.1 nm in 400, 500, and 600 °C, respectively. TEM images of sintered NCs have shown nanoparticles that contained a size of 18 nm. The zeta-potential and polydispersity index (PDI) results have also illustrated the negative surface charge and satisfying heterogeneity of NCs. The NCs have exhibited a proliferation effect in 6.25–200 μg/ml but a decrease in 800 μg/ml. The NCs also showed that are able to reduce intracellular reactive oxidative stress in range of 6.25–800 μg/ml. It can be noted as a conclusion that NCs have displayed antioxidant properties in normal cells and are apparently abled to decrease the intracellular free radicals. This approach is comparable to the conventional methods that involve the usage of hazardous chemicals and reagents for performing the fabrication of NCs.