Enhanced cytotoxic efficacy against MCF-7 and HCT116 cell lines and high-performance cefoperazone removal using biogenically synthesized CeO2 nanoparticles

Abstract

The biosynthesis of cerium oxide nanoparticles “CeO2 NPs” using an aqueous Echinacea purpurea leaf extract (EP) was conducted. EP extract is a great source of organic compounds, such as polyphenols and flavonoids, with high antioxidant activity, providing a high degree of stabilizing and capping for the formed CeO2 NPs. Physicochemical and related morphological properties of the as-biosynthesized CeO2 NPs were explored using diverse analytical techniques. Results showed that the as-prepared CeO2 NPs were crystalline pure spherical with a cubic system, with an average crystallite size of 10.8nm as determined by XRD, and an average particle size of 12.3 nm as determined via TEM. A large surface area of 100.3 m²/g with a monodispersed phase with a crystallinity index of 1.2 was achieved. Moderate stability with Zeta potential of -27.8 ± 0.20 mV and PDI 0.126 ± 0.031 were illustrated. The cytotoxicity of the as-biosynthesized CeO2 NPs against two types of cell lines, MCF7 and HCT116 was studied, showing promising impacts where the IC50 values for MCF7 and HCT116 were found to be 78.5 and 128.8 µg/mL, respectively. Additionally, the adsorption technique of the as-prepared CeO2 NPs was studied for the removal of cefoperazone. The study demonstrated that the adsorption followed the Langmuir isothermal model with a maximum loading capacity of 201.4 mg/g and a pseudo-second-order kinetic model. Therefore, the as-biosynthesized CeO2 NPs have promising potential as an anticancer agent and for pharmaceutical wastewater remediation. Also, Cefo@CeO2 NPs were carefully prepared after the determination of the optimum adsorption conditions. Antibacterial activity for both the as-prepared CeO2 NPs and Cefo@CeO2 NPs against gram-positive (S. aureus and B. subtilis) and gram-negative (P. aeruginosa, B. cepacia, E. coli, and S. typhimurium) bacteria was conducted. Cefo@CeO2 NPs exhibited a dose-dependent response, with significant synergistic effects reaching 76 % and 82 %-fold increase for P. aeruginosa and B. cepacia respectively, indicating promising potential for combating bacterial infections.