Purpose. Study of the bioprotective properties of ablated cerium dioxide nanoparticles in relation to immortalized human fibroblasts under conditions of oxidative stress caused by the Fenton reaction.Methods. Cerium dioxide nanoparticles with pronounced antioxidant properties were obtained using laser ablation. The average maximum sizes of ablated particles of oxidized cerium in non-centrifuged and centrifuged at a speed of 1000 rpm nanodispersed aqueous solutions were revealed using the method of atomic force microscopy. The spectrophotometric method revealed that ablated cerium dioxide nanoparticles exhibit antioxidant properties and prevent the degradation of the methylene blue dye during the Fenton reaction. Cell culture samples were mapped using scanning electron microscopy using an energy-dispersive attachment after their incubation with ablated cerium dioxide nanoparticles. Using MTT analysis, the effect of ablated cerium dioxide nanoparticles on the survival of BJ TERT cell culture in the Fenton reaction was studied. Non-centrifuged and centrifuged at a speed of 1000 rpm nanodispersed solutions of oxidized cerium were used. The antioxidant activity of cerium dioxide nanoparticles after 6- and 24-hour incubation was studied.Results. The average limiting sizes of ablated cerium dioxide nanoparticles have been established, the values of which are (61,95±0,1) nm for a non-centrifuged aqueous solution and (56,59±0,1) nm for an aqueous solution centrifuged at a microcentrifuge speed of 1000 rpm. It was revealed that in the presence of ablated cerium dioxide nanoparticles, the degree of oxidative degradation of methylene blue during the Fenton reaction was significantly reduced. It was found that with an increase in the concentration of ablated cerium dioxide nanoparticles from 20 to 1000 mg/l, their antioxidant effect increased. From the obtained SEM images of cell cultures with ablated cerium dioxide nanoparticles, it follows that the nanoparticles are captured by cells during incubation and can have a significant effect on oxidative processes during the Fenton reaction. Statistical analysis based on the results of the MTT assay showed that 6-hour and 24-hour incubation with ablated cerium dioxide nanoparticles had a pronounced protective effect on the BJ TERT cell line.Conclusion. This work shows that during the Fenton reaction, cerium dioxide nanoparticles prevent the oxidative degradation of the methylene blue dye. When immortalized human fibroblasts are incubated, ablated cerium oxide nanoparticles are taken up by the cells and have a significant protective effect on them in the oxidative reaction. The high antioxidant activity of nanoparticles is determined by the high content of functional defects on the surface of nanoparticles obtained under sharply nonequilibrium conditions of laser ablation.
