Cerium dioxide nanoparticles modulate the oxidative metabolism of neutrophils upon blood irradiation with a pulsed broadband UV source

The effect of CeO$_2$ nanoparticles on the oxidative activity of neutrophils under UV irradiation with a pulsed broadband UV source (210 mJ/cm$^2$) was analyzed. The effects of citrate-stabilized CeO$_2$ sol on spontaneous and stimulated by phorbol-12-myristate-13-acetate (PMA) and N-formylmethionyl-leucyl-phenylalanine (fMLP) luminol-dependent chemiluminescence of neutrophils were evaluated. The activating effect of CeO$_2$ nanoparticles on the spontaneous and suppressive effect on the stimulated chemiluminescence of blood neutrophils from apparently healthy donors was shown, with the most pronounced activating effect of CeO$_2$ nanoparticles revealed in the blood sample with initially high radical-producing cell activity. Under UV irradiation of blood at a dose of 210 mJ/cm$^2$ CeO$_2$ nanoparticles enhance both spontaneous and stimulated radical-producing function of neutrophils. Probably, the suppressive and activating effects of citrate-stabilised cerium dioxide sol may be due to the antioxidant activity of CeO$_2$ nanoparticles with respect to hypochlorite ions and prooxidant activity with respect to hydrogen peroxide.