Erythrotoxicity of iron-doped cerium oxide nanoparticles is mediated by eryptosis

  • Toxicol Lett. 2026 Jun:421:111922. doi: 10.1016/j.toxlet.2026.111922.
Volodymyr Prokopiuk  1 ,  Mykyta Lupan  2 ,  Ganna Grygorova  2 ,  Yevgen Posokhov  3 ,  Pavel Maksimchuk  2 ,  Liliya Tryfonyuk  4 ,  Nadiia Shevchenko  5 ,  Lesya Demchenko  6 ,  Kateryna Kot  7 ,  Saulesh Kurmangaliyeva  8 ,  Ondrej Havranek  9 ,  Vladyslav Seminko  2 ,  Anatolii Onishchenko  5 ,  Yurii Kot  7 ,  Svitlana Yefimova  2 ,  Anton Tkachenko  10
Affiliations
  • 1. Department of Cryobiochemistry, Institute for Problems of Cryobiology and Cryomedicine of the National Academy of Sciences of Ukraine, 23 Pereyaslavskaya st, Kharkiv 61015, Ukraine; Research Institute of Experimental and Clinical Medicine, Kharkiv National Medical University, 4 Nauky ave, Kharkiv 61022, Ukraine.
  • 2. Department of Nanostructured Materials, Institute for Scintillation Materials of the National Academy of Sciences of Ukraine, 60 Nauky ave, Kharkiv 61072,Ukraine.
  • 3. Department of Organic Chemistry, Biochemistry, Paints and Coatings, The National Technical University "Kharkiv Polytechnic Institute", 2 Kyrpychova st, Kharkiv 61000, Ukraine.
  • 4. Institute of Health, National University of Water and Environmental Engineering, 11 Soborna st, Rivne 33028, Ukraine; Rivne Regional Clinical Hospital, 78g Kyivska st, Rivne 33007, Ukraine.
  • 5. Department of Cryobiochemistry, Institute for Problems of Cryobiology and Cryomedicine of the National Academy of Sciences of Ukraine, 23 Pereyaslavskaya st, Kharkiv 61015, Ukraine.
  • 6. Department of Chemistry, Stockholm University, Svante Arrhenius väg 16C, Stockholm, SE-106 91 Sweden; Ye.O.Paton Institute of Materials Science and Welding, National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", 37 Beresteiskyi ave, Kyiv 03056, Ukraine.
  • 7. Department of Biochemistry, V. N. Karazin Kharkiv National University, 4 Svobody sq, Kharkiv 61022, Ukraine.
  • 8. Department of Microbiology, Virology, and Immunology, West Kazakhstan Marat Ospanov Medical University, 68 Maresyev st, Aktobe 030000, Kazakhstan.
  • 9. BIOCEV, First Faculty of Medicine, Charles University, Průmyslová 595, Vestec 25250, Czech Republic; First Department of Medicine - Hematology, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic.
  • 10. BIOCEV, First Faculty of Medicine, Charles University, Průmyslová 595, Vestec 25250, Czech Republic. Electronic address: [email protected].
PMID: 42155689 DOI: 10.1016/j.toxlet.2026.111922
Abstract

Iron doping has been reported to significantly modify the properties of metal oxide nanoparticles (NPs), including their interaction with cells and therefore toxicity. The present study explores the ability of Fe³ ⁺-doped CeO2 NPs with the varying content of Fe3+ ions (3, 5, and 10 at%) to stimulate eryptosis, a controllable cell death pathway of mature erythrocytes, as an attempt to shed light on hemocompatibility of iron-doped CeO2 NPs. Overall erythrotoxicity of iron-doped CeO2 NPs was evaluated by investigating their ability to trigger spontaneous hemolysis and affect osmotic fragility of rat erythrocytes. Eryptosis of erythrocytes exposed to iron-doped and non-doped CeO2 NPs for 24 h was evaluated by the state-of-the-art flow cytometry-based annexin V staining. Mechanisms involved in iron-doped CeO2 NP-induced eryptosis were evaluated by 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) and Caspase-3 assays, as well as the fluorescent O1O (2-(2'-hydroxy-phenyl)-5-phenyl-1,3-oxazole), NR12S, Fluo-3 AM, BODIPY™ 581/591 C11, and BioTracker Far-red Fe2+ Live Cell imaging probes. Dose-dependent effects of iron-doped CeO2 NPs on hemolysis, osmotic fragility, and eryptosis were revealed. Eryptosis triggered by iron-doped CeO2 NPs was found to be oxidative stress-mediated, cation channel-driven, and caspase-dependent. Oxidative stress and alterations of lipid membranes demonstrated by the tested NPs could be attributable to their direct •OH generation and peroxidase-like activity, as well as Fe2+-mediated Fenton reaction at the surface of Fe³⁺-doped CeO₂ NPs (presumably due to Fe³⁺/Fe²⁺ redox cycling). Importantly, non-doped CeO2 NPs did not promote eryptosis. Nor they stimulated generation of ROS and CA2+ influx. The presence of iron was found to mediate phosphatidylserine externalization, Caspase activation, and changes in lipid membranes of erythrocytes. Notably, Fe³⁺-doped CeO2 NP-induced eryptosis was independent of p38 MAPK and CK1α. Iron-doped CeO2 NPs trigger eryptosis, an effect mediated by iron. Iron doping is a promising modification of CeO2 NPs, which can modulate their toxicity and widen their pharmaceutical profile.

Keywords
Caspase; Cell death; Cytotoxicity; Eryptosis; Nanotoxicity; Reactive oxygen species; Regulated cell death.
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