Iron oxide nanoparticles cause surface coating- and core chemistry-dependent endothelial cell ferroptosis

Iron oxide nanoparticles (IONPs) are mostly intended to be administrated intravenously, understanding the interaction of IONPs with vascular endothelial cells is extremely crucial for developing safe application regimes of IONPs. In this work, interactions of three kinds of IONPs to endothelial cells were investigated both in human umbilical vein endothelial cells (HUVECs) and in healthy mice. Both meso-2,3-dimercaptosuccinic acid (DMSA) coated Fe3O4 NPs (DMSA-Fe3O4 NPs) and DMSA-Fe2O3 NPs induced cell growth inhibition, while polyglucose sorbitol carboxymethyether coated Fe2O3 NPs(PSC-Fe2O3 NPs) did not. The PSC coating inhibited the cellular uptake of the IONPs. Both DMSA-Fe3O4 and DMSA-Fe2O3 NPs induced ferroptosis of HUVEC through upregulating phospholipid peroxides, which could be inhibited by typical ferroptosis inhibitors ferrostatin-1, Trolox and deferoxamine. Moreover, transforming growth factor beta 1 (TGFβ1) was upregulated by DMSA-Fe3O4 NPs at protein and gene level. The inhibitor of TGFβ1 receptor LY210 could reduce the effect. When being intravenously injected in mice, DMSA-Fe3O4 NPs were observed locating in the liver, increased the levels of lipid peroxidation (4-hydroxynonenal), acyl-CoA synthetase long-chain family member 4(ACSL4) and TGFβ1, indicating ferroptosis occurrence in vivo. The ferroptosis of vascular endothelial cells in exposure with IONPs depended on the surface coating and core chemistry of the NPs. Both DMSA-Fe3O4 NPs and DMSA-Fe2O3 NPs could induce the ferroptosis of endothelial cells, while PSC-Fe2O3 NPs did not induce ferroptosis and apoptosis possibly due to the very low cellular uptake. DMSA-Fe3O4 NPs and TGFβ1 formed feedforward loop to induce ferroptosis.