Fig. 3: Anti-oxidation, selective inhibition of the formation for Aβ fibrils, Aβ fibril degradation, and reaggregation inhibition by NCs.

a Size change of NCs treated with PBS and hydrogen peroxide (H₂O₂) for various times. b Oxygen generation comparison of H₂O₂ that respectively was treated with PBS, 3, and NCs. a, b were representative data of three independent experiments. c Electron spin resonance (ESR) spectra comparison among the PBS group, iron oxide nanoparticles (Fe₃O₄, 100 μg/mL), and the mixture of Fe₃O₄ with NCs, all contain H₂O₂. d Proportion change of various valence states for Ce element in NCs before and after H₂O₂ treatment. e Illustration for the experiment design, including the oxidation promoted the elongation of Aβ fibrils, NCs achieved the fibril degradation, and NCs inhibited the aggregation of monomer and reaggregation of fragments. f Transmission electron microscope (TEM) images of the morphology change of Aβ species from monomer, oligomer to Aβ fibrils during 48 h of growth. g TEM image of Aβ fibril treated with H₂O₂. h TEM images of the fibril degradation and the inhibition of fibril generation treated by NCs for 48 h. i TEM images for the reaggregation of fragments and reaggregation inhibition by NCs. j The corresponding length of fibrils tested by DLS under different conditions. f–j were representative data of three independent experiments. k Positive (blue) and negative (red) electrostatic potential analysis of the DFT-optimized 3. l NIR imaging at 1350 nm of various concentrations of Aβ fibril with 3 (2 μM). m The monitoring of fluorescence intensity at 1060 nm of Aβ fibrils (10 μM) treated with various concentrations of 3. n Absorption at 760 nm of various proteins, bovine serum albumin (BSA), and human serum albumin (HSA) treated with 3. The absorption test was representative of three independent experiments. o CD spectra of Aβ monomer, Aβ fibril (5 μM), and Aβ fibril (5 μM) incubating with 3. Unless otherwise stated, all Aβ peptides in whole assays were Aβ₄₂ (10 μM), and all concentrations of H₂O₂ and NCs were 100 μM and 100 μg/mL. All data were presented as mean ± SEM. NS, no significance, ^***P < 0.001, and ^****P < 0.0001. All statistical analyses were compared by analyses of one-way ANOVA except the two-tailed Student’s t-test in a. Source data are provided as a Source Data file.