Fig. 4.

Au₃-PEG₅₀₀-FA₃₂ NPs reduced kidney degeneration. (A) UUO mice were treated with a single i.v. dose of Au₃-PEG₅₀₀-FA₃₂ NP, Au₃-PEG₅₀₀ NP, saline, or free FA on day 7 post-UUO surgery, or daily intraperitoneal injections of Captopril from day 7 to day 14. All animals were killed on day 14. (B) Gross appearance of a kidney from naive mice and a CL kidney from UUO mice after treatment with Au₃-PEG₅₀₀-FA₃₂ NP. (C) UUO kidneys of mice treated with Au₃-PEG₅₀₀-FA₃₂ NPs showed the least tissue degeneration. The area inside the dotted region indicates loss of tissue. (D) Histological images of UUO kidneys reveal that mice treated with Au₃-PEG₅₀₀-FA₃₂ NPs had the least tubule injury (arrow). Circle: intact tubule. Representative images from three kidney sections from each mouse, n = 9 mice/group. Locations of the glomerulus, renal tubules, and tubule lumen are annotated as “g”, “t”, and “l”. Mice treated with Au₃-PEG₅₀₀-FA₃₂ NP had significantly (E) lower % of injured tubules and (F) higher UUO kidney-to-body weight ratio than those treated with saline. For (E), statistical significance was evaluated using the nonparametric Kruskal–Wallis H test that does not require the assumption of normality. Data are from n = 5, across one experiment. For (F), statistical significance was evaluated using one-way ANOVA with Tukey’s post hoc test for multiple comparison. Error bars represent mean ± SD. Data are from n = 9, across two experiments. All P values ≤ 0.05 are displayed on the graph.