Fig. 4

In vivo imaging and distribution of PB NZs in healthy and AKI model mice. T₂-weighted MR images of PB NZs in A healthy and B RM-AKI mice at pre-injection (0 h) and different post-injection time points. The injection dose of PB NZs (2 mg/mL) is 200 μL. C Quantitative analysis of the T₂-weighted MR signal-intensity rates in the kidneys of healthy and RM-AKI mice. (n = 3; mean ± SD). D Three-dimensional (3D) photoacoustic (PA) images and E relative PA signal intensities in the kidneys of healthy and RM-AKI mice at different time points following i.v. injection of PB NZs. The injection dose of PB NZs (2 mg/mL) is 200 μL. The scale bar is 1 mm. F Time-dependent accumulation of PB NZs in the kidneys of RM-AKI and healthy mice as measured by ICP-MS. The injection dose of PB NZs (2 mg/mL) is 200 μL