Fig. 6: In vivo fluorescence imaging and biodistribution of I-43 in WT and APP-PS1 mice.
a Fluorescence imaging micrographs showing radiance efficiency changes of I-43 in 13- and 6-month-old APP-PS1 and 13-month-old WT mice after 0.8 mg/kg intravenous administration. Scalp imaging was performed at representative time points (n = 3 biologically independent mice; λex/em = 500/690 nm; Lago-X from Spectral Instruments Imaging, equipped with desirable filter sets). b The radiance efficiency vs time plot showed higher signal intensity in APP-PS1 mouse brains than WT mice throughout the study (n = 3). c The bar graph showed significant differences in fluorescence intensity (**P = 0.0024) between APP-PS1 mice (13-month-old; n = 3) and age-matched WT mice at 60 min post i.v. route dosing of I-43, while a significant difference compared to the background (Bkg) or untreated control (Data represent mean ± SD; significance levels: ***P = 0.0001, **P = 0.001, *P = 0.040 vs Bkg, and **P = 0.0024 (WT vs 13-month APP-PS1); one-way ANOVA with Dunnett’s post hoc test). Data from the remaining two mice from each group are provided as Supplementary Fig. 58a–c. d Ex vivo NIR imaging at 700 nm of intact excised brains from 13-month-old WT and APP-PS1 mice, resected 20 min after intravenous administration of 0.8 mg/kg I-43. Cryo-sectioned slices were imaged under an NIR confocal microscope to locate Aβ deposits in APP-PS1 mice brains with I-43 at a 700 nm filter set (Scale bar: 50 µm; LSM 780 equipped with axio imager 2). e Ex vivo biodistribution study of I-43 in 6-month-old APP-PS1 mice following intravenous administration of a 0.8 mg/kg dose. Major organs, including the liver, spleen, kidney, brain, lung, and heart, were resected at 20 min post-injection and used for fluorescence imaging. e1 The bar graph shows fluorescence signal intensity profiling (photon counts) of I-43 in the organs resected from APP-PS1 mice (n = 4 independent mice). Data represent mean ± SD, one-way ANOVA with Dunnett’s post hoc test: **P = 0.0025 (Liver); nsP = 0.0636 (Lungs); nsP = 0.0655 (Heart); ****P < 0.0001 (Spleen); nsP = 0.2224 (Kidney), all compared to Brain signals. Source data are provided as a Source Data file.
