Fig. 4

The fluorescence intensity distribution in the brain and major organs following BSA-LDHs-Cy5.5 I.N. administration. a Fluorescence imaging at specific time points after I.N. delivery (n = 6). b In vitro fluorescence images of mice organs (hearts, livers, spleens, lungs, and kidneys) after 15 min of administration (n = 3). c, d, e Schematic diagrams of the brain (c), liver (d), and kidneys (e) frame selection for fluorescence in vivo imaging and the mean brain, liver, and kidneys fluorescence intensity following I.N. delivery of BAS-LDHs-Cy5.5 and BSA-Cy5.5 (n = 6). f The fluorescence intensity ratio (brain/periphery) associated with BAS-LDHs-Cy5.5 was higher than that measured for BSA–Cy5.5 from 15 min to 24 h (n = 6). Data are represented as fluorescence intensity, expressed as mean ± sem. * p < 0.05; ** p < 0.01; *** p < 0.001