A PBS solution containing only nanoparticles was injected in the tail vein and tracked 2 or 15 days after injection by IVIS to determine the pattern of free nanoparticle distribution in control and chagasic mice. (A) Representative images showing the distribution of X-Sight761 viewed from the ventral surface of the body. (B) Images of ex vivo organs showing the nanoparticle distribution. (C-H) Quantification of fluorescence intensity of ex vivo organs shown in images in B. The evaluated organs were (C) heart, (D) bladder, (E) lung, (F) liver, (G) spleen and (H) kidney. Group abbreviations: CTRL-control mice; 2MAI-2 months after infection; +761 2d or 15d-plus free X-Sight 761 nanoparticles after 2 or 15 days of the administration, respectively. *P<0.05 and **P<0.01.