Biodistribution of PEG-SWCNT-750 in isolated maternal organs. 24 hrs after the injection, maternal organs were collected and fluorescence recorded. A: with the exception of the brain (a), all organs from animals injected with PEG-SWCNT-750 (right column) displayed much higher fluorescence than the controls (left column). b: lung; c: heart; d: brown fat; e: thymus; f: pancreas; g: spleen; h: kidney. B: comparison of fluorescence distribution in liver from dams that were exposed to PBS (a), Seta750 (b) or PEG-SWCNT-750 (c).