Extended Data Fig. 3.

a, Assessment of serum stability of ⁸⁹Zr-radiolabeled SWNTs demonstrates no signs of instability for up to 7 days at 37°C in fresh mouse serum. Data are representative of 3 independent experiments. b, Fluorescence-based studies show that the blood half-life (t_1/2) of SWNT-Cy5.5 measures ~2hr, indicating that desferrioxamine chelation of ⁸⁹Zr to SWNT-Cy5.5 does not significantly alter the circulation time of the nanoparticles used in the formal biodistribution studies (n = minimum 4 biologically independent animals per time point). Mean and s.e.m. are shown. c, Representation flow cytometry plots and gating strategy for analysis of SWNT uptake in homogenized organs. d, Immunofluorescence imaging shows SWNT (immunostained for PEG) accumulation in the aortic sinus, with lesser amounts in the spleen and liver, and little-to-no accumulation in other organs such as healthy aorta, lung, and kidney after 4 weeks of weekly serial injections. Data are representative of a minimum of 3 independent experiments. Scale bars, 100 μm.