MDA-MB-231 were established as xenografts in nude mice. Nude mice (n = 3–8 per group) were injected intravenously with free 3H-DSPE-PEG-GlcN, 3H-GlcN (0.1 μCi [low dose] or 1.3 μCi [high dose]), 3H-MWCNT-DSPE-PEG-GlcN (0.1 μCi [low dose] or 1.3 μCi [high dose] or PBS control and placed in metabolic cages. (A) Blood samples were obtained 10 min, 60 min and 24 h postinjection, and radioactivity was quantified by scintillation counting. Data are shown as percentage injected dose per ml blood ± standard error. (B) Pooled urine was collected at 0–1 h and (C) 1–24 h after injection, and radioactivity was quantified by scintillation counting. Data in (B) are shown as percentage injected dose per ml urine.
GlcN: Glucosamine; MWCNT: Multiwalled carbon nanotube.