Figure 8: Fluorescence intensities of different organs taken at 5 min, 20 min, 1 h and 24 h post i.v. injection into mice tail veins. 12 mice (each experiment group contained 3 mice) were anesthetized and treated with NIR fluorescent P(EF-PLLA) nanoparticles (2 mg/mL, 0.01 mg/kg body weight per mouse). Blood was drawn and organs were harvested at each time point. 2 uninjected mice served as negative control. The experiment was repeated twice with similar results.