Figure 4.

In vivo half-life estimation of nanoparticle carriers. (A) Integrated fluorescence intensity of 1-Arg (n = 6), 2-Arg (n = 5), and 3-Arg (n = 3) as a function of time. Solid black line, dashed red line, and dash dot blue line are the corresponding exponential decay fittings. (B) Half-lives of nanoparticle carriers estimated from the (A). Error bar represents 95% confidence interval. The half-life for 3-Arg is more than 240 days. The monitoring was stopped for terminal histological toxicity examination.