Biodistribution of 5-FA (A) and 5-FA-PAE (B) after <i>i.v.</i> injection.

<p>The tumor-bearing animal model was established by subcutaneous injection of H22 cells into Kunming mice. The control group and the test groups were administered intravenously with 20 mg/kg of 5-FA or 5-FA-PAE (equivalent to 20 mg/kg of 5-FA), respectively. The mice were exsanguinated and sacrificed at predetermined time points. Tissues (heart, liver, spleen, lung, kidney, brain and tumor) were collected, weighed and homogenized with two fold concentrated physiological saline. The samples of the test group were treated as hydrolyzed samples, whereas those of the control group were treated as unhydrolyzed samples. All data are presented as the concentration of 5-FA. Each value represents the mean ± standard deviation (n = 6).