Fig. 4.

Evaluation of PPS targeting capability. (A). Distribution of DiD-stained PPS in vein graft, normal blood vessels and major organs (heart, liver, spleen, lungs and kidneys). Quantitative analysis of the mean fluorescence intensity of the different organs in Fig. (A) was performed at 6 (B), 12 (C) and 24 (D) hours, respectively (n = 3). (E). Fluorescence images of isolated blood vessels (6, 12 and 24 h) from rabbits in the PPS group. (F). Quantitative analysis of the mean fluorescence intensity of isolated blood vessels (n = 3). (G). Plasma concentration-time curves after intravenous injection of sildenafil or PPS in rabbits of the experimental groups (n = 3).