In vivo imaging of unconjugated and VEGF-QDs during angiogenesis in ischemic legs. (A-H) Typical images of vasculature in control and ischemic legs. These images were generated by overlaying 100 frames (200 ms/frame), each consisting of a 192-pixel square image, using Adobe after effect CS4 9.0.3 software. In model mice injected with VEGF-QDs, we observed “linear vasculature” (A,C,E,G) and “branched vasculature” (B,D,F,H) in control and ischemic mouse legs at 4, 9, and 14 days after operation. The data from unconjugated QDs are not shown (supplemental Figure 2). White dots represent QD fluorescence. Scale bar represents 10 μm. (I) The number of VEGF-QDs in different types of vasculature. The number of fluorescent particles per 10 μm of the vascular wall is quantified. n = 4. **P < .05. Error bars represent SEM.