PMC

Confocal image projection of one end of a rod-shaped 1:4 human endothelial cell to fibroblast-derived prevascular tissue construct after 3 days of culture. Human endothelial cells are labeled with anti-CD31 (red) and show organization of a primary network pattern in vitro. 20×

Stereo microscopic images of a prevascular tissue xenograft 3 days after implantation in an immune-competent rat. A: en face view of the xenograft (yellow dashed line) attached to host muscle. B: Red blood cells are visible in vascular network patterns throughout the xenograft (C: higher magnification).

Immunofluorescence images of tissue sections of a prevascular tissue xenograft 3 days after implantation in a hind limb muscle defect in an immune-competent rat showing activated satellite cells migrating into the xenograft. A: Pax-7 (red), Hoechst (blue); 20×. B: MyoD (red), Hoechst (blue); 20× confocal image projection. Arrows indicate activated satellite cells (A) and nascent myotubes (B). Quantification of satellite cells was not significantly different at day 3 compared to sham controls (p<0.05, Student’s t-test).

Immunofluorescence images of 10μm frozen section of prevascular tissue xenografts and surrounding host tissue after 3 (A), 7 (B), and 14 (C) days in hind limb muscle defects in athymic mice. The prevascular constructs were pre-labeled with Qtracker^™ 655 Quantum Dots (yellow) during in vitro culture. CD31-labeled blood vessels (red) indicate xenograft vascularization by the host vasculature. Nuclei are labeled in blue. 20×. Quantification of vasculature of day 7 constructs showed a significant difference as compared to controls, and day 7 vasculature was likewise significantly different than day 14 (p<0.05, ANOVA).

Light microscopic images of Hematoxylin and Eosin stained tissue sections of a prevascular tissue xenograft 3 days after implantation in an immune-competent rat. Xenograft is outlined with dashed yellow line (A); host muscle is oriented to the bottom region of the images (yellow asterisks). Presence of red blood cells in the lumens of vessels (yellow arrows) indicates the xenograft anastomosed to the host vasculature. Image in C shows a higher magnification region from the middle of the xenograft, distal from the implant-host border zone. A: 10×; B: 20×; C: 40×.