Bioengineered human vascular networks transplanted into secondary mice reconnect with the host vasculature and...

The ability to form anastomoses with the host circulation is essential for vascular networks incorporated within cell-seeded bioengineered tissues. Here, we tested whether and how rapidly human endothelial colony forming cell (ECFC)/mesenchymal progenitor cell (MPC)-derived bioengineered vessels, originally perfused in one mouse, could become reperfused in a secondary mouse. Using in vivo labeling with a systemically injected mixture of human- and murine-specific lectins, we demonstrate that ECFC/MPC blood vessels reconnect and are perfused at day 3 after transplantation. Furthermore, we quantified the longitudinal change in perfusion volume in the same implants before and after transplantation using contrast-enhanced micro-ultrasonic imaging. Perfusion was restored at day 3 after transplantation and increased with time, suggesting an important new feature of ECFC/MPC blood vessels: the bioengineered vessels can reconnect with the vasculature when transplanted to a new site. This feature extends the potential applications of this postnatal progenitor cell-based technology for transplantable large tissue-engineered constructs.