Methods: hESC-ECs and/or hESC-vSMCs were embedded within a PEGylated fibrin gel and cultured for varying periods. The ability of these cells to form in-vitro vascular networks was assessed by confocal microscopy. Then, these in-vitro vascularized tissue constructs were embedded within collagen gels to analyze their ability for inosculation.
Results: When hESC-ECs were used alone, they formed few cord-like structures and were unable to mature into vascular networks. The co-culture of hESC-ECs and hESC-vSMCs formed extensive vascular networks. The hESC-vSMCs were seen to be closely associated with the endothelial tubes suggesting the supportive role played by the mural cells. In-vitro vascularized constructs when embedded within collagen gels, showed sprouts of vascular tubes into the collagen gel.
Conclusions: Our findings demonstrate the potential of hESC derived vascular cells for fabrication of in-vitro vascularized tissue constructs. These tissue constructs could be used for various tissue engineering purposes, and to study 3-dimensional vascular biology.