3D Bioprinting of Thick Adipose Tissues with Integrated Vascular Hierarchies

Engineering functional, thick tissues with integrated vascular architectures is crucial for advancing regenerative medicine. This study applied a novel 3D bioprinting strategy to construct thick adipose tissues featuring complex, hierarchical vascular networks. Mature adipocytes and endothelial cells are encapsulated within a collagen matrix, with structural integrity and vascular functionality ensured through a combination of bioinks. An innovative approach is utilized to establish millimetric vascular channels that connect to microvascular networks, forming a fully perfusable, hierarchical vasculature throughout the 3D bioprinted tissue. The structural stability and endothelial functionality of the vascularized constructs are assessed under continuous flow. In-vitro analyses confirmed the integrity of the vascular networks and demonstrated the functional characteristics of the printed mature adipose cells. Direct anastomosis of the bioprinted tissue to a rat femoral artery resulted in effective vascular integration and tissue viability, as evidenced by efficient blood perfusion and significant host vascular ingrowth within the implanted tissues. The findings highlighted the potential of the presented bioprinting technique in the development of fully functional, vascularized adipose tissues suitable for surgical reconstruction and regenerative medicine applications.