Engineering the Future of Stem Cells in Vascular Reconstruction: A Leap Towards Functional Endothelialized Tissue-Engineered Vascular Conduits.

The transition from reconstructive to regenerative strategies in vascular surgery has intensified the need for grafts that are biocompatible, growth-capable, and resistant to thrombosis. Addressing this challenge, Park et al. introduce a groundbreaking method for engineering fully biological, endothelialized tissue-engineered vascular conduits (TEVCs) using decellularized human umbilical arteries (dHUAs) coated with human induced pluripotent stem cell-derived endothelial cells (hiPSC-ECs). These constructs undergo shear stress training in bioreactors, mimicking physiological blood flow to enhance endothelial functionality and anti-thrombotic properties. Upon implantation in animal models, the grafts showed long-term patency, resistance to thrombosis, and progressive replacement of hiPSC-ECs by host endothelial cells, highlighting their regenerative and integrative potential. The study emphasizes the pivotal role of hemodynamic conditioning and key regulators such as KLF2 in promoting endothelial quiescence and vascular homeostasis. It further explores alternative strategies like endothelial colony-forming cells (ECFCs) and microfluidic systems for flow-induced maturation. Clinically, this approach offers a promising, scalable avenue for patient-specific, immune-compatible vascular grafts applicable in congenital heart disease, dialysis access, vascular grafts and coronary bypass. While challenges such as long-term durability and mechanical reinforcement remain, this research marks a transformative step toward functional, off-the-shelf vascular grafts. Park et al.'s work bridges biomimicry with regenerative medicine, paving the way for next-generation vascular therapies rooted in endothelial mechanobiology and personalized bioengineering.