How Endothelial Cells Can Be Used for Tissue Engineering

Scientists have turned to primary ECs, which have the innate ability to produce blood vessels, and are understanding the potential of endothelial cells in tissue engineering.

FREMONT, CA: For many years, mature human endothelial cells derived from human vasculature were the primary tool used to research the biology of human endothelial cells. The successful isolation of endothelial cells (ECs) from human umbilical veins was of utmost significance and gave researchers worldwide unheard-of access to human EC cultures. Consequently, endothelial cells established themselves as a major tool in vascular biology research, dominating the area.

To integrate such pre-existing vascular networks, scientists have turned to primary ECs, which have the innate ability to produce blood vessels. There is general agreement that using ECs is necessary for this effort, and bioengineering vascular networks is still a primary focus in tissue engineering.

Human Umbilical Vein Microvascular Endothelial Cells (HUVECs)

Earlier, endothelial cells from umbilical cord veins were the most successfully isolated and propagated in vitro. Today, it has become a staple tool in vascular biology research. HUVECs continue to be the most popular human EC source in bioengineering, although there are alternative stem or progenitor cell sources in development.

There are many causes for this ubiquity, especially the fact that HUVECs have been researched for much longer than any other sources of human ECs. HUVECs have become the best alternative for the development of procedures and standard assays in vascular biology and angiogenesis research due to the knowledge that has been acquired about them over time. This insight has given HUVECs an advantage over competing options.

These cells are extensively available in research labs and commercial businesses as a result of the development of common assays that need HUVECs. However, HUVECs have a short lifespan in culture, limiting the clinical applications they can be used for in an autologous setting. Therefore, additional EC sources produced from pluripotent stem cells or progenitor cells will outperform HUVECs in the future.

Human Dermal Microvascular Endothelial Cells (HDMECs)

Besides HUVECs, endothelial cells isolated from small-diameter veins of skin microvasculature are also studied sources of primary human endothelial cells. The HDMEC that line the blood arteries of the skin demonstrate various skin-specific traits in addition to sharing characteristics with endothelial cells found in other body parts. They actively take part in various physiological activities like temperature regulation, hemostasis management, and wound healing. The endothelial lining of blood vessels exhibits excellent heterogeneity through signalling pathways regulating cell proliferation, quiescence, and apoptosis.

Human Endothelial Progenitors

Human endothelial progenitors derived from circulating human peripheral blood are of widespread interest as a minimally invasive, more replicative cell source with a significant ability to form colonies in vitro. For therapeutic interventions, identifying endothelial progenitor cells in the blood is an efficient procedure to obtain the needed endothelium population without using any intrusive methods.

These cells are often referred to as endothelial colony-forming cells. In addition, their fundamental applications demonstrated that endothelial progenitors were integrated into the graft and formed perfused vasculature, linking up with arriving host vessels. This is the first in vivo demonstration of the use of human ECFCs in the bioengineering of the human vascular system.