Bioengineered Arteries Grown from Stem Cells

Scientists for the first time have produced cells that grow into fully functional arteries and they are on their way to clinical applications. For years, stem cell biologists have unsuccessfully tried to generate arterial cells of good quality to form functioning arteries that would give doctors new options to treat cardiovascular disease which is the number one cause of death in the United States. The report was published in the journal Proceedings of the National Academy of Sciences.

Functioning Arteries Made From Endothelial Cells

In the lab, scientists discovered methods to generate cells (called arterial endothelial cells) that start growing into arteries that exhibit many functions required by the body. Though only tested on mice who all had dying heart tissue, the stem cells were successful in creating new arteries and improved the overall survival rate (83% for the diseased mice, and 33% for the untreated mice). Death from cardiovascular disease in people is mainly due to poorly functioning arteries and the goal is to make more advanced arterial endothelial cells to replace diseased arteries.

According to the American Heart Association, one in three deaths in the United States each year are attributed to cardiovascular disease. The disease claims more lives yearly than cancer. The top priority of scientists in this field is arterial engineering and the challenge is to move away from generic endothelial cells (though easy to make) which are of little clinical value at this point. The researchers have pioneered new technologies to measure the function of candidate genes and gauge the percentage of successful arterial cells generated.

A protocol was developed for arterial cell development by the research group. They also found common growth factors like insulin known to inhibit cell differentiation of arterial endothelial cells. The ultimate goal is to use functioning arteries made from this improved process. According to Professor James Thomson, this study delivers proof that arterial endothelial cells will soon become a reliable source for arteries that perform like the real thing.

Artery Banks of Genetically Compatible Donor Cells

The feasibility project is sponsored by the National Institutes of Health with the hope of creating artery banks for the purpose of human transplantation. The team is finishing the first year of a seven-year study. For bypass surgery, patients with vascular disease often lack suitable artery tissue from their bodies. Using the patient's stem cells to grow arteries is a long process and thus cost prohibitive for clinical use.

The big challenge in producing arteries from arterial endothelial cells is to ensure the methods used are compatible with the patient and not rejected by their bodies. According to lead author Jue Zhang, they now have a method to generate these cells. The focus now is on creating banks of universal donor cells from a small population of donors who are genetically compatible for most patients.