A couple tablespoons of fat from a “nip-tuck” procedure in a plastic surgeons’ office provides enough stem cells to seed a collection of new small-diameter blood vessels, according to a July 25 report by senior staff writer Crystal Phend, of MedPage Today. Engineers at the University of Oklahoma’s School of Chemical, Biological and Materials Engineering in Norman, Oklahoma, took cells from a patent’s fat tissue, cultured it into sheets and rolled it into tiny blood vessels. According to Matthias Nollert, Ph D., the vessels performed as well as natural vessels on the test of elastic contractility.
Phend explained the procedure. The stem cells, which are associated with the vasculature in the fat rather than the fat itself, are differentiated into smooth muscle cells in the lab. These cells are “seeded” onto a sheet of decellularized collagen from discarded placenta tissue. In a process that takes three to four week, the cells colonize the scaffold which is rolled into a tube of the desired diameter.
The new vessels are not perfect. According to the researchers, the engineered vessels need to withstand as much pressure as a native vessel can take without bursting. “The burst pressure is still too low, ” Nollert said. “We get burst pressures about 150 mm Hg, and native tissue is around 1, 000 mm Hg.” The problem appears to be that the layers of the rolled-up vessel aren’t adhering well to one another, he explained.
According to Phend, the researchers are trying out some new ideas using tissue glue or other types of glue to hold these layers together. As Nollert explained, “What we really have right now is a neat idea without having the data to show that it’s going to work.” The group hopes to soon move into testing the vessels in animals.
