Scientists in Cork have found and developed a stem cell that can grow replacement blood vessels in the laboratory. These can then be transplanted into rodents.
A similar stem cell known to exist in humans could be used to make lab-grown human blood vessels, but also potentially other tissues including the bladder and possibly the oesophagus. Trials of the tissues in humans could come within five years, said ProfNoel Caplice, director of the centre for research in vascular biology at University College Cork and a cardiologist at Cork University Hospital.
The stem cells seem willing to grow almost without limit which means unlimited tissue replacement potential, he said. And just one gene is enough to change the stem cells into “smooth” muscle cells.
“Stem cell technology has involved a lot of hope and a lot of hype, but not much tissue or organs have been made outside the body,” he said.
Aorta
Prof Caplice has successfully grown an aorta, the largest blood vessel in the body and used it as replacement tissue in a rodent. The vessel had normal function and the animal survived with it for months.
It took years of research to track down this rare kind of stem cell he calls a “primitive progenitor cell”, but once found in rodents a similar search in humans yielded a very similar cell. These can be reprogrammed to become smooth muscle cells.
He described the work as “a major breakthrough in the field of blood vessel replacement” given their ability to grow.
It is assumed that if used in humans, the recipient of the blood vessel would also be the donor of the starter cells so there would be no rejection.
The stem cell work is important given 30 per cent of patients have blood vessels that are unsuitable for bypass surgery, he said.
It also opens up the potential of replacements for organs made of smooth muscle tissue, such as the bladder, ureter, urethra and oesophagus.
