According to a US journal report, scientists have for the first time succeeded in using human cells to grow blood vessels in mice. The team at Harvard Medical School and Children's Hospital Boston reported that the progenitor cells teamed up to form working blood vessels that connected to the circulatory systems of the mice.  Experts hope to find a way to replace arteries that are damaged or blocked in a heart attack or stroke using this technique.

Harvard's Joyce Bischoff, who led the study said, "what's really significant about our study is that we are using human cells that can be obtained from blood or bone marrow rather than removing and using fully developed blood vessels.”

According to the report in the journal Circulation Research, published by the American Heart Association, researchers used immature cells also known as progenitor cells, which are grown under special lab conditions before they were implanted in the mice. Once implanted, the cells grew and differentiated into a small batch of healthy blood vessels. The researchers used progenitor cells, which mature into cells that line the blood vessels, and mesenchymal progenitor cells, which differentiate into the cells that surround the lining and provide stability. The best results, they felt were from a mixture of cells from adult blood and bone or from the umbilical cord blood. Unlike controversial stem cell therapies, which require cells taken from an embryo, these progenitor cells can be from the blood or bone marrow of an adult, or from the umbilical cord.

"What we are most interested in right now is speeding up the vascularization," Bischoff said. "We see very good and extensive vasculature in seven days and we'd like to see that in 24 or 48 hours. If you have an ischemic tissue, its dying tissue, so the faster you can establish blood flow the better."

An expert felt that the research was promising and could eventually help lab grown organs being successfully transplanted. Dr Bischoff said, "What’s really significant about our study is that we are using human cells that can be obtained from blood or bone marrow rather than removing and using fully developed blood vessels."

Dr Nick Rhodes, from the UK Centre for Tissue Engineering at the University of Liverpool said, "It could certainly assist in the connection of other engineered organs to the body's blood supply. Although this approach is not yet suitable for clinical use, it is interesting that they have demonstrated you have all the elements you need to create a functional network of capillaries from a small amount of blood."