Drug News
Human blood vessels grown in lab mice
By Sue Mueller
Jul 19, 2008 - 12:15:00 PM

SATURDAY JULY 19, 2008 (foodconsumer.org) -- Researchers have successfully grown functional human blood vessels in lab mice using cells from adult human donors, according to a new study in Circulation Research: Journal of the American Heart Association. The success could be an important step in developing strategies to grow issue in a laboratory for treatment of heart attack, acute injuries and wound healing.

“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,” said Joyce Bischoff, Ph.D., senior author of the study and associate professor at Harvard Medical School and Children’s Hospital Boston.

In the study, the researchers first grew a combo of two different types of progenitor cells in a culture dish with nutrients and growth factors, and then implanted purified cells into mice with weakened immune systems. The implanted progenitor cell mixture then grew and differentiated into a small ball of healthy blood vessels.

Two different types of cells used in the study were the endothelial progenitor cells (EPCs), which become cells responsible for lining of the vessels, and mesenchymal progenitor cells (MPCs), which grow to become the cells that surround the lining and provide stability.

The researchers tried a mixture of adult blood- and adult bone marrow-derived progenitor cells and a combination of umbilical cord blood-derived and adult bone marrow-derived cells and found they resulted in the greatest density of new blood vessel formation.

The success in using the progenitor cells to grow blood vessels means that growing tissue does not have to trigger ethical issues resulting from the use of embryonic or umbilical cord blood stem cells.

Bischoff said the success also means that the researchers could solve the problem in treating several medical conditions that resulted from ischemia - the inability of oxygen-rich blood to reach an organ or tissue - such as heart attacks, wound healing and many acute injuries.

“What we are most interested in right now is speeding up the vascularization (the formation of blood vessels),” 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, it’s dying tissue, so the faster you can establish blood flow the better.”