Scientists at Massachusetts General Hospital were able to create "stable and functional" blood vessels in mice using human induced pluripotent stem cells (iPSC). They believe these engineered blood vessels could lead to treatments for cardiovascular disease, creating new pathways for blood circulation.

Researchers used iPSCs — which are reprogrammed adult cells with many properties similar to embryonic stem cells - from people with type 1 diabetes, as well as from healthy adults. Specifically, they wanted to see if vascular precursor cells, which consist of endothelial cells and mesenchymal cells would be able to create blood vessels, HealthDay reported.

"The discovery of ways to bring mature cells back to a 'stem-like' state that can differentiate into many different types of tissue has brought enormous potential to the field of cell-based regenerative medicine, but the challenge of deriving functional cells from these iPSCs still remains," study co-senior author Dr. Rakesh Jain, director of the Steele Laboratory for Tumor Biology at Mass General, said in a hospital news release.

The researchers mixed the two precursor cells in a material that would enable growth and connection. They then injected the mixture into the brain and skin on the back of the mice. Some also had it injected deeper into their backs — these mice died after two weeks, but even they showed early formation of blood vessels that had connected with their own.

"We were able to study the construct in the brain non-invasively every day for 280 days," Dr. Rekha Samuel, a post-doctoral fellow in Jain's lab, said. "It allowed us to measure the functionality of the construct and understand the differences between the vessels of the host and the construct."

The newly formed vessels were much more permeable than those already grown in mice, Samuel said. The endothelial cells, which form the inner lining of the blood vessels, grow differently with each organ. But once they are able to do that, she says it may be able to help restore blood flow in patients where flow is restricted.

"The potential applications of iPSC-generated blood vessels are broad — from repairing damaged vessels supplying the heart or brain to preventing the need to amputate limbs because of the vascular complication of diabetes."

Many diabetics have problems with their feet and extremities, due to poor blood flow. Having this problem can prevent the feet from fighting infection, and can even cause the feet and legs to narrow and harden, sometimes resulting in amputations. Samuel says that this research could help patients with these problems by regenerating pathways for blood circulation.

Similar tests on mice were also done at Okohama City University in Japan, where researchers focused on growing a new liver.