(Image courtesy of Johns Hopkins. The arrows show the blood vessels constructed from stem cells).

Researchers at Johns Hopkins continue their progress on using stem cells and a human made matrix to build blood vessels outside the body and then successfully transplant the blood vessels into mice. They further explained their work as follows:

"To grow the vessels, the research team put the stem cells into a scaffolding made of a squishy material called hydrogel. The hydrogel was loaded with chemical cues that nudged the cells to organize into a network of recognizable blood vessels made up of cells that create the network and the type that support and give vessels their structure. This was the first time that blood vessels had been constructed from human pluripotent stem cells in synthetic material.

To learn whether the vessel-infused hydrogel would work inside a living animal, the group implanted it into mice. After two weeks, the lab-grown vessels had integrated with the mice’s own vessels, and the hydrogel had begun to biodegrade and disappear as it had been designed to do. "That these vessels survive and function inside a living animal is a crucial step in getting them to medical application," Kusuma says.