Public Release: 

Researchers step closer to custom-building new blood vessels

Vessels grown from pluripotent stem cells able to function inside mice

Johns Hopkins Medicine


IMAGE: Shown are lab-grown human blood vessel networks (red) incorporating into and around mouse networks (green). view more

Credit: PNAS



Gerecht's research group and others had previously grown blood vessels in the laboratory using stem cells, but barriers remain to efficiently producing the vessels and using them to treat patients.

For the current study, the group focused on streamlining the new growth process. Where other experiments used chemical cues to get stem cells to form cells of a single type, or to mature into a smorgasbord of cell types that the researchers would then sort through, graduate student Sravanti Kusuma devised a way to get the stem cells to form the two cell types needed to build new blood vessels -- and only those types. "It makes the process quicker and more robust if you don't have to sort through a lot of cells you don't need to find the ones you do, or grow two batches of cells," she says.

A second difference from previous experiments was that instead of using adult stem cells derived from cord blood or bone marrow to construct the network of vessels, Gerecht's group teamed with Linzhao Cheng, Ph.D., a professor in the Institute for Cell Engineering, to use induced pluripotent stem cells as their starting point. Since this type of cell is made by reverse-engineering mature cells -- from the skin or blood, for example -- using it means that the resulting blood vessels could be tailor-made for specific patients, Kusuma says. "This is an elegant use of human induced pluripotent stem cells that can form multiple cell types within one kind of tissue or organ and have the same genetic background," Cheng says. "This study showed that in addition to being able to form blood cells and neural cells as previously shown, blood-derived human induced pluripotent stem cells can also form multiple types of vascular network cells."

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.




The study was funded by the American Heart Association, the National Heart, Lung, and Blood Institute (grant numbers F31HL112644, 2R01 HL073781 and R01 HL107938), the National Cancer Institute (grant number U54CA143868) and the National Science Foundation (grant number 1054415).

Other authors on the report were Yu-I Shen, Donny Hanjaya-Putra and Prashant Mali, all of The Johns Hopkins University.

Link to the PNAS article:

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