Nov. 1, 2017
- Researchers at the University of Minnesota have created a new lab-grown blood vessel replacement that is composed completely of biological materials, but surprisingly doesn’t contain any living cells at implantation. The vessel, that could be used as an “off the shelf” graft for kidney dialysis patients, performed well in a recent study with nonhuman primates.
It is the first-of-its-kind nonsynthetic, decellularized graft that becomes repopulated with cells by the recipient’s own cells when implanted. The discovery could help tens of thousands of kidney dialysis patients each year. The grafts could also be adapted in the future for use as coronary and peripheral bybass blood vessels and tubular heart valves.
The research was published today as the cover story in Science Translational Medicine, an interdisciplinary medical journal by the American Association for the Advancement of Science (AAAS). The University of Minnesota has also licensed the technology.
In this pre-clinical study, University of Minnesota researchers generated vessel-like tubes in the lab from post-natal human skin cells that were embedded in a gel-like material made of cow fibrin, a protein involved in blood clotting. Researchers put the cell-populated gel in a bioreactor and grew the tube for seven weeks and then washed away the cells over the final week. What remained was the collagen and other proteins secreted by the cells, making an all-natural, but non-living tube for implantation.
“We harnessed the body’s normal wound-healing system in this process by starting with skin cells in a fibrin gel, which is Nature’s starting point for healing,” said University of Minnesota Department of Biomedical Engineering Professor Robert Tranquillo who led the study. “Washing away the cells in the final step reduces the chance of rejection. This also means the vessels can be stored and implanted when they are needed because they are no longer a living material. In the future, thousands of the lab-grown vessels could be made from a small skin biopsy from one donor and then stored on the shelf for when they are needed by patients.”
With the success of this study, Tranquillo and the team will seek FDA approval for clinical trials in children with pediatric heart defects since they recently reported a study in Nature Communications that this material is also capable of growing.
In addition to Tranquillo who also has a faculty appointment in the Department of Chemical Engineering and Materials Science, the University of Minnesota research team included lead author Zeeshan H. Syedain, Department of Biomedical Engineering; Melanie L. Graham, Preclinical Research Center; Ty B. Dunn, Department of Surgery; Timothy O’Brien, Department of Veterinary Population Medicine; Sandra L. Johnson, Department of Biomedical Engineering; and Robert J. Schumacher, Center for Translational Medicine.
The research was funded by a private grant the John and Nancy Lindahl Children’s Heart Research Innovators Fund and the University of Minnesota Center for Translational Medicine.
To read the full news release written by Rhonda Zurn, College of Science and Engineering and Lacey Nygard, University News Service, click on the link below.
Photo Caption: Researchers at the University of Minnesota have created a new lab-grown blood vessel replacement that is the first-of-its-kind nonsynthetic, decellularized graft that becomes repopulated with cells by the recipient’s own cells when implanted. Credit: University of Minnesota
Related Link: https://cse.umn.edu/news-release/new-tissue-engineered-blood-vessel-replacements-one-step-closer-human-trials/