Washington: Researchers have developed human induced-pluripotent stem cells (iPSCs) which are capable of repairing damaged retinal vascular tissue in mice.
The stem cells, derived from human umbilical cord-blood and coaxed into an embryonic-like state, were grown without the conventional use of viruses, which can mutate genes and initiate cancers, according to the scientists.
Their safer method of growing the cells has drawn increased support among scientists, they say, and paves the way for a stem cell bank of cord-blood derived iPSCs to advance regenerative medicine research.
"We began with stem cells taken from cord-blood, which have fewer acquired mutations and little, if any, epigenetic memory, which cells accumulate as time goes on," Elias Zambidis from Johns Hopkins Institute for Cell Engineering and the Kimmel Cancer Center said.
Instead of using viruses to deliver a gene package to the cells to turn on processes that convert the cells back to stem cell states, Zambidis and his team used plasmids, rings of DNA that replicate briefly inside cells and then degrade.
Next, the scientists identified high-quality, multipotent, vascular stem cells generated from these iPSC that can make a type of blood vessel-rich tissue necessary for repairing retinal and other human material.
They identified these cells by looking for cell surface proteins called CD31 and CD146.
Zambidis said that they were able to create twice as many well-functioning vascular stem cells as compared with iPSCs made with other methods, and, "more importantly these cells engrafted and integrated into functioning blood vessels in damaged mouse retina."
The study was published in the journal Circulation.
