The hardest part of organ transplant surgery is the inability to find the right donor. But future liver transplants may not have to wait for the donor to arrive. Recently, a team of researchers at the University of Pittsburgh successfully implanted stem cells into rats and successfully developed a miniature human liver. It should be noted that while scientists have planted induced pluripotent stem cells (IPSCs) in rats, there are still many hurdles to overcome before the technology can truly save lives.
Stem cells create miniature human liver (photo: UPMC)
At present, the primary problem facing organ transplantation is the shortage of donors. Second, even if a transplantable donor is found, the patient’s immune system will have a rejection response.
With this in mind, researchers at the University Medical Center at Pittsburgh simply changed their mind: using the patient’s ontital stem cells to induce the transplanted organs needed.
In the proof-of-concept study, researchers at the University of Pittsburgh first extracted human cells and transplanted them into rats.
Human skin cells used in the experiment were taken from the volunteer population and reprogrammed to become induced pluripotent stem cells (IPSCs).
In theory, IPSC cells can be differentiated into different organs as needed, in this case liver cells, and the team then spread them into the livers of rats that have stripped all their cells and left a “stent” and “pipe” empty.
The team transplanted the miniature human liver into five rats and monitored their condition for four days. As a result, in all cases, the new organs have been working. Tests found that it was secreting bile acid and urea, and that human liver protein was detected in rat serum.
Rats receiving micro-human liver transplants (pictured: Alejandro Soto-Gutierrez)
However, the obstacles to allogeneic transplantation did not completely disappear, as all five rats had blood flow problems in the area around the transplant.
And scientists have engineered the animals to resist the rejection of allogeneic organs, meaning they may not be effective in common animal experiments.
Even so, scientists are optimistic about the future of the technology. A few years ago, for example, a team performed a similar ‘mini-heart’ transplant.
The tiny organs are expected to grow to use in actual human transplants one day, and the team is testing more drugs in rats.
Alejandro Soto-Gutierrez, senior author of the study, said the long-term goal is to create an alternative version of organ donation, and that patients with acute liver failure may only need a period of liver strengthening treatment without replacing the entire liver.
Details of the study have been published in the recent journal Cell Reports.
Originally published as Assembly and Function of Bioengineered Human Liver for Age Generated S Induced Pluripot Stem Cells.