The pigs had been dead for an hour, and yet the cells in their hearts, brains, and liver were still beating.
Thanks to a new system called OrganEx, scientists can now preserve the dying organs of people who recently died pigs alive by connecting the animals to a system of pumps, filters, and flowing fluids. This procedure does not restore the animals Brain function or withdraw the pigs from the great afterlife; Rather, it ensures that certain cell functions are maintained in the animals’ vital organs.
In the future, the system could potentially help preserve and restore donated human organs destined for transplant procedures, scientists reported in a new study published in the journal on Wednesday (Aug. 3). Nature (opens in new tab). This process could increase the number of organs available for transplantation by reversing the effects of ischemia – in which an organ is damaged by insufficient damage blood Flow and oxygenation – in donated organs.
And theoretically, such a device could also be used in living people to treat ischemia that occurs during stroke or heart attack, wrote Dr. Robert Porte, a professor at the Department of Surgery at the University of Groningen in the Netherlands, who was not involved in the study, in an accompanying booklet comment (opens in new tab) work.
However, the technology won’t be applied to living people or donated organs any time soon.
Related: How long can organs remain outside the body before being transplanted?
“This is a far cry from human application,” Stephen Latham, director of the Yale Interdisciplinary Center for Bioethics and co-author of the study, told reporters in a news conference on Tuesday (Aug. 2). The proof-of-concept experiment on pigs showed that the OrganEx system can restore some cellular functions in some organs after blood flow to those organs has stopped, but the degree of restoration differed between organs.
“We would have to learn [in] much more detail the extent to which ischemic damage is reversed in different types of organs before we even come close to doing an experiment like this on a human who has suffered “anoxic damage,” which means organ damage from lack of oxygen, Latham said .
The team plans to study OrganEx in many more animal studies “before even thinking about transferring the technology to humans,” said Dr. David Andrijevic, an associate researcher in neuroscience at the Yale School of Medicine and co-author of the study at the induction.
How OrganEx works
The new research builds on an earlier study published in the journal in 2019 Nature (opens in new tab)in which the researchers used a smaller version of the same system to test some cellular and Metabolism- Activity in the brain of a pig decapitated during food production.
This smaller system, called BrainEx, pumped a liquid brimming with hemopure — a synthetic form of the protein hemoglobin, which carries oxygen in red blood cells — through the blood vessels of the brain. The liquid also contained chemical compounds designed to prevent blood clots from forming and cells from self-destructing through a process called “apoptosis.” Pumping this fluid through the brain prevented the organ from swelling as it normally would after death and allowed certain cellular functions to continue for up to four hours after decapitation. (Importantly, the treated brain did not produce electrical signals associated with normal brain function or “residual consciousness,” the authors confirmed.)
“Cells are actually not dying as fast as we think, which fundamentally opens up an opportunity for intervention,” Dr Studie said at Tuesday’s news conference. In other words, if scientists intervene early enough, they can save some cells from certain death.
In their latest work, the team essentially scaled up their BrainEx system to perfuse an entire pig’s body at once.
The scaled-up system uses a heart-lung machine-like device that takes over the role of the heart and lung during operations by pumping blood and oxygen through the body. The team used this device to pump both pig blood and a modified version of their synthetic, cell-sparing fluid through the bodies of the deceased pigs. Their synthetic solution contained 13 compounds designed to suppress inflammation, stop blood clots from forming, prevent cell death and correct electrolyte imbalances that develop when ischemia sets in.
Related: Creating ‘universal’ transplant organs: New study brings us one step closer.
To test OrganEx, the team induced cardiac arrest in anesthetized pigs and after an hour connected the animals to the device. They compared the OrganEx-treated pigs to pigs treated with an extracorporeal membrane oxygenation (ECMO) system, which pumped only oxygen-rich blood through the animals’ bodies.
After six hours, the team found that ECMO was not adequately perfusing all of the animals’ organs with blood, and many blood vessels collapsed as they normally would after death; the animals treated with ECMO also showed extensive signs of bleeding and tissue swelling. In comparison, OrganEx reduced levels of cell death and improved maintenance of tissues throughout the body.
In addition, pigs treated with OrganEx showed signs of evolving cell repair in the brain, heart, lungs, liver, kidney and pancreas, and these vital organs maintained certain cellular and metabolic functions throughout the six-hour experiment. The heart in particular showed signs of electrical activity and could contract. Further examination of the pigs’ hearts, kidneys and livers also revealed that specific genes involved in cell repair were activated in the organs, while this was not the case in the ECMO-treated pigs.
“This tells us that cell death can be halted and functionality restored in several vital organs even an hour after death,” said Dr. Nenad Sestan, a professor of neuroscience at the Yale School of Medicine and the study’s senior author,” he said at the briefing.
The results suggest that OrganEx, or components of the system, could one day be used to treat ischemia and preserve transplant organs, particularly in “post-cardiac death donation,” in which donor organs are removed from the circulation for some time before transplantation, the authors wrote Porte in his comment. But again, much more research is needed before the system can be applied in either environment.
In follow-up work, the research team aims to better understand how, where and to what extent OrganEx restores cell function in various animal organs. In addition, they must evaluate whether and how their synthetic solution needs to be adapted for use in human tissue. And ethical and practical concerns must be addressed before even considering using the system on living people, Latham said at the briefing.
“You have to think, ‘To what state would a person be restored if they had been seriously damaged by ischemia and given a perfusate that reversed some, but not all, of that damage?'” he said he . “Organ salvage and organ preservation for transplantation is, in my opinion, a much closer and much more realistic clinical goal that could be based on this study.”
Originally published on Live Science.
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