Written by Miyako Rogers, Science Writer
In an astonishing new study published in Nature, researchers partially restored organ function in pigs an hour after death from ischaemia. When the blood supply to cells and tissues is blocked, cell death and irreversible damage occurs within minutes. However, this new study challenges this dogma, recovering cells and tissues across multiple vital organs. Researchers have warned that these findings aren’t yet clinically relevant. Nevertheless, by reversing “irreversible” cell death and damage, this study forces us to challenge our current understanding of what death means and what it means to die.
The OrganEx system
OrganEx, a perfusion system that pumps a synthetic blood solution into the animal’s body, re-established circulation and cellular activity in the liver, kidney and heart. OrganEx is based on BrainEx, which was developed in a 2019 study that partially revived the disembodied brains of pigs four hours after the animals died, challenging the concept that brain death is irreversible. While BrainEx was specifically tailored to the brain, OrganEx needed to be able to work on all organs throughout the whole body.
To meet this challenge, researchers developed a synthetic blood solution containing anticoagulants, immunosuppressants and other bioactive compounds to deliver oxygen and reverse cell-death processes. Researchers also had to develop a new perfusion system that would ensure circulation of the blood solution to every organ. The OrganEx system was compared with an extracorporeal membrane oxygenation (ECMO) machine, sometimes used in hospitals as a last resort to restore oxygen to the body. OrganEx restored circulation and oxygen to organs much more effectively than ECMO.
Bringing organs back to life
What researchers then observed was shocking. Cells in vital organs began to respond to glucose and showed metabolic activity. Electrical activity and muscle contraction were detected in the heart, and livers began to produce albumin. The structural integrity of organ tissues was preserved. Transcriptome analysis found that genes involved in cellular repair were activated in all major organs. Given how quickly cell death and decomposition begin after ischemia, these are unprecedented results. If these findings are replicated in other animals and someday in humans, the implications are immense.
Future implications and ethical issues
This technology is still very far away from being used in the clinic. However, if further research supports these findings and organs can be partially revived after death, this could significantly improve the viability of post-mortem organ transplants. The results of this study also raise several ethical questions. If these findings are reaffirmed, it could lead to debates around the legal and medical definitions of death. This has implications for those on life-support and raises the question: How can we confidently declare a person dead? Until the results of this study are replicated and further research is conducted, we can’t make any bold conclusions. However, the results of this study are still exciting and astonishing.