People waiting for organ transplants may soon have higher hopes of getting the help that they need in time. Researchers at the RIKEN Center for Developmental Biology have developed a new technique that extends the time that donor organs last and can also resuscitate organs obtained after cardiac arrest.
The work published in Scientific Reports details a procedure that cools organs down to 22 °C (71.6 °F) and slows down organ function while still supplying oxygen, resulting in more successful transplants than the current standard methods. Team leader Takashi Tsuji notes that this system should quickly increase the pool of available donor organs and could even be used to grow whole 3D organs in the future.
(Left) A natural liver. (Middle) A liver preserved using the new perfusion system at 22 degrees Celsius. (Right) A liver preserved using the standard static method at 4 degrees Celsius. Note how much similar in appearance the liver preserved using the new method is to a natural liver. Transplants with these livers proved much more effective than those using livers in the standard method.
Typically, donor organs are kept at a static temperature of 4 °C in preservation solution and have preservation times of only about 6 hours for hearts and lungs, 12 hours for livers, and 20 hours for kidneys. Lengthening these times is a high-priority goal in transplant research, and the team at RIKEN was able to do so using a 3D organ-perfusion system that supplies oxygen to the donor organ and keeps it at an ideal temperature.
Using a rat model for liver transplant, they isolated livers, placed them in culture, and hooked them up to a perfusion system that can pump essential fluids through the organs--including red blood cells, which carry much-needed oxygen.
They assessed liver function at several different temperatures by measuring concentrations of certain protein markers--alanine aminotransferase, which rises in dysfunctional livers, and albumin, which is higher in healthy livers. Analysis of these markers and bile production--another sign of a healthy liver--showed that livers remained healthy the longest--up to 2 days--when preserved at 22 °C with red blood cells added to the perfusion culture.
3D-image analysis showed that when red blood cells were used, fewer liver cells died, and the complex structure of the livers remained intact.
After determining that liver cells cooled to 22 °C--but not lower--will begin to multiply again and exhibit healthy metabolism when warmed, the researchers compared the effectiveness of transplanting livers preserved for 24 hours by their new method with those preserved for 24 hours at the standard static 4 °C. Seven days after the transplant, they cut out most of the recipient's natural liver, and through this manipulation, could be sure that they were only analyzing the function of the transplanted liver.
While only 20% of rats that received statically preserved livers survived after this partial hepatectomy, 100% survived after receiving livers preserved using the new hypothermic perfusion system that included red blood cells. Careful analysis showed that seven days after the partial hepatectomy, the new livers, which had been smaller than normal when transplanted, had grown to acceptable weights, and markers of liver function had returned to normal levels.
The team also tested their system on livers similar to those donated after a person has died from cardiac arrest, which in practice often go unused because they are frequently severely damaged. When red blood cells were added, these livers showed many signs of normal function after transplant, and survival rate was 100% even after partial liver removal seven days after transplant.
In stark contrast, when these types of livers were transplanted using static 4 °C preservation or the new perfusion system without red blood cells, none of the rats survived after the partial hepatectomy.
While there is still a ways to go until this method will be available for humans, Tsuji is optimistic. "Optimizing the scale of the system for humans while still making it portable," he says, "will likely take about 3 years. Once that is accomplished, we should be able to begin the first human trials within a year or two."
Reference: Ishikawa J, Oshima M, Iwasaki F, Suzuki R, Park J, Nakao K, Matsuzawa-Adachi Y, Mizutsuki T, Kobayashi A, Abe Y, Kobayashi E, Tezuka K, Tsuji T (2015). Hypothermic temperature effects on organ survival and restoration. Scientific Reports. doi: 10.1038/srep09563
Adam Phillips | EurekAlert!
NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures
17.11.2017 | National Institute of Standards and Technology (NIST)
High speed video recording precisely measures blood cell velocity
15.11.2017 | ITMO University
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses