A group of scientists from Ottawa University in Canada have developed a system which creates antifreeze liquids that can keep organs awaiting a transplant fresh for longer periods of time. This discovery will improve the organ transplant success rate and the amount of organs available to each patient, thus saving many lives each year.
|Robert N. Ben (Credit : Ottawa University)|
Many lives worldwide are saved by organ transplants yearly. For an organ to be suitable for transplant the donor has to be biologically compatible with the patient, otherwise the transplant could cause an immune response and organ rejection. Because of the importance of a good match, often an organ has to be transported a long distance to reach the patient in need. Organs are usually transported coated in ice in order to slow down the biological processes and keep them fresh for transplant.
Cryopreservation is a process in which cells or tissues are preserved by cooling them to low sub-zero temperatures. Biological activity, including the mechanism that leads to cell death, is slowed down considerably during this process. However, this method may be dangerous to the cells and they are often damaged during cooling or warming. Researchers from the Ottawa University, led by Professor Robert N. Ben, found that ice crystals that form within the tissue during freezing caused the greatest damage to the tissues.
|Teleost Fish (Credit: United States|
Department of Agriculture)
Seeking a solution to this problem they looked at antifreeze glycoproteins (AFGPs) which are a type of biological chemical with an antifreeze function which are found in deep sea Teleost fish. These molecules lower the freezing point of the organism and enable it to survive subzero temperatures common in its environment. Professor Ben’s team synthesized a functional carbon-linked (C-linked) AFGP analogue. When the C-AFGPs are applied to the tissue, it reduces the formation of harmful ice crystals.
However, much research is still necessary before the synthetic compounds can be used to preserve organs meant for transplant. High concentrations of the substance were found to be toxic to the cells and the process by which the AFGPs prevent the formation of ice crystals is not well understood. The Ottawa team is currently running further experiments to understand the AFGP’s effect in full. They are seeking to develop AFGP’s analogues with increased stability of performance and low cytotoxicity. The ultimate goal is to understand the way AFGPs and the C-linked analogues are internalized within the cell, move around inside the cell, and finally assess whether any undesirable side effects occur during freezing.
TFOT has recently covered the story of the first known transplant patient to have switched their blood type
after the transplantation. We have also covered a gel-based vascular system
which can be used to create a scaffold for growing new tissues, developed at Cornell University.
For more information on the new freezing method please visit the ASL site
or Professor Ben’s research page