AsianScientist (Jan. 4, 2022) – While the immune system helps defend against disease-causing invaders, it can sometimes activate a rejection reaction against important organ transplants. Now, a team from South Korea has developed an artificial blood vessel platform to predict transplant rejection, detailing the invention in Science Advances.
Whether losing organ function to disease or injury, the high demand for organ transplants often outweighs the available supply from donors. Animal tissues like pig heart valves could potentially help address donor shortages, offering a lower cost option for medical interventions.
However, introducing such foreign objects may trigger an immune response, typically leading to blood clots, vessel blockage and destruction of the transplanted tissue. Scientists are designing animal organs with reduced risk of transplant rejection, but methods to evaluate their suitability are limited.
To this end, researchers from Korea Institute of Science and Technology (KIST), Seoul National University Hospital and Yonsei University developed a novel artificial blood vessel platform to simulate the human immune response to transplants.
The team poured liquid hydrogel into a tube-shaped mold of collagen and fibrin fibers, the main components of blood vessels. After solidifying, the artificial platform exhibited structural and physiological properties that were highly similar to the human circulatory system.
By creating a microenvironment that simulates blood flow and pressure, the innovation can help researchers visualize potential blood clots and assess the chances of a successful or failed transplant. The new approach also produced blood vessels in less than three days—much faster than existing cell culture methods that can take one to three weeks.
Through genetic modification, the researchers then engineered a pig blood vessel, testing it using mouse models and the artificial blood vessel platform with circulating human blood. In both cases, the changes made to the genes effectively suppressed the immune rejection response.
Besides showcasing the potential uses of pig blood vessels, the results highlight the value of the artificial blood vessel platform for anticipating unwanted immune responses to promote safe and successful transplants.
“The artificial blood vessel platform may be used as a preclinical tool for screening the new drugs and immunotherapy agents in corporations and hospitals, demonstrating potential for commercial utility,” said co-corresponding author Dr. Jung Youngmee from KIST.
The article can be found at: Kim et al. (2021) Tissue-engineered vascular microphysiological platform to study immune modulation of xenograft rejection.
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Source: Korea Institute of Science and Technology; Photo: Shutterstock.
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