American researchers froze pig kidneys to minus 150 degrees Celsius, then successfully thawed them and transplanted them into animals, infohub.kz reports.
Donor kidneys normally remain viable outside the body for no more than 36 hours, which leaves thousands of patients unable to receive the organ they need in time. A team at the University of Minnesota tackled the problem using vitrification, a process in which biological tissue is immersed in a cryoprotective solution and then frozen into a glass-like state in which ice does not destroy the cellular structure.
The main challenge of such freezing has always been warming the organ safely without damaging its tissue. To thaw the kidneys evenly, the specialists added iron oxide nanoparticles, which conduct heat and electricity, to the protective mixture. During thawing the particles were activated, allowing the organs to be brought gently back to room temperature.
After thawing and subsequent transplantation, the kidneys regained their natural color and immediately began producing urine. The scientists now hope to adapt the method for use with human donor organs, which would allow them to be stored in cryobanks for virtually unlimited periods.