Enter 2023.07.23 10:18 Modify 2023.07.23 09:58 Hit 24 Enter 2023.07.23 10:18 Modify 2023.07.23 09:58 Hit 24
In the United States, an experimental result was reported that the kidneys of frozen rats were thawed and transplanted, and they functioned normally. The possibility of ‘long-term freezing’ was identified. 《Science》, which is evaluated as one of the world’s most prestigious academic journals, introduced this content with the phrase ‘Life on hold’ on the cover of the 4th week of last month.
It is a bigger problem to thaw organs without damage than to freeze and store them. The technology of thawing while minimizing damage to cells using a cryoprotectant has become common. Eggs that are harvested during fertility and then frozen and stored are representative.
However, the dominant opinion in the academic world was that it was difficult to thaw in tissues or organs larger than cells. During the thawing process, if the melting speed of the inside and outside of the organ is different, the risk of damaging the organ due to the formation of water crystals due to the temperature difference is too great.
A research team at the University of Minnesota in the United States has solved this problem with ‘induction heating’ technology, which heats metal objects using electromagnetic field induction. Changing the magnetic field around a conductor, such as a metal, induces a current and applies heat to the metal. On the same principle, iron is distributed in the tissues at the level of very small nanodevices, and then the organs are thawed using a magnetic field.
This method can thaw the kidney in about 90 seconds, and the melting speed inside and outside the organ is uniform, preventing crystal formation and minimizing damage. The research team named this ‘Nanowarming’.
The research team rapidly frozen the kidneys of rats at minus 148 degrees Celsius and stored them for 100 days. Afterwards, the nano-thawed kidneys were transplanted into five mice, and the transplanted kidneys maintained their function for about 30 days. During the same period, mice also survived normally.
The results of this study have an important meaning in that ‘it has become possible to store organs for a long time’. Organ transplantation is known as a race against time, as organs are at high risk of decay over time after they are removed from the body. A kidney should be transplanted within 36 hours and a liver within 12 hours. The golden time for the heart and lungs is 6 to 8 hours.
The research team predicted, “If we succeed in applying the nano-thawing method to the human body, we can overcome the time constraints of organ transplanters.” Their explanation is that as the storage period increases to 100 days, spatial restrictions become virtually meaningless.
It was also interpreted that the results of this experiment confirmed the possibility of a ‘frozen man’ in the long run. Han Hyeong-tae, CEO of CrioAsia, who started the frozen human preservation business for the first time in Korea in 2020, said, “This study proves that frozen human technology is not a false story.
The research team said, “We will test the applicability of the nano-thawing method to the human body through additional research on other organs or other animals. We will first check whether the transplant recipient can survive for more than 30 days.” In the previous experiment, the mice that received kidney transplants were euthanized for histological examination after surviving 30 days.
