Heart on cryochip
For the first time, scientists have made heart tissue beat after freezing
Georgy Golovanov, Hi-tech+
When freezing tissues and organs for transplantation, it is important to prevent the dangerous formation of ice crystals. A new technology created by US scientists allows us to solve this problem. They were the first to successfully apply the cooling method to preserve and revitalize artificially created cardiac tissues. This means that in the future, donor organs may remain suitable for transplantation longer.
The technology proposed by specialists from the University of California at Berkeley is called isochoric cooling and was invented 16 years ago. It avoids the formation of ice crystals in the process of preserving biological material, and also begins to penetrate into the food industry, where it promises huge energy savings.
Whereas traditional isobaric cooling freezes the material under constant pressure in the air, isochoric cooling requires immersion in a liquid. Then the material is sealed in a strong container without access to air and excess space for the formation of ice crystals. In the past, scientists have already managed to cool samples to -22 °C and prevent freezing of 40% of the material, according to a press release from Cold-hearted science: Supercooling technique advances preservation of human tissue.
Article by Powell-Palm et al. Isochoric supercooled preservation and revival of human cardiac microtissues is published in the journal Communications Biology – VM.
Now researchers have developed a heart system on a chip by growing heart tissue from adult stem cells. These tissues contract in the same rhythm as the human heart, and microfluidic channels serve to supply nutrients and medicines. They immersed all this in an isochoric chamber and cooled it to -3°C. Then the samples were thawed after 24, 48 and 72 hours, heating them to +37 °C.
Spontaneous heartbeat was preserved in 65-80% of the samples, without a significant difference in the duration of cooling. The analysis of the material showed that the structural integrity of the tissues has not changed.
Also, the samples retained susceptibility to the drug isoproterenol, which increases the heart rate.
"As far as we know, this is the very first experience of cooling and restoring autonomously contracting, artificial human heart muscle," said study co–author Matt Powell-Palm.
Successful defrosting of heart tissues after three days of cooling is a promising proof of the effectiveness of the technology. It significantly increases the time of possible organ transplantation, which is now measured in hours.
From the editorial office:
a tiny slice and a whole organ are two very big differences, so transplantologists are unlikely to get such technology in the foreseeable future.
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