Scientists Have Finally Found a Way to Freeze Human Brains and Then ‘Thaw’ Them While Maintaining Normal Function.
This breakthrough was achieved by a research team led by Zhi Cheng Shao at Fudan University in Shanghai, China. Their new discovery could revolutionize the field of research on neurological diseases.
Frozen brain tissue successfully revived for the first time. (Photo: Adobe Stock).
Typically, brain tissue does not survive freezing or thawing. This has posed a significant barrier in medical research. To change this, the research team utilized human embryonic stem cells to develop organoids (clusters of cells that can grow and proliferate in a culture environment) over a period of three weeks.
This allowed for the development of neurons and neural stem cells. These stem cells can differentiate into various types of brain cells with different functions. Subsequently, the scientists placed these organoids—with an average diameter of 4 mm—into various chemical compounds such as sugar and antifreeze. This process aimed to identify which compounds could help preserve human brain tissue during freezing while still allowing growth after thawing.
After storing these organoids in liquid nitrogen for at least 24 hours, the research team thawed them and examined the dead cells or monitored the growth of neurons over the following two weeks.
Based on the rates of cell death and growth, the scientific team selected the most promising compounds, testing various combinations in freezing and thawing trials on new organoids.
The most successful combination included methylcellulose, ethylene glycol, DMSO, and Y27632, collectively known as MEDY. The scientists believe it will inhibit the factors that kill cells, allowing tissues to freeze and thaw without issues.
To test the effectiveness of MEDY, the research team conducted a series of experiments on brain organoids of various ages, ranging from 28 to over 100 days old.
They found that the thawed organoids retained a shape, development, and functionality similar to that of non-frozen organoids, even after being frozen in the MEDY compound for 18 months. Similar results were observed in frozen human brain tissue from different brain regions.
Thawed brain tissues illustrated through immunofluorescence staining technique (IF). (Photo: Weiwei Xue and colleagues).
Finally, the researchers obtained 3 mm-sized brain tissue blocks from a 9-month-old girl with epilepsy and placed them in MEDY, then froze and thawed them. This brain tissue maintained its structure prior to freezing and remained functional in the laboratory culture environment, lasting at least two weeks post-thaw.
According to researchers from the University of Surrey and the University of Birmingham in the UK, this breakthrough in freezing human brain tissue could enhance studies on brain development in laboratory settings, benefiting the health sector.
João Pedro Magalhães at the University of Birmingham expressed his admiration for the team’s method, which successfully prevented cell death and preserved their functionality. “We understand that brain cells are very fragile and sensitive to stress,” he stated.
Although this method still requires further research and the use of larger tissues, many are already predicting that the ultimate outcome will be the successful freezing of an entire human brain.
Some scientists envision a future where patients with terminal illnesses or astronauts traveling to distant star systems could have their brains cryogenically preserved. MEDY represents “a small step” toward that goal.
