Vita gazette – Scientists have achieved a significant milestone in brain preservation, bringing us closer to the possibility of eternal brain protection. In a groundbreaking experiment, cryogenically frozen brain tissue was successfully thawed in a laboratory environment, demonstrating resilience and functionality. This remarkable feat paves the way for potential advancements in neuroscience and cryogenics.

Brain tissue usually doesn’t survive freezing and thawing. However, that hasn’t stopped people from having their brains or entire bodies cryogenically frozen in the hope of being reanimated in the future. Researchers in China have successfully frozen and thawed human brain tissue, after which it regained normal function. Dr Zhicheng Shao and his colleagues at Fudan University in Shanghai, China, have successfully developed a solution to keep brain tissue alive while freezing it.

Professor Zhicheng Shao, a Harvard-educated neuroscientist at Fudan University in China, developed a complex chemical mixture called “MEDY” that protects neurons from freezing damage. “MEDY can be used for cryopreservation of human brain tissue,” said Dr. Shao in his study published in Cell Reports Methods.

The team used human embryonic stem cells to grow brain organoids – small clusters of self-organising brain cells – for three weeks, after which they developed into different types of brain cells. They then placed the organoids in various chemical compounds they hoped may help preserve the tissue while frozen in liquid nitrogen for at least 24 hours – including sugars and antifreeze. After thawing the samples, the team monitored them for growth and cell death over the next two weeks. Based on the most successful results, the researchers repeated the process using different combinations of the chemical compounds, eventually finding one that led to the most minor cell death and the most growth after thawing.

The winner is called ‘Medy’, short for the four compounds methylcellulose, ethylene glycol, DMSO and Y27632. Further testing of Medy revealed that the brain organoids continued to grow for up to 150 days after thawing, but the compound was also effective for use in freezing and thawing living brain tissue. The team tested 3-millimetre cubes of brain tissue removed from a 9-month-old girl with epilepsy and found they continued to remain active for at least two weeks after being thawed.

In Cell Reropts Methods, the team said: ‘Fresh, viable human brain tissue with natural, pathological features is a more reliable model to study neural diseases [than organoids].  ‘However, with limited accessibility and manipulability, cryopreservation and reconstruction of living brain tissue with specific pathological features remain hugely challenging, as it is hard to maintain the survival of large amounts of functional neurons. 

Speaking to Metro.co.uk’s sister publication, New Scientist, University of Birmingham professor Dr João Pedro Magalhães said he was impressed with the findings and the solution’s ability to prevent cell death and preserve function.

‘We know brain cells are very fragile and sensitive to stress,’ he said, adding that one day, the work could be ‘one small step’ towards freezing entire brains.

‘Thinking decades or centuries ahead, we can imagine patients being cryopreserved when they have a terminal condition or astronauts being cryopreserved to travel to other star systems,’ he said.

Although scientists have managed to freeze brain tissue without damaging it, freezing the whole brain is complicated and brings different problems.

If the experiments are successful, they could support future efforts to bring frozen people back to life.