In a secluded laboratory on the 11th floor of the University of Minnesota’s Malcolm Moos Health Sciences Tower, a crucial experiment took place. From the abdomen of a lab rat, a kidney had been harvested, filled with black fluid, frozen to –150°C, and vibrated with a potent magnet. Hours later, it was gently positioned in another rat's abdomen. On its reconnection to the host's blood vessels, the kidney flashed a rosy pink signifying vitality and soon started producing golden droplets of urine.

The successful transplantation of the vitrified, nano-warmed rat kidney, achieved by surgeon-in-training Rao, was a milestone in the medical field, promising to revolutionize organ transplants by halting biological decay using extreme cold. This success followed decades of scientific endeavors to counteract the toxic effects of chemical antifreeze treatments and the formation of destructive ice crystals. Scientists now have tools to bring back to life previously frozen specimens, including coral fragments, zebrafish embryos, and rat kidneys.

The potential of this technique is immense, especially in the realm of organ transplantation. The creation of cryopreserved banks of organs, tissues, or limbs could alleviate organ shortages and offer doctors time to better prepare recipients for transplants. But it goes beyond that. From human tissue samples used for pharmaceutical research to endangered species, the method offers a new way to store and preserve biological material. Mehmet Toner, a leading bioengineer in the field, visualizes a time when living tissues could be stored and made available on demand - a "biological Amazon", so to speak.

Persistence in this domain is underpinned by a crucial reality: organ decay is one of the major obstacles in transplant procedures. Once detached from the donor, organs have a limited time before they become irretrievably damaged. This timeline places an enormous burden on the medical system and the patients. Cryopreservation could extend this timeline indefinitely, allowing organs to be stored until they are needed and improving the chances of an immunological match between the organ and the recipient.

Sebastian Giwa, founder of the Organ Preservation Alliance, believes that the impact of cryopreservation could be transformative for biomedicine. By developing technologies for vitrifying organs, his team is taking pioneering steps towards making organ transplantation less burdensome and more successful. In collaboration with companies like GaiaLife, they are experimenting with ovaries, with the aim of vitrifying these organs before ovary-damaging treatments like chemotherapy and then reimplanting them afterward.

These scientific strides do face challenges. Vitrifying, or solidifying organs without crystallization, is only the first step. Equally important is the development of techniques to rewarm these organs rapidly and evenly, a hurdle that teams worldwide are working on. Different strategies, from nano-warming with iron particles to utilizing a fine metal mesh engineered for temperature transmission, are being tried and tested with varying degrees of success.

The aim is to redefine the limits of what we can preserve

The quest is not just to extend the viability of organs, but to redefine the limits of what we can preserve. The innovations coming out of the field, like storing human livers at sub-zero temperatures or supercooling organs without damage, are pushing the boundaries of what we thought possible. Though it's still a work in progress, the researchers are hopeful that these technologies can be translated to other areas as well, from preserving the biodiversity of coral reefs to revolutionizing the food industry.

While the vision of having readily available, preserved human organs for transplantation may seem like science fiction, the rapid strides being made in the field of cryopreservation are turning it into an imminent reality. It has the potential to transform the field of medicine and redefine how we approach biological preservation, making the once unthinkable prospect of halting biological time a tangible goal.

Reference

●      Cornwall, W. (2023). "Frozen In Time." Science, Vol 380, Issue 6652. Available at- https://www.science.org/content/article/how-to-deep-freeze-entire-organ-bring-it-back-to-life