There is a growing level of interest and funding for the goal of reversible cryopreservation of whole organs. If achieved, this would radically improve the logistics of organ donation, allowing organs to be kept indefinitely before use. Proof of principle demonstrations have been carried out, but the field has lacked the funding and impetus to rapidly build upon that starting point. Hopefully this will change. The ability to reliably vitrify and thaw large tissue sections with minimal ice crystal formation, cell death, or other structural damage will add legitimacy to the goal of human cryopreservation, storing patients at the time of death to allow the possibility of future revival in an environment of far more capable biotechnology.
When scientists in the 1950s tried to cool hamsters to 0°C and rewarm them, it didn't go great. In 2002, things looked rosier when a scientist chilled a single rabbit kidney down to -130°C, then rewarmed it and transplanted it into a live rabbit, where it worked for 48 days. Then not much else succeeded for the next decade. Chilling and re-warming organs, it turns out, is really, really hard. Ice crystals that form during cooling and re-warming cause massive physical damage to cells and whole tissues.
To nudge the field forward, in 2014 a group of entrepreneurs formed the nonprofit Organ Preservation Alliance (OPA). In the years since, the OPA coordinated numerous conferences and publications and prompted the creation of a National Science Foundation technology roadmap for organ cryopreservation, all of which bolstered more than $100 million in new cryobiology funding from U.S. science agencies, donors, and industry. Now, in what OPA sees as a culmination of their efforts, the organization is launching a philanthropic fund to support two academic research centers focused on cryopreservation. "It's been a renaissance for the field of cryobiology. These two centers build on that momentum, and new technologies have come into sharp focus within the same timeframe."
Resarchers will focus on safely cooling tissues and organs by infusing the vasculature and surroundings with cryoprotective solutions and iron oxide nanoparticles coated with silica. After rapid cooling to a very low temperature, a process called vitrification, the organ or tissue is stored. Upon rewarming, the team activates the distributed nanoparticles via a radiofrequency field, heating the cryopreserved tissue rapidly and uniformly. Finally, the cryoprotective agents and nanoparticles can be safely removed prior to transplant or other biomedical use. "Scientists are coming back to ideas they had in the 1980s, but now with the right technology to carry them out. It's incredibly exciting. Back then, we didn't have the right tools, but now it feels like we really do. We hope we're about to make this really big step forward."