Researchers at Texas A&M University report that raising the glass-transition temperature of aqueous vitrification solutions can reduce thermal-stress cracking—one of the key barriers to long-term cryopreservation of larger tissues and, eventually, transplant organs.
Researchers at Texas A&M University say they have identified a major thermodynamic variable that can help reduce cracking during cryopreservation—fractures that can render larger tissues and organs unusable after ultra-cold storage.
In a study published in Scientific Reports, the team reports that higher glass-transition temperatures in aqueous vitrification solutions are associated with a lower likelihood of thermal-stress cracking during cooling.
Vitrification is an ice-free preservation approach that cools biological tissue in a cryoprotective solution until it enters a glass-like state, helping avoid ice-crystal formation that can damage cells. But cracking remains a persistent challenge, especially as sample sizes increase, because rapid temperature changes can create mechanical stresses.
"In this study, we investigated different glass transition temperatures, which we believe play a dominant role in cracking," said Matthew Powell-Palm, an assistant professor in Texas A&M’s J. Mike Walker ’66 Department of Mechanical Engineering. "We learned that higher glass transition temperatures reduce the likelihood of cracking."
Powell-Palm also cautioned that preventing fractures is not the only requirement for viable preservation.
"Cracking is only one part of the problem," he said. "The solutions need to be biocompatible with the tissue as well."
The ScienceDaily release describing the work frames the findings as a step toward the longer-term goal of “banking” organs for later use, and it points to prior progress in the field. In 2023, researchers at the University of Minnesota reported a life-sustaining rat kidney transplant after the organ was cryopreserved and rewarmed.
Co-author Guillermo Aguilar, identified as head of Texas A&M’s Mechanical Engineering Department and the James and Ada Forsyth Professor, called the study a foundational step for future work.
"This study offers a seminal contribution to our understanding of aqueous solution thermodynamics," Aguilar said, adding that he expects progress that "will ultimately yield an increased viability of biological systems of all scales -- from single cells to whole organs."
Texas A&M said the study also involved Soheil Kavian, Ph.D. students Crystal Alvarez and Ron Sellers, and undergraduate student Gabriel Arismendi Sanchez.
Funding was provided through the National Science Foundation’s Engineering Research Center for Advanced Technologies for the Preservation of Biological Systems, according to the release.
Beyond transplantation research, the release noted that improved cryopreservation methods could have applications in biodiversity conservation and vaccine storage.