Cryopreservation through vitrification; the process of cooling biological tissues into a glass-like state has long been seen as a potential solution for preserving organs, vaccines, and other biological materials. While this approach avoids the damaging ice crystal formation that occurs during conventional freezing, scaling vitrification from small samples to whole organs remains a major challenge. A key issue is that organs can crack during the extreme cooling or rewarming processes, compromising their viability.
Researchers from the J. Mike Walker ’66 Department of Mechanical Engineering at Texas A&M University, led by Dr. Matthew Powell-Palm have recently highlighted the role of the glass transition temperature, or T₉, in determining whether cracks form. The team, led by mechanical engineers Matthew J. Powell-Palm and Guillermo Aguilar, investigated aqueous vitrification solutions across a wide range of T₉ values and observed the relationship between glass transition behavior and mechanical stability under cooling. By employing a specialized imaging system alongside computational modeling, they were able to directly track when and how cracks emerge as thermal stresses build. Their findings, suggest that solutions with higher T₉ values are significantly less prone to cracking.
Kavian, S., Sellers, R., Sanchez, G. A., Alvarez, C., Aguilar, G., & Powell-Palm, M. J. (2025). Higher glass transition temperatures reduce thermal stress cracking in aqueous solutions relevant to cryopreservation. Scientific Reports, 15(1), 27903. https://doi.org/10.1038/s41598-025-13295-7
The reasoning lies in the thermomechanical properties of these solutions. Materials with higher glass transition temperatures tend to contract more uniformly and exhibit lower thermal expansion mismatches during cooling. This reduces the internal stresses that otherwise drive fractures through the vitrified medium. While other factors such as sample geometry, boundary conditions, and cooling rates still play a role, the study identifies T₉ as an underused lever in cryopreservation design.
Researchers Dr. Matthew Powell-Palm from Texas A&M University stated,
“In this study, we investigated different glass transition temperatures, which we believe play a dominant role in cracking. We learned that higher glass transition temperatures reduce the likelihood of cracking.”
These results resonate with broader efforts in the field. Other groups have been developing nanowarming strategies, which rely on distributing nanoparticles through tissues and heating them with electromagnetic fields to achieve uniform rewarming. Such methods directly address uneven temperature distribution, another source of cracking and failure. Until now, however, vitrification research has focused heavily on ice suppression and cryoprotectant toxicity, while the specific thermophysical tuning of glass transition temperatures has received less attention. The Texas A&M findings broaden the design space for cryoprotective solutions and suggest that higher T₉ mixtures could improve the safety margin for large-scale organ storage.
The implications for engineering cryopreservation systems are considerable. If cryoprotectant formulations can be optimized for higher glass transition temperatures while maintaining biocompatibility, then both cooling and rewarming become less constrained by stress-related damage. This could make preservation protocols more robust, particularly for organs where nonuniform conditions are unavoidable. The challenge, of course, lies in finding or engineering mixtures that raise T₉ without introducing harmful levels of toxicity or osmotic stress, and in integrating these advances with hardware capable of delivering uniform cooling and warming at scale.
Unresolved questions remain. The behavior of vitrified solutions during rewarming may differ from their cooling performance, and cracking induced during warming continues to limit the reliability of organ preservation. Scaling laboratory experiments to the volumes and geometries of human organs also introduces additional complexity, and biocompatibility must remain a central consideration alongside thermomechanical performance.
Even with these open challenges, the new work reframes how engineers might think about vitrification chemistry. By linking glass transition temperatures directly to fracture resistance, it offers a practical parameter for guiding the design of cryoprotectant formulations. For a field that aims to make long-term organ banking and reliable biological storage a reality, the identification of T₉ as a critical variable could represent an important step forward.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
