A New Device and Technique for Thermal Conductivity Measurements of Glass-Forming Materials With Application to Cryopreservation

The current study is aimed at developing a device and technique to measure the thermal conductivity of materials relevant to cryopreservation — the preservation of biomaterials at very low temperatures. It is well established that ice formation is the cornerstone of low-temperature injury [1]. In an effort to improve the outcome of cryopreservation, ice crystallization can be controlled by the addition of cryoprotective agents (CPAs), such as dimethyl sulfoxide (DMSO). CPA solutions are characterized by exponentially increasing viscosity with the decreasing temperature. If cooled rapidly enough, the crystalline phase can be completely suppressed and the material is trapped in a solid-like state known as vitrification (vitreous in Latin means glassy). While correlating the quality of the cryopreserved product with the thermal history may be straightforward to obtain in small specimens, characterized by close-to-uniform temperature distribution, analysis of larger specimens requires integration of mathematical tools to estimate the spatial temperature distribution at any instant along the cryogenic protocol. The data developed in the current study is aimed at enabling the corresponding thermal analysis, while exploring the variation in thermal conductivity between the crystalline and glassy states.