Can thermal expansion differences between cryopreserved tissue and cryoprotective agents alone cause cracking?

One of the limiting factors in large-scale cryopreservation is the formation of fractures. The prevalence of cracking in cryopreserved bulky tissues is frequently associated with temperature gradients, which lead to non-uniform thermal contraction of the tissue. With new cryoprotectants available, it may be possible to reduce temperature gradients to much lower levels, in which case other contributions to mechanical stress development and cracking will become more significant.

Viscosity of cryoprotective agents near glass transition: a new device, technique, and data on DMSO, DP6, and VS55.

The low strain-rate viscosity of glass-forming cryoprotective agents (CPAs) in the vicinity of the glass transition is studied experimentally. Data on the mechanical behavior in this regime is necessary to the long-term goal of developing planning tools for cryopreservation via vitrification (vitreous means glassy in Latin); such tools will provide guidelines for reducing thermal stress with its devastating effects. While the flow behavior of some glass-forming CPAs is well documented in the literature for the upper part of the cryogenic temperature range (where the CPA has a comparatively low viscosity), it is the flow behavior near the glass transition temperature (where the CPA behaves as nearly a solid with an extremely high viscosity) which is critical to the analysis of stress that develops in the cryopreserved material.