Avoiding the Ice Cryolesion in Tissue Cryopreservation with Ice Modulators

The long term goal of the proposed research is to develop improved methods for cryopreservation of complex tissues at extreme low temperature. An innovative approach is taken in the proposed line of research, where synthetic ice modulators (SIMs) are combined with established cryoprotective agent (CPA) cocktails to create more favorable conditions for cryopreservation in a process known as vitrification. The application of SIMs enables lowering the CPA concentration, thereby reducing the toxicity potential, while decreasing the critical cooling and rewarming rates, thereby reducing the risk of structural destruction to the tissue as a consequence of thermo-mechanical stress. Lowering the toxicity potential together with moderating the thermal conditions required to facilitate vitrification represent a coupled barrier to the development of cryopreservation that this program aims to overcome by means of SIMs. Building upon baseline conditions for an ice-free and stress-free cryogenic protocol for cooling and warming 1 ml samples, the current project targets scale-up cryopreservation by increasing sample volume by 400% and 1000% respectively. Blood vessels will be used as key building blocks for cryopreservation applications in bulky tissues such as vascularized composite allografts, organs, and engineered tissue constructs. The objective is to retain at least 70% recovery of function.