This program deals with heat and mass transfer phenomena in the freezing of mammalian biological tissue and to provide a fundamental understanding of the thermophysical processes that occur during freezing of tissue. This study will be important to the development of methods for long-term storage of frozen organs, organs to be used for transplantation of other purposes. The method to be employed involves the correlation of the structure of the mammalian tissue after freezing to the perfusion treatments prior to freezing and the thermal history during freezing. Freezing and thawing will be performed under a range of controlled thermal conditions with a special "directional solidification: apparatus developed by the authors. The structure and chemical composition of samples will be assessed with Low-Temperature, Scanning Electron Microscopy, High Voltage Electron Microscopy, and X-Ray Microanalysis. As an outgrowth of a recent expedited award, the PI's will perfuse biological organs, specifically heart, kidney, and liver, with antifreeze glycopeptides, and study the role of this promising substance on the processes of tissue freezing. The experimental results will be used to develop mathematical models for the process of the freezing of tissue.
