HUMAN RED BLOOD CELL FREEZING WITH AND WITHOUT METABOLIZABLE CRYOPRESERVATIVES MOLECULAR DISTILLATION DRYING STORAGE AND...

A GOAL OF ERYTHROCYTE HYPOTHERMIC PRESERVATION IS TO DEVELOP A NONTOXIC, METABOLIZABLE CRYOPROTECTANT TO DECREASE THE INHERENT CYTOTOXICITY AND TO MINIMIZE OR ELIMINATE THE COSTLY AND TIME CONSUMING CELL WASHING PROCEDURES POSTTHAW. WE PROPOSE THAT CRYOPROTECTANTS BE ELIMINATED OR USED AT MINIMAL CONCENTRATIONS BY VITRIFYING (FREEZING WITHOUT ICE CRYSTALS) RED CELLS BY ULTRARAPID COOLING, AND THEN BY ELIMINATING THE AMORPHOUS PHASE WATER BY MOLECULAR DISTILLATION DRYING AT 10 MINUS 8 MBAR VACUUM WITH SLOW PROGRAMMED TEMPERATURE INCREASES TO YIELD DRY, ROOM TEMPERATURE RED CELLS SUITABLE FOR REHYDRATION AND TRANSFUSION. EXPERIMENTS WILL BE UNDERTAKEN TO DETERMINE THE OPTIMUM METHOD OF CELL VITRIFICATION AND WHETHER CRYOPROTECTION AND DRYING PROTECTION IS NEEDED, WHETHER UNIFORMITY OF MEMBRANE COMPOSITION CAN BE MAINTAINED AND OSMOTIC STRESS MINIMIZED, AND WHETHER PRESTRESSING THE CELLS THERMALLY OR OSMOTICALLY MIGHT AID THEIR ABILITY TO SURVIVE DRYING. ALTERNATIVE PRESERVATION CONDITIONS WILL BE TESTED, AND THEN THE MORPHOLOGY AND STRUCTURE OF THE CELLS WILL BE DETERMINED BY LIGHT MICROSCOPY AND TRANSMISSION ELECTRON MICROSCOPY OF WHOLE SAMPLES AND SCANNING ELECTRON MICROSCOPY OF WHOLE AND FREEZE-FRACTURED SAMPLES. TESTS WILL ALSO BE MADE OF MEMBRANE INTEGRITY AND BIOCHEMICAL FUNCTIONALITY OF THE CELLS POSTPRESERVATION.