STABILITY OF FROZEN AND DEHYDRATED CELLS AND MEMBRANES IN THE AMORPHOUS CARBOHYDRATE MATRICES - THE WILLIAMS-LANDEL-FERRY KINETICS

The kinetic stability of frozen and dehydrated cells and membranes in the amorphous state was examined. Dynamic processes examined included 1) membrane fusion and solute leakage of frozen liposomes and dry lipo somes in carbohydrate glasses, and 2) hemolysis and ice formation of f rozen human red blood cells during isothermal storage. The rate parame ters of these dynamic processes were Tg-dependent, deviated significan tly from the Arrhenius behaviors, and fitted the general form of the W LF equation well. The 'universal' values for C-1 (17.44) and C-2 (51.6 ) in the WLF equation did not apply to these dynamic processes. Howeve r, the derived values for C-1 and C-2 were generally in the same order of magnitude as the 'universal' values, and were process-dependent. T he reference temperature, To, in the general form of the WLF equation, was confirmed to be the T-g of the systems. The kinetics for hemolysi s of frozen blood cells was identical to that for solute leakage of dr y liposomes at ambient temperatures, probably because both hemolysis o f blood cells and solute leakage of dry liposomes were linked to the m embrane stability in the amorphous state, thus showing same kinetics. The results are discussed in relation to the prediction of the stabili ty of biological materials preserved in the amorphous matrix. At tempe ratures T > T-g, the stability of frozen and dehydrated cells and memb ranes decreased roughly at a rate of 10 ((T-Tg)/15), a factor of 10 ov er 15 degrees C at temperature T > T-g.