Stable preservation of hemoglobin vesicles as a blood substitute

Long-term preservation of hemoglobin (Hb) vesicles, the so-called artificia l red cell (ARC), in dry powder was studied. Carbonylhemoglobin (COHb) was encapsulated in the vesicle of 1,2-bis(2,4-octadecadienoyl)-sn-glycero-3-ph osphocholine (DODPC) and the polymerizable membrane components were polymer ized by gamma-ray irradiation. The obtained ARC suspension was then freeze- dried in the presence of sucrose. The factors influencing the shelf-life of the freeze-dried ARC, such as sucrose concentration, moisture and storage temperature, were elucidated. After storage in the dry state for more than one year, the oxygen-carrying capacity was recovered by rehydration of the freeze-dried ARC with distilled water and substitution of the carbon monoxi de ligand with oxygen. Copyright (C) 1999 John Wiley & Sons, Ltd.