ABSTRACT
For several decades a wide variety of strategies have been investigated for the
replacement of stored red blood cells (RBCs) by “blood substitutes.” Currently
the most common method is the use of volume expanders, such as hetastarch,
but this does not directly address tissue oxygen requirements. Purified hemo
globin solutions, both encapsulated and acellular, and perfiuorocarbons have
been developed to deliver oxygen. Hemoglobin-based oxygen carriers
(HBOCs), which are made from acellular hemoglobin, are close to commercial
ization because of the combination of their ability to transport a large amount
of oxygen when compared to perfiuorocarbons and their relative ease of pro
duction when compared to encapsulated hemoglobin. With the emergence of
sophisticated purification technologies and understanding of the modifications
necessary to eliminate side effects, great strides have recently been made in the
field. Furthermore, pharmacological and physiological studies have identified a
more efficient oxygen therapy role for HBOCs compared to RBC hemoglobin.
