OXYGEN-CARRYING BLOOD SUBSTITUTES

Transfusion of human blood components still has major drawbacks, such as transfusion-transmitted diseases, requirements for blood type analy sis and cross-match testing, availability and supply, storage and pres ervation time. The rapid progress in science and technology has advanc ed to a critical stage where safe and effective alternatives to the tr ansfusion of red blood cells emerge. Although some toxicity issues rem ain, substantial improvements in the area of artificial oxygen carrier s have been made in the past years. To date hemoglobin- and perfluoroc arbon-based oxygen carriers are under clinical investigation. In addit ion to their use as red blood cell substitutes other clinical applicat ions of artificial oxygen carriers should be considered. Due to their physiological properties (especially acellular oxygen transport) artif icial oxygen-carrying solutions can be used to provide oxygen to ische mic tissues which cannot be reached by cellular blood components. Long er preservation times of organs awaiting transplantation have been des cribed after perfusion with artificial oxygen carriers as well as an i ncrease in tumor susceptibility to chemo- and radiotherapy. Therefore, artificial oxygen carriers are not only confined to their use as red blood cell substitutes, but will find a wide and divergent spectrum of interdisciplinary applications. Since blood transfusion is a big busi ness and enormous amounts of capital have been invested in the search of artificial oxygen carriers, it can be assumed that substitutes of r ed blood cells will be available during the next years. However, since there is no anticipated substitute for all fractions of human blood, there will be an ongoing requirement for human blood components, such as fresh frozen plasma, platelets, and others.