Fluorochemical Emulsions for Biomedical Oxygen Transport

Transfusion with whole blood has several limitations and problems [38]. The storage stability of donated whole blood is limited. Blood must be stored at 4°C or frozen, but even under favorable conditions, the lifetime of refrigerated blood is only 5-6 weeks. Therefore, a blood reserve must be replenished continuously. It is not practical to build up a large blood reserve for an unforeseeable natural disaster or war because most of the stored blood would have to be discarded from time to time. 

An additional problem with transfusions of donated blood is the potential risk of transmitting bacterial or viral diseases, such as hepatitis or the human immunodeficiency (HIV) virus. Blood donors have to be carefully screened for their past and present diseases to reduce the risk of disease transmittal. 

Blood substitutes are needed for patients who refuse blood transfusion for religious reasons, in spite of their critical condition. 

There are differences and similarities between the two categories of blood substitutes. Hemoglobin or synthetic metal chelates combine oxygen chemically. 

Development of more concentrated injectable perfluorochemical emulsions has extended their diagnostic and therapeutic applications in medicine. Fluoro- 

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