Production and Characteristics of an Infusible Oxygen-carrying Fluid Based on Hemoglobin Intramolecularly Cross-linked with Sebacic Acid

Research on red cell substitutes requires the availability of oxygen-carrying fluids for physiologic experiments. This article describes the procedure for in-house production of such a fluid. It contains a hemoglobin-based oxygen carrier obtained by reacting human hemoglobin with bis-(3,5-dibromosalicyl) sebacate. This reagent produces intramolecular cross-links between the beta 82 lysines and between the alpha 99 lysines, respectively. The oxygen half-saturation pressure (P50) of the fluid is near 34 mm Hg at 37 degrees C, with a Hill's parameter of n = 2.2. The half-time of intravascular retention is near 3.0 hours in the rat and 6.5 hours in the cat. Spectrophotometric analyses of arterial and venous plasma from an infused rat reveal an efficient oxygen delivery to the tissues by the oxygen carrier. Therefore, this new cross-linked human hemoglobin can be produced in quantities sufficient for in vivo evaluation and with an oxygen affinity and cooperativity adequate for oxygen unloading in plasma.