ABSTRACT
This chapter discusses the results concerning products obtained from polysaccharides and human hemoglobin (Hb). Two major problems associated with native Hb solutions are to be solved if they are to be widely accepted as oxygen-carrier fluids for transfusion purposes. The first limitation is represented by the insufficient intravascular persistence of free Hb, which leaks through the kidneys and the capillaries probably in the form of dimers. The second problem is caused by the absence of 2,3-diphosphoglycerate, the natural effector, which provokes too-tight binding of oxygen to Hb and makes the protein unsuitable for delivering enough oxygen to the tissues. The direct coupling of polysaccharides with native Hb does improve the intravascular persistence of the protein, as proved in many in vivo experiments, but does not allow a decrease in its oxygen affinity and further increases it. The tetrameric deoxyform of Hb was cross-linked and stabilized by reaction with a novel class of saccharidic reagents called conformation-specific stabilizers and cross-linkers.
