Surface modification of diaspirin cross-linked hemoglobin (DCLHb) with chondroitin-4-sulfate derivatives. Part 1

Synthetic methodology was developed for the preparation of chondrotin-4-sulfate reagents that could be specifically attached to the surface of diaspirin cross-linked hemoglobin (DCLHb), a chemically stabilized human hemoglobin. The surface-modified hemoglobin solutions had a significantly higher colloidal osmotic pressures (COP) than DCLHb. The P(50) of the modified DCLHb was dependent upon the reactive end group of the chondrotin-4-sulfate reagents that was used for the protein modification. Modification of DCLHb with the chondroitin-4-sulfate derivatives containing the maleimide end group 23 provided a hemoglobin with a P(50) value of 23 mmHg, while the P(50) of hemoglobins prepared from chondroitin-4-sulfate derivatives containing the aldehyde end group 13 and 18 remained unchanged from that of DCLHb.