A hydroxyethyl starch-hemoglobin polymer as a blood substitute

Mixtures of erythrocytes and acellular fluids: an in vitro evaluation

To evaluate the biophysical properties of two acellular resuscitative fluids, experiments were performed using mixtures of these with suspensions of red blood cells. Two acellular resuscitative fluids were synthesized using a diacid to tetramerically stabilized hemoglobin and then complexing it with either a hydroxyethyl starch or a Tetronic Polyol. The new polymers were characterized with respect to the molecular weight, second virial coefficient and intrinsic viscosity. These fluids were then combined with red cells and the following measurements were made: non-Newtonian flow properties, malonamide induced hemolytic kinetics, sedimentation rates and oxygen transport. The in vitro evaluation indicates that these compounds are effective hemodiluents, offer protection to the red cell membrane and do not cause erythrocyte aggregation. The oxygen transport was satisfactory.

A blood substitute from hydroxyethyl starch and hemoglobin

One method to increase the retention time of hemoglobin (Hgb) is to react it with a hydroxyethyl starch (HES) molecule. To examine this hypothesis, polymer-bound hemoglobin compounds were synthesized by the dialdehyde route. The electrophoretic mobility patterns indicate complete binding of the Hgb. Preliminary exchange-transfusion experiments in rates showed that they could survive for at least 10 h at Hct less than 10% when transfused with 6% HES-Hgb solutions. The retention time of the Hgb in the urine was increased to 12 h with these new polymers.