In vivo O₂-transport of totally synthetic artificial red cell (lipid-heme-microsphere)

In vivo O₂-transporting ability of totally synthetic artificial red cell (lipid-heme-microsphere) is described. O₂-Binding affinity of the lipid-heme-microsphere (P( 1/2 )(O₂): ca. 40 Torr at 37°C was slightly lower than that of red cell (human blood) and its O₂-association and -dissociation rate constants were larger than those of hemoglobin. O₂-Solubility of the lipid-heme-microsphere dispersion was estimated. Highly O₂-dissolved aqueous solution can be prepared by the prescription of the lipid-heme-microsphere. The totally synthetic artificial red cell suspension was intravenously injected into hemorrhagic beagles (8 kg). Circulation life-time of each constituent of this system and O₂-consumption by the lipid-heme was determined. These results suggest that the lipid-heme-microsphere has an ability to act as an efficient O₂-carrier in blood stream.