Genetically and chemically tuned haemoglobin-albumin trimers with superior O2 transport efficiency.

Haemoglobin (Hb)-albumin (HSA) trimers were synthesized using five distinct Hb variants in which the structures were genetically and chemically tuned as an artificial O2 carrier and used as a red blood cell (RBC) substitute. The trimers were found to have moderately low O2 affinity (p50 = 23-34 Torr, 37 °C) and high co-operativity, yielding a maximum O2 transport efficiency 1.8-fold higher than that of human RBCs.