Lyophilized hemoglobin-albumin cluster with disaccharides: Long-term storable powder of artificial O-2-carrier

Core-shell protein cluster comprising a hemoglobin (Hb) in the center and human serum albumins (HSA) at the exterior, Hb-HSA( 3) cluster, is an artificial O-2-carrier designed for use as a red blood cell (RBC) substitute. Lyophilization of the Hb-HSA( 3) cluster solution ([Hb unit] = 5 g/dL) with sucrose and trehalose yielded stable pink powder, which can be stored for 2 years at 4 degrees C. Addition of pure water to the powder regenerated the homogeneous solution. The O-2-binding properties and oxyHb rate have been unaltered during the storage period. Infrared spectroscopic studies revealed that the hydrogen bond between protein and sugar stabilizes three-dimensional structure of the cluster.