Cross-linked stroma-free polyhemoglobin as a potential blood substitute.

Stroma-free hemoglobin is prepared from human blood and then cross-linked with glutaraldehyde to produce soluble polyhemoglobin. Results from animal studies show that in the case of polyhemoglobin, its level in the circulation remained unchanged at 77% of the injected amount when followed for 3 hours; whereas stroma-free hemoglobin was removed rapidly with a half-life of 87 minutes. Thus, cross-linking stroma-free hemoglobin into the polyhemoglobin form has solved the major problem of rapid removal of stroma-free hemoglobin from the circulation.