Preparation of Red Blood Cells Containing Exogenous Hemoglobin

A technique is described for opening the membrane of a red blood cell by electroporation in a manner which permits free exchange of the native hemoglobin with exogenous hemoglobin in the surrounding medium. After resealing the RBC's demonstrate near normal size and hemoglobin content and retain an effective methemoglobin reduction system. This method can be used to introduce natural or genetically engineered hemoglobins with altered oxygen binding characteristics. Allosteric effectors and other non-diffusible small molecules can be encapsulated during the same procedure. A fish Root effect hemoglobin exchanged into rat RBC's produced oxygen transport characteristics, unloading at high pressure at acidic pH, which should be useful to treat tissue hypoxia from a variety of causes.