Artificial Blood Alternatives

Universal blood substitution has been stumping scientists globally for many years. Currently, the only clinically approved method in replacing lost blood is a red blood cell (RBC) transfusion from a human donor, which requires matching blood types. Located within each RBC is the protein, hemoglobin. Hemoglobin is a tetrameric protein that consists of two α and two β polypeptide chain subunits and a prosthetic functional heme group whose function is to reversibly bind oxygen molecules. Most research for oxygen carrying alternatives have been based on this hemoglobin molecule and are known as hemoglobin-based oxygen carriers (HBOCs). HBOCs are universally compatible for all blood types. All of the past attempts at producing a clinically acceptable HBOC have fallen short due to stabilization techniques that impeded normal physiological functionality and led to major toxic side reactions. The goal for this Honors Thesis is to load cell-free hemoglobin into polyelectrolyte complexes, known as coacervates, in order to promote protein stability and keep cell-free hemoglobin in its tetrameric form. Upon optimizing the stoichiometry of these polyelectrolyte complexes to maximize the loading volume of hemoglobin, tests on overall protein stability, shelf-life, and oxygen transport will be performed. With these results, the efficacy of hemoglobin encapsulation via complex coacervation will be determined. Although in vitro oxygen transport tests in physiologically equivalent solutions need to be completed in order to conclude the efficacy of this method, any advancement in this field of oxygen carrying alternatives is critical for accentuating the most feasible solution.