Dana Dahhan

Year: Junior

Major(s):  Biochemistry

Mentor: Olsen, Ken

Department: Chemistry & Biochemistry

Project Title: Creation of a hemoglobin-based oxygen carrier using the novel approach of “inside-out” PEGylation

Project Abstract: The great demand for blood transfusions has led researchers to investigate hemoglobin-based oxygen carriers (HBOCs) made from modifications of whole bovine blood. It is necessary for these HBOCs to not only be immunogenic and sterile, but to also avoid vasoconstriction, redox chemistry, and dissociation of the hemoglobin (Hb) tetramer while maintaining an increased oxygen affinity. Such a HBOC can be made from extracting and modifying the hemoglobin from bovine red blood cells. To prevent dissociation of the Hb tetramer into αβ dimers upon circulation in the human body, the HBOC is crosslinked with DBSF on the lysine residues of the Hb’s beta chains. Redox chemistry and vasoconstriction are reduced by increasing the size of the HBOC. The Olsen lab has developed a novel approach to increasing the volume by “inside-out” PEGylation, a method which binds eight Hb tetramers to one extension-arm facilitated polyethylene glycol backbone. The Olsen HBOC will be purified and characterized. Many methods (SDS-PAGE, filtration by centrifugation, anion-exchange columns, UV-Vis absorption spectroscopy) will be used to confirm the success of the purification, crosslinking, and PEGylation reactions. Oxygen binding analysis will also be performed on the HBOC.