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Date Permissions Signed


Date of Award

Spring 2022

Document Type

Masters Thesis

Department or Program Affiliation


Degree Name

Master of Science (MS)



First Advisor

Anthony-Cahill, Spencer J.

Second Advisor

Antos, John M.

Third Advisor

Amacher, Jeanine


Our work with hemoglobin-based oxygen carriers (HBOCs) is focused on developing a hemoglobin (Hb) polymer that can be used as a blood replacement in critical care at an affordable cost. For medical use, the Hb must be polymeric since cell-free Hb has multiple adverse side effects when it is not encapsulated in a red blood cell. These include kidney damage and heme-induced toxicity, which is due to cell-free Hb’s ability to extravasate. Challenges in making HBOCs, that have been observed in the past, are low protein expression yields and heterogeneity in polymeric Hb products produced by chemical crosslinking. In conducting this research, we have two strategies to create a monodisperse high molecular weight HBOC. The first of these strategies uses sortase-mediated ligation (SML) to introduce a chemical modification to the Hb monomer, followed by reaction of the modified Hb with a scaffold molecule that has a specific number of sites that can react with the modified Hb by so-called “click chemistry”. The second strategy involves fusing the gene for Hb to a so-called “circular tandem repeat protein” (cTRP). The cTRP protein is known to self-assemble into a tetrameric structure1. Thus, we plan to use the cTRP protein to drive the spontaneous formation of the polymeric Hb. This work is an important contribution to biomedical research due to the potential for significant clinical benefits. Clinical trials have been performed with HBOCs, but the FDA has not yet approved any of them for human therapeutic use due to many challenges associated with current means of producing Hb polymers2. Our research aims to address the challenge of making well-defined Hb polymers that can improve the clinical success of HBOCs for therapeutic use.




Western Washington University

OCLC Number


Subject – LCSH

Blood--Transfusion; Hemoglobin; Oxygen--Physiological transport; Polymers; Protein engineering; Amino acid sequence; Staphylococcus aureus




Academic theses




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