Over the past few decades, there has been an increase in the development of new cellular therapies used for the treatment of various conditions. Thus, the rapid development of therapies requiring transfusion and transplantation of cells has resulted in a need to preserve these cellular therapy products. Cryopreservation is the only currently used method for the long-term storage of cells. The most commonly used cryoprotectants are 10% dimethyl sulfoxide (DMSO) for hematopoietic stem cells (HSCs) and 40% glycerol for red blood cells (RBCs). DMSO fails to protect the functionality of HSCs after cryopreservation and therefore, up to 20% of HSC transplantations fail to engraft. The glycerol in thawed RBC units must be removed to <1% to prevent intravascular hemolysis which is time-consuming. Thus, there is an urgent need to develop improved cryoprotectants for HSCs and RBCs.
DMSO and glycerol are unable to control ice recrystallization which is a major source of cellular injury during cryopreservation. Therefore, compounds with the ability to inhibit ice recrystallization could represent a new class of cryoprotectant with a novel mechanism of action.
This thesis focuses on the rational design of small-molecule ice recrystallization inhibitors. The key structural attributes required for ice recrystallization inhibition (IRI) activity are investigated. The amphiphilic balance required for IRI activity is explored. Furthermore, two new classes of small-molecule IRIs containing aromatic rings were rationally designed. As a result, several very highly IRI active molecules were discovered.
The use of IRIs to improve the cryopreservation of HSCs and RBCs was explored. A number of IRIs improved the post-thaw functionality of HSCs. Supplementation of the current cryoprotectant solution with IRIs resulted in an increase in CFU recovery and frequency of multipotent progenitors. This would reduce the percentage of engraftment failure and allow for a larger proportion of cord blood banks’ inventory to provide an adequate dose for patients requiring transplants. Several IRIs were found to be effective cryoprotectants for RBCs with reduced amounts of glycerol. This could reduce the deglycerolization time for RBCs. These results demonstrate the potential of small-molecule IRIs to improve the current cryopreservation procedures for important cellular therapy products.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/35005 |
| Date | January 2016 |
| Creators | Briard, Jennie Grace |
| Contributors | Ben, Robert |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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