Ice Recrystallization Inhibition as a Mechanism for Reducing Cryopreservation Injury in a Hematopoietic Stem Cell Model

Abstract

Cryopresevation is the process of cooling biological materials to low sub-zero temperatures for storage purposes. Numerous medical and technical applications, such as hematopoeitic stem cell transplantation and sperm banking, sometimes require the use of cryopreserved cells. Cryopreservation, however, can induce cell injury and reduce the yields of viable functional cells. Ice recrystallization is a mechanism of cryopreservation injury, but is rarely addressd in strategies to optimize cell cryopreservation. The results from this thesis demonstrate an association between the potency of carbohydrate-mediated ice recrystallization inhibition used in the cryopreservation of umbilical cord blood and recovery of viable non-apoptotic cells and hematopoietic progenitor function. Furthermore, increased numbers of apoptotic cells in hematopoeitic stem cell grafts were associated with reduced hematopoietic function and delayed hematopoietic recovery in patients undergoing blood stem cell transplantation. These findings provide a basis for pursuing further studies assessing ice recrystallization inhibition as a strategy for improving cell cryopreservation.