Grant: Discovery Grants Program - Individual

Cell-based therapeutics has emerged as a critical aspect of modern healthcare in regenerative medicine and cell-based therapies. Unfortunately, current cryopreservation protocols remain suboptimal and limit the effectiveness of such therapies. Loss of cell viability after cryopreservation has been shown in fundamental and clinical studies to dramatically reduce potency of progenitor cells such as those used in hematopoietic stem cell (HSC) transplantation resulting in poor engraftment. Recent studies have indicated that the most significant cause of decreased post-thaw cell viability and ensuing function is the cellular damage from ice recrystallization during freezing and thawing. Unfortunately, conventional cryoprotectants such as dimethyl sulfoxide (DMSO) and glycerol do not protect against cellular injury from ice recrystallization and hence low post-thaw viabilities and poor functionality are observed. During the past decade, our laboratory has discovered a novel class of low molecular mass carbohydrate-based molecules that are very effective inhibitors of ice recrystallization. However, very little is know about how these molecules prevent ice recrystallization as well as their in vitro and in vivo interactions when they function as cryoprotectants. As part of our on-going program for the rational design of novel ice recrystallization inhibitors (IRIs) for the preservation of biological materials and cells, we will investigate the exact mechanisms by which this interesting class of molecules inhibit ice recrystallization and provide cryoprotection. This is an interdisciplinary program that has carbohydrate chemistry and organic synthesis at its core. The mechanism by which different classes of small molecule cryoprotectants inhibit ice recrystallization will be investigated through the design and synthesis of structural analogues followed by assessment for activity (classic medicinal chemistry approach). Investigating the cryoprotective mechanism of action will be performed using Human red blood cells and various progenitor cells as well as primary cells. Our laboratory has extensive experience in performing toxicity studies using in vitro assays (MTT, LDH etc.) as well as flow cytometry. Finally, to fully assess the nature of the cryoprotective mechanism(s), long term functional assessments will be performed using conventional methods of assessment (long term colony forming assays, glycomics, proteomics etc.). This comprehensive approach will allow us to better understand this novel class of cryoprotectants. In the long term, this research program will advance the field of cryobiology and enable many emerging cellular therapies as well as tissue engineering where the successful storage of products is urgently required. The fundamental knowledge learned from small molecule interactions with ice will also be applicable to many biological processes such as biomineralization.