The SmartBio System for the Improved Preservation of Human Hematopoietic Stem Cells

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Abstract The ultimate goal of cryopreservation (CP) is to develop a biobanking process that results in a post-thaw level of cell viability and function identical to a sister population that has not undergone preservation. Most methods used for the clinical level CP of human hematopoietic stem cells (hHSCs) and related stem cells, however, result in poor recovery due to post-thaw necrosis and apoptosis yielding an inferior cell product which is infused into patients. Given that over half or more of all stem cell products in clinical trials today, including hHSCs, are cryopreserved in 10% DMSO which is highly toxic, many studies have investigated ways to improve CP as well as alternative cryoprotective agents (CPAs) such as sugar alcohols to avoid the known toxicity and impact of DMSO on hHSC differentiation. Yet, to date no new hHSC CP process that eliminates DMSO has been developed commercially. CPSI Biotech hypothesizes that multiple milestones must be achieved to generate the best possible hHSC CP process to yield optimal outcome for the stem cell patient while minimizing or eliminating the requirement for DMSO. First, a unique high throughput freezing device must be developed so that hHSC-specific freezing profiles can be defined and executed. Second, DMSO must be replaced with agents that can prevent the formation and re-crystallization of lethal ice during the CP process. Third, a unique dry thaw system must be developed that will eliminate potential sample contamination, be amenable to documentation and most importantly can provide for hHSC-matched thaw profiles that can be achieved with a diverse array of biobanking vials and bags. Finally, a post-thaw recovery conditioning reagent and transfusion medium must be developed that can prevent post-thaw delayed onset cell death and improve engraftment of hHSC during transplant. This Phase II program is designed to address each of these milestones under the following specific aims: SA1a – Develop StemFreeze – a unique high throughput automated freezing system that has more operator and container flexibility than current systems such that hHSC-matched freezing profiles can be developed; SA1b - Develop StemThaw – a derivative of the SmartThaw system supported by the parent Phase I project that will be expressly designed for optimizing the thawing process of hHSCs and other stem cells resulting in improved post-thaw viability and function; SA2a - Develop StemCP - a non-toxic CPA cryo-cocktail containing Ice Recrystallization Inhibitors (IRIs) to replace DMSO which can be added to any carrier medium of choice to improve CP of hHSCs in the absence of DMSO; SA2b - Formulate StemRevive and StemInfusion – a first in class post-thaw conditioning reagent and dilution media designed to ameliorate post-thaw apoptosis/necrosis increasing stem cell transfusion efficacy and SA3 – Evaluate the stem cell specific SmartBio platform for optimized CP of HSCs in vitro and in vivo. Collectively this multicomponent system will comprise a stem cell specific product line under CPSI’s SmartBio platform. In summary, CPSI hypothesizes that addressing all five challenges together will streamline the biobanking process and move the hHSC CP sciences closer to the ultimate milestone of achieving a cryopreserved product that is equivalent to non-frozen hHSCs. This achievement will result in improved outcome for patients receiving stem cell transplants.