SusCHEM: Fundamental Studies on Lyopreservation of Adult Stem Cells

1605425 何晓明 活细胞在常温下以假死状态冷冻保存银行，可以实现细胞的低成本维护和便捷的流通。 细胞的现成可用性对于细胞疗法的广泛应用和最终成功至关重要，这些疗法涉及组织工程、再生医学、细胞移植、输血和干细胞疗法。该项目的目的是进行系统研究，以了解海藻糖（一种无毒糖）在冷冻和干燥富含海藻糖的人类脂肪干细胞 (hADSC) 期间以及在环境温度下储存干燥细胞时的保护作用。由于海藻糖已被用于许多低等生物体以在自然界的极端寒冷和干旱中生存，因此假设负载海藻糖的干细胞也会表现出类似的行为。 该项目将促进细胞冻存技术的发展，作为细胞医学治疗成功的支持技术，从而对改善医疗保健产生重大影响。使用无毒糖（海藻糖）替代细胞库中的有毒化学物质（例如二甲亚砜或 DMSO）与 NSF SusCHEM 倡议非常一致，即用地球上丰富、廉价且良性的材料替代有毒化学物质。为了了解在环境温度下以假死状态干燥活细胞以进行储存的基础科学，提出了三项具体的研究任务。这些包括（i）分别使用冷冻干燥显微镜和台式冷冻干燥机研究小样本和大样本的冷冻干燥参数对海藻糖溶液干燥动力学和干燥产品微​​观形态的影响，海藻糖溶液对于原代 hADSC 的冷冻保存很重要； (ii) 载有海藻糖的 hADSC 对冷冻和干燥的生物物理反应的模拟和实验量化，包括细胞脱水和对细胞生存重要的细胞内冰形成； (iii) 冷冻干燥并在环境温度下保存后，对原代 hADSC 的形态、存活、长期增殖以及干细胞特性和功能进行分析。干细胞的特性和功能将通过干细胞基因和蛋白质标记的表达及其成脂、成骨和软骨分化的能力来评估。在最佳条件下冷冻干燥和在环境温度下长期储存后，预计原代 hADSC 具有高存活率和完整功能。该奖项由 CBET 部门生物技术和生化工程项目获得，并由材料研究部门生物材料项目共同赞助。

1605425 He, Xiaoming Lyopreservation of living cells for banking in a state of suspended animation at ambient temperature makes it possible to achieve low-cost maintenance and convenient distribution of the cells. The ready availability of cells is crucial for the wide application and eventual success of cell-based therapies involving tissue engineering, regenerative medicine, cell transplantation, blood transfusion, and stem cell therapy. The objective of this project is to perform a systematic investigation to understand the protective effect of trehalose, a nontoxic sugar, during freezing and drying of trehalose-laden human adipose-derived stem cells (hADSCs) and in banking the dried cells at ambient temperature. As trehalose has been used for many lower organisms to survive extreme cold and drought in nature, it is hypothesized that trehalose-laden stem cells will behave similarly. This project will have a significant impact on improving healthcare by facilitating the development of cell lyopreservation as an enabling technology for the success of cell-based medical treatments. The use of a nontoxic sugar (trehalose) to replace toxic chemicals (e.g., dimethyl sulfoxide or DMSO) for cell banking is well aligned with the NSF SusCHEM initiative to replace toxic chemicals with earth-abundant, inexpensive, and benign materials. To understand the fundamental science of drying living cells for banking in a state of suspended animation at ambient temperature, three specific research tasks are proposed. These include (i) investigation of the effect of freeze-drying parameters on the kinetics of drying trehalose solutions important for lyopreservation of primary hADSCs and on the microscopic morphology of the dried products, using freeze-drying microscopy and a benchtop freeze-dryer for small and large samples, respectively; (ii) simulation and experimental quantification of the biophysical responses of the trehalose-laden hADSCs to freezing and drying including cell dehydration and intracellular ice formation important for cell survival; and (iii) analysis of the morphology, survival, long-term proliferation, and stem cell properties and functions of the primary hADSCs after freeze-drying and banking at ambient temperature. The stem cell properties and functions will be assessed by the expression of stem cell gene and protein markers and their capability of adipogenic, osteogenic, and chondrogenic differentiation. A high survival and intact function of the primary hADSCs are anticipated after freeze-drying and long-term storage at ambient temperature under optimal conditions.This award by the Biotechnology and Biochemical Engineering Program of the CBET Division is cosponsored by the Biomaterials Program of the Division of Materials Research.