SusCHEM: Fundamental Studies on Lyopreservation of Adult Stem Cells

在常温下将活细胞在假死状态下进行冷冻保存，可以实现细胞的低成本维护和方便分布。细胞的可用性对于细胞疗法的广泛应用和最终成功至关重要，包括组织工程、再生医学、细胞移植、输血和干细胞治疗。本项目的目的是进行一项系统的研究，以了解海藻糖（一种无毒糖）在冷冻和干燥含海藻糖的人类脂肪源性干细胞（hADSCs）以及在室温下储存干燥细胞过程中的保护作用。由于海藻糖已被用于许多低等生物在自然界的极端寒冷和干旱中生存，因此假设含有海藻糖的干细胞也会有类似的行为。该项目将对改善医疗保健产生重大影响，促进细胞冷冻保存技术的发展，使细胞为基础的医学治疗取得成功。使用一种无毒的糖（海藻糖）来代替有毒的化学物质（如二甲基亚砜或二甲基亚砜）用于细胞库，这与NSF SusCHEM计划非常一致，该计划旨在用地球上丰富的、廉价的、良性的材料取代有毒的化学物质。为了了解在环境温度下在假死状态下干燥活细胞以供储存的基础科学，提出了三个具体的研究任务。这些包括(i)研究冷冻干燥参数对海藻糖溶液干燥动力学的影响，这对原始hascs的冷冻保存很重要，对干燥产品的微观形态也很重要，分别使用冷冻干燥显微镜和台式冷冻干燥机对小样本和大样本进行研究；（ii）模拟和实验量化海藻糖负载的hscs对冷冻和干燥的生物物理反应，包括细胞脱水和细胞内冰的形成，这对细胞存活很重要；（iii）分析原代hscs在冷冻干燥和常温保存后的形态、存活、长期增殖、干细胞特性和功能。干细胞的特性和功能将通过干细胞基因和蛋白质标记物的表达及其成脂、成骨和成软骨分化的能力来评估。在最佳条件下冷冻干燥和长期保存后，原代hscs的存活率高，功能完整。该奖项由CBET部生物技术与生物化学工程项目与材料研究部生物材料项目共同主办。

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.