SusCHEM: Fundamental Studies on Lyopreservation of Adult Stem Cells

1605425何、晓明将活体细胞在常温下以悬浮状态保存存库，可以实现低成本的维护和方便的细胞分布。细胞的可获得性对基于细胞的治疗的广泛应用和最终成功至关重要，这些治疗涉及组织工程、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(一种无毒的糖)在富含海藻糖的人脂肪干细胞(HADSCs)冷冻和干燥过程中的保护作用，并在常温下保存干燥的细胞。由于海藻糖已被许多低等生物用来在自然界的极端寒冷和干旱中生存，因此假设携带海藻糖的干细胞也会有类似的行为。该项目将通过促进细胞冷冻保存技术的发展，为基于细胞的医疗治疗的成功提供支持，从而对改善医疗保健产生重大影响。使用无毒的糖(海藻糖)取代有毒化学物质(例如二甲基亚砜或DMSO)用于细胞库，与NSF SusCHEM用地球资源丰富、廉价和无害的材料取代有毒化学物质的倡议非常一致。为了了解银行在常温下处于悬浮状态下干燥活细胞的基础科学，提出了三项具体的研究任务。这包括(I)分别使用冷冻干燥显微镜和台式冷冻干燥机研究冷冻干燥参数对冷冻保存原代hADSCs重要的海藻糖溶液干燥动力学和干燥产品微观形态的影响；(Ii)模拟和实验量化负载海藻糖的hADSCs在冷冻和干燥过程中的生物物理响应，包括细胞脱水和对细胞生存至关重要的细胞内冰的形成；(Iii)分析冷冻干燥和常温储存后原代hADSCs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以及它们的成脂、成骨和成软骨分化能力来评估。在最佳条件下，原代hADSCs经过冷冻干燥和长期储存后，有望获得高存活率和完整的功能。该奖项由CBET分部生物技术和生化工程计划主办，由材料研究部生物材料计划共同主办。

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.