Immortality: desiccation of human (stem) cells for long-term storage and cell therapy-based applications

尽管有证据表明，在干燥状态下制备哺乳动物细胞可能是一种可行的长期储存策略，但没有研究证明一个成功的方案。考虑到临床转化终点，该项目旨在确定可用于开发耐干燥细胞系的材料和/或技术，以期随后临床应用于人类干细胞。本项目可分为以下几个活动：1.项目内容：评估水凝胶、凝胶基材料和/或外源添加剂/补充剂作为细胞长期干燥保存“保护剂”的可行性。样品将包括生物来源的凝胶，如胶原蛋白/明胶、琼脂糖和植物性凝胶；合成材料如甲基丙烯酸缩水甘油酯（GMA）、聚异丙基丙烯酰胺（PNIPAAm）；补充如晚期胚胎发生丰富（LEA）蛋白，热休克蛋白（来自极端微生物）。材料将在培养、干燥和再水化过程中对细胞的支持进行充分的表征和评估。为了评估干燥过程中涉及的“处理”参数：由于晶体生长、成核位置等基本机制的差异，控制水分的去除——无论是快速还是缓慢——都会影响细胞在干燥过程中的存活。类似的过程/机制发生在这些细胞的再水化过程中，这将影响干细胞的生存能力和潜在的分化能力。该项目的这一部分将旨在确定细胞脱水和再水化的最佳速率/方法。该项目的这一部分也可能利用潜在的计算分析来模拟样品中的水分损失。

Although evidence exists that suggests the preparation of mammalian cells in a desiccatedstate may be a feasible strategy for their long-term storage, no study has documented asuccessful protocol. Considering a clinical translational endpoint, this project aims to identifymaterials and/or techniques that can be applied to develop a desiccation-tolerant cell linewith the view of subsequent clinical application to human stem cells.The project can be divided into the following activities:1. Assessment of the feasibility of hydrogels, gel-based materials and/or exogenousadditives/supplements as "protectants" for cells undergoing a desiccation protocol for longtermstorage. Samples will include biologically-derived gels such as collagen/gelatin, agaroseand plant-based gels; synthetic materials such as glycidyl methacrylate (GMA), poly(Nisopropylacrylamide)(PNIPAAm); supplements such as Late Embryogenesis Abundant (LEA)proteins, heat-shock proteins (from extremophiles). Materials will be fully characterized andassessed for their support of cells during culture, desiccation and rehydration.2. To assess the "processing" parameters involved in the drying process: controlled removalof water - either in a rapid or slow manner - will affect cell survival during desiccation due tothe differences in the fundamental mechanisms i.e. crystal growth, nucleation sites. A similarprocess/mechanism occurs during rehydration of these cells, which would impact theresulting viability and potential differentiative ability of the (stem) cells. This part of theproject will aim to identify the optimal rate/methodology of de- and re-hydrating the cells.Potential computational analyses may also be exploited in this part of the project to modelthe water loss from the samples.