Ice Nucelation in Biological Tissues - Implications to Cryopreservation

生物组织中的冰成核 - 对冷冻保存的影响

• 批准号: 7142815
• 负责人: Ram Devireddy
• 金额: $ 7.35万
• 依托单位: LOUISIANA STATE UNIV A&M COL BATON ROUGE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7142815
• 关键词: cryopreservation; extracellular; intracellular; liver; liver cells; sectioning; tissues; water

DESCRIPTION (provided by applicant): Summary: The use of liver tissue cells either as isolated hepatocyte suspensions or whole liver tissue slices represents a promising approach to temporary replacement of liver function using bioartificial liver devices. However, the bioartificial liver devices need a readily available source of hepatocytes and whole liver tissue slices, as do the xenobiotic studies of clinical drugs. One technique capable of achieving long term storage of liver cells and tissue slices is the use of low temperatures, i.e. cryopreservation. Although extensive research has been performed to determine the effect of freezing protocol and cryopreservation agents on the viability of hepatocytes and whole liver slices, the development of efficient cryopreservation protocols is still hindered by a lack of fundamental understanding of the physicochemical properties governing the response of whole liver tissue cells to freezing injury. Hypotheses: Knowledge of intracellular ice formation in liver tissue sections will enhance our ability to rationally design and optimize freeze/storage protocols. To test the hypothesis, we will measure the kinetics of ice nucleation in liver tissue sections using a combination of 2 recently developed techniques, one based on low temperature microscopy and another on calorimetry. The proposed technique, if successful, will give the biologist or bioengineer a complete understanding of the freezing processes in tissue sections and will ultimately, lead to better long-term storage protocols for native tissues. Specific Aims: In order to test our hypotheses, the following aims will be accomplished. SA 1: Validation of the proposed technique. Comparison of the ice nucleation data in single isolated cells obtained using the new technique and with a well established cryomicroscopy procedure. SA2: Extension of the technique to measure ice nucleation kinetics in whole tissues. SA3: Modeling and prediction of ice nucleation kinetics in whole tissue sections.

描述（由申请人提供）：总结：使用肝组织细胞作为分离的肝细胞悬液或整个肝组织切片代表了使用生物人工肝装置暂时替代肝功能的有前景的方法。然而，生物人工肝装置需要一个容易获得的肝细胞和全肝组织切片的来源，因为这样的临床药物的异生物质研究。能够实现肝细胞和组织切片的长期储存的一种技术是使用低温，即冷冻保存。虽然已经进行了广泛的研究，以确定冷冻方案和冷冻保存剂对肝细胞和全肝切片的活力的影响，但由于缺乏对全肝组织细胞对冷冻损伤的反应的物理化学性质的基本理解，有效的冷冻保存方案的开发仍然受到阻碍。假设：肝组织切片中细胞内冰形成的知识将提高我们合理设计和优化冷冻/储存方案的能力。为了验证这一假设，我们将使用2种最近开发的技术（一种基于低温显微镜，另一种基于量热法）来测量肝组织切片中冰成核的动力学。所提出的技术，如果成功的话，将使生物学家或生物工程师对组织切片的冷冻过程有一个完整的了解，并最终导致更好的天然组织的长期储存协议。具体目标：为了验证我们的假设，将实现以下目标。SA 1：所提出技术的验证。比较使用新技术获得的单个孤立细胞中的冰核数据和已建立的低温显微镜程序。SA 2：扩展技术以测量整个组织中的冰成核动力学。SA 3：整个组织切片中冰成核动力学的建模和预测。