Fast Freezing Processes in Tissues

组织中的快速冷冻过程

基本信息

批准号：
10798699
负责人：
Ram Devireddy
金额：
$ 8.53万
依托单位：
LOUISIANA STATE UNIV A&M COL BATON ROUGE
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-06-01 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10798699
关键词：
Artificial tissue Award Calorimetry Cell Separation Cells Collagen Cryopreservation Cryoprotective Agents Data Dermal Development Diamond Differential Scanning Calorimetry Discipline Disparate Education Engineering Equipment Excision Fibroblasts Formulation Freezing Funding Gel Goals Heating Heterogeneity Instruction Knowledge Liver Measurement Measures Methodology Methods Microfabrication Microscopy Modeling National Institute of General Medical Sciences Optics Process Protocols documentation Research Resources Scanning System Techniques Technology Testing Thermodynamics Tissue Engineering Tissues United States National Institutes of Health Water biological systems biophysical properties cold temperature design extracellular infrastructure development instrument neonatal human predicting response rational design sensor undergraduate student

项目摘要

PROJECT SUMMARY (ORIGINAL) The goal of the research is to advance the formulation of cryopreservation protocols for biological systems using fundamental biophysical parameters. At present, crucial gaps exist in our knowledge of the biophysical parameters governing the states of intra- and extra-cellular water during a fast freezing process. This proposal aims to redress this crucial gap by introducing two new and effective techniques: (a) a measurement technique based on microscale thermoelectric sensors, engineered using microfabrication techniques suitable for use with artificial tissues and (b) a measurement technique based on a combination of calorimetry and low temperature microscopy suitable for use with native tissues. Specifically, the project will: (1) design fabricate and test microscale thermoelectric sensors to measure fast freezing processes in isolated cells (Neonatal Human Dermal fibroblasts, NHDFs) and artificial tissues (NHDFs embedded in a collagen gel sheet) with and without Cryoprotective Agents (CPAs) and (2) develop a combination of calorimetric and low temperature microscopy (directional solidification) methods to assess fast freezing processes in NHDFs and native (mammalian liver) tissue sections with and without CPAs. CPA addition and removal in both tissue (artificial and native) systems will be modeled using irreversible thermodynamic models. These integrated methods from disparate disciplines will lead to rational design and development of freezing processes for cryopreservation of donated tissues, an extremely scarce resource, as well as artificially engineered tissues. The education and infrastructure development part of this NIH AREA 15 proposal includes both instructional and research components for LSU undergraduate students. PROJECT SUMMARY (NIGMS Supplemental Award) The NIGMS supplemental (equipment) award requests funds to purchase a state of the art differential scanning calorimeter (DSC 8500) to enhance the quality of the data obtained in Aim 2 of the project. The new instrument will allow us to limit measurement errors and to assess the true contribution of cell heterogeneity. In addition, the new instrument will controllably freeze cells to a much higher rates (~750 ˚C/min) thus allowing us to fully accomplish the goals of the original proposal, i.e., to assess fast freezing processes in tissues.

项目摘要（原始）该研究的目的是推进生物系统冷冻保存方案的公式使用基本的生物物理参数。目前，我们对生物物理的了解存在关键差距在快速冻结过程中管理和细胞外水状态的参数。这个建议旨在通过引入两种新的有效技术来纠正这一关键差距：（a）测量基于微观热电传感器的技术，采用微加工技术设计适用于人造时间和（b）基于量热法的组合的测量技术和低温显微镜，适合与天然组织一起使用。具体而言，项目将：（1）设计制造和测试微观热电传感器以测量孤立细胞中的快速冰冻过程（新生儿人皮肤成纤维细胞，NHDFS）和人造组织（NHDF嵌入胶原蛋白凝胶中带有和没有冷冻保护剂（CPA）的表格），（2）形成量热和低的组合温度显微镜（定向固化）方法，以评估NHDF中的快速冻结过程有和没有CPA的天然（哺乳动物肝）组织切片。两组中的CPA添加和去除（人工和天然）系统将使用不可逆的热力学模型进行建模。这些整合来自不同学科的方法将导致冻结过程的合理设计和开发对捐赠的组织的冷冻保存，一种极为稀缺的资源以及人工设计的组织。 NIH地区的教育和基础设施发展部分15提案包括两种教学以及LSU本科生的研究组件。项目摘要（NIGMS补充奖） NIGMS补充（设备）奖要求资金购买最差异的状态扫描量热计（DSC 8500），以提高项目目标2中获得的数据质量。这新工具将使我们能够限制测量错误并评估细胞的真实贡献异质性。此外，新仪器将控制将细胞冻结至更高的速率（〜750 °C/min）因此使我们能够完全实现原始建议的目标，即评估快速冻结组织中的过程。