The over-all goal of this application is to establish a universal and easy-to-use germplasm cryopreservation approach by developing a novel ultra-fast cooling device system. This device system achieves vitrification of germplasm suspensions without any cryoprotective agent (CPA) or with low concentration CPA (<1M). We will do this by combining cutting-edge engineering techniques including: (1) cryogenic thin film evaporation (TFE), (2) thermal fins, and (3) microfabrication techniques. Germplasm cryopreservation is essential to many areas of medicine such as reproductive medicine, oncology, and gene therapy. However, current cryopreservation methods and devices are very different for different types of germplasms or even within cell types and they are sometimes very difficult to use. Due to the complications and inefficiencies involved in these methods, many cells types cannot be successfully cryopreserved at all and many others respond very poorly to current methods (i.e., more than 50% of the cells are lost during the process). Therefore, it is important to establish a universal, efficient cell cryopreservation method and develop corresponding devices that require relatively simple operations. Direct vitrification (solidification without crystal formation) of cell suspensions without permeating CPAs (e.g. glycerol and DMSO), or with relatively low concentrations (<1M) of CPAs, is suitable for cryopreservation of essentially all cell types. This is the case because (1) vitrification prevents cell damages caused by ice formation;(2) a low concentration of CPA significantly lowers CPA toxicity and osmotic damages during CPA addition and removal procedures. However, vitrification with low concentration CPAs requires ultra-fast cooling rates (106-7K/min). Since none of the current cryopreservation methods and devices can achieve these ultra-fast cooling/warming rates, successful completion of this work will significantly enhance the underlying infrastructure for many areas of biomedical research and save a significant amount of resources by providing a universal, effective cell cryopreservation system. This work will be done by completing the following specific aims: (1) theoretical and experimental investigations on applications of the three cutting-edge techniques in cryopreservation, (2) determination of the optimal design of the proposed device system based on the above investigations, and (3) empirical testing the device system by cell survival rates.
(provided by applicant): Germplasm cryopreservation is essential to many areas of medicine such as reproductive medicine, oncology, and gene therapy. However, current cryopreservation methods and devices are very different for different types of germplasms or even within cell types and they are sometimes very difficult to use. The over-all goal of this application is to establish a universal and easy-to-use germplasm cryopreservation approach by developing a novel ultra-fast cooling device system.
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