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ABSTRACT ARCHIVE |
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CryoLetters is a bimonthly, international journal for low temperature science and technology |
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CryoLetters 39 (1), 1-6 (2018) MODELING AND SIMULATION OF A MICROCHANNEL COOLING SYSTEM FOR VITRIFICATION OF CELLS AND TISSUES Wang Yang,1 Zhou Xiaoming,1,2,* Jiang Chaojie,1 Yu Yating1 1School of Mechanical, Electronic and Industrial Engineering; Abstract BACKGROUND: The microchannel heat exchange system has several advantages and can be used to enhance heat transfer for vitrification. OBJECTIVE: To evaluate the microchannel cooling method and to analyze the effects of key parameters such as channel structure, flow rate and sample size. MATERIALS AND METHODS: A computational flow dynamics model is applied to study the two-phase flow in microchannels and its related heat transfer process. The fluid-solid coupling problem is solved with a whole field solution method (i.e., flow profile in channels and temperature distribution in the system being simulated simultaneously). RESULTS AND CONCLUSION: Simulation indicates that a cooling rate >104 ºC/min is easily achievable using the microchannel method with the high flow rate for a board range of sample sizes. Channel size and material used have significant impact on cooling performance. Computational flow dynamics is useful for optimizing the design and operation of the microchannel system. Keywords: Computational flow dynamics, cooling microchannel, vitrification
CryoLetters 39 (1), 7-13 (2018) A LOW-COST EASY-TO-FABRICATE SANDWICH-STRUCTURED MICRODEVICE FOR CONTROLLABLE REMOVAL OF EXTRACELLULAR CRYOPROTECTIVE AGENTS WITH HIGH EFFICIENCY Kashan Memon1,#, Yue Cheng1,#, Fazil Panhwar1, Zhongrong Chen1, 1Department of Electronic Science and Technology, University of Science and Technology of China, Hefei; Abstract BACKGROUND: Osmotic shock upon the addition and removal of cryoprotectant agent (CPA) is a major source of cell damage during cryopreservation. OBJECTIVE: Microfluidic device offers a new platform for CPA loading and unloading. The micro scale dimension makes possible to perform a detailed analysis and controllable removal of CPA with many advantages. MATERIALS AND METHODS: A microfluidic device was developed for extracting dimethyl sulfoxide (DMSO) from the sample streamline. The device has two parallel channels separated by a polytetrafluoroethylene (PTFE) membrane, and serves as the stable environment for CPA removal. A diffusion-based simulation model was used to characterize the CPA extraction. To support the experimental design and device optimization we developed analogous scheme to simulate by COMSOL Multiphysics. RESULTS AND CONCUSION: The device can extract cryoprotectant in a mesoscale volume from cells and simplify the post-thaw sample handling. It has sufficient control on loading/unloading of CPAs by controlling the Ӿow rate of cell stream/wash stream solutions via syringe pumps. Compared to other customary devices, this device is easy to fabricate and assemble, with features of high precision, reusability and low cost. Keywords: DMSO, cryoprotectant loading, microfluidic device, PTFE membrane
CryoLetters 39 (1), 14-38 (2018) ALGINATE ENCAPSULATION TO ENHANCE BIOPRESERVATION SCOPE AND SUCCESS: A MULTIDISCIPLINARY REVIEW OF CURRENT IDEAS AND APPLICATIONS IN CRYOPRESERVATION AND NON-FREEZING STORAGE Benson EE1, Harding K1, Ryan M2, Petrenko A3A, Petrenko Y3,4A
1Damar Research Scientists, Damar, Drum Road, Cuparmuir, Fife, KY15 5RJ, Scotland, UK Abstract BACKGROUND: The development of encapsulation technologies has played an important role in improving cryopreservation outcomes for many cell and tissue types over the past 20 years. Alginate encapsulation cryopreservation (AECryo) has been incorporated into a range of applications in biotechnology, species conservation and clinical therapies, using cells from many different phyla, including higher plants, animal and human cells. This review describes the background to the origins of AECryo, the development of AECryo in higher plant tissues, broadening to current applications in algal conservation, the roles for AECryo in preserving phytodiversity, fungal species and in animal and human cells. OBJECTIVE: The main aims are to provide information resources on AECryo in different areas of biology and to stimulate new ideas for wider applications and future improvement. The translation of this useful biopreservation strategy into new opportunities for cell cryopreservation and storage at non-freezing temperatures are also discussed. Keywords: alginate, encapsulation, cryopreservation, plant tissues, algae, fungal species, mammalian and human tissues and cells, hypothermic storage, phytodiversity, biotechnology, regenerative medicine
CryoLetters 39 (1), 39-44 (2018) PARTIAL RECOVERY OF MITOCHONDRIAL FUNCTION OF VITRIFIED PORCINE MII STAGE OOCYTES DURING POST-THAW INCUBATION Jianjun Dai1,2, Junhua Yang1,2, Shushan Zhang1,2, Yingfang Niu1,2, 1Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences; Abstract BACKGROUND: The survival of porcine oocytes is still very low after cryopreservation. OBJECTIVE: To investigate whether and when the mitochondrial function of vitrified porcine oocytes could be recovered post-thaw MATERIALS AND METHODS: Mitochondrial potential ΔΨm ROS level, ATP content, apoptotic rate, caspase activity, and parthenogenetics developmental ability of thawed porcine oocytes were measured after culture in vitro for 0, 1, 2 or 4 h. RESULTS: Mitochondrial ΔΨm after 2 h and 4 h post-thaw culture were 1.19 and 1.26, significantly lower than that of fresh oocytes but much higher than the groups cultured for 0 h and 1 h (P<0.05). Cryopreservation increased the ROS level in oocytes considerably, which decreased only after 2 to 4 h incubation following thaw. ATP content increased gradually over time, and recovered to the level comparable to that of fresh oocytes after 4 h. Pan caspase levels increased after cryopreservation and reached the highest level at 1 h incubation. Thereafter it decreased to a low value, but still higher than fresh oocytes. Oocytes showing an early apoptotic event decreased upon 2 to 4 h incubation. The parthenogenetic cleavage and blastocyst rates were the highest (19.8% and 5.6%) after 2 h incubation. CONCLUSION: T he recovery of mitochondrial function could complete after 2 to 4 h post-thaw incubation. Post-thaw incubation for 2 to 4 h reduced apoptotic events and improved parthenogenetic developmental ability of vitrified porcine MII stage oocytes. Keywords: porcine ooctyes; vitrification, mitochondrial function, apoptosis
CryoLetters 39 (1), 45-52 (2018) DOG SPERM CRYOPRESERVATION IN GLUCOSE-FRUCTOSE OR SUCROSE SUPPLEMENTED GLYCEROL-FREE TRIS: EFFECT OF POST-THAW INCUBATION TIME ON GENE EXPRESSION RELATED TO APOPTOSIS AND MOTILITY Md. Ataur Rahman1,2#, Sang-Hyoun Park1# and Il-Jeoung Yu1*, 1Laboratory of Theriogenology & Reproductive Biotechnology, College of Veterinary Medicine and Biosafety Research Institute, Chonbuk National University, Republic of Korea. Abstract OBJECTIVE: The study evaluated the effects of glucose-fructose or sucrose supplementation in glycerol-free Tris (GFT) solution on motility, viability, the level of reactive oxygen species (ROS), as well as the level of apoptosis (BAX and BCL2) and motility (SMCP)-related gene expression of dog spermatozoa. MATERIALS AND METHODS: Spermatozoa (5×107 sperm/ml) were cryopreserved in GFT containing 86 mM glucose and 86 mM fructose (GF-GFT) or 100 mM sucrose (S-GFT). Progressive motility, viability, ROS (H2O2) level and mRNA gene expression of spermatozoa were evaluated 0 h, 3 h or 6 h post-thaw at 24°C. RESULTS: The motility of spermatozoa cryopreserved in GF-GFT was increased throughout the post-thaw incubation time. The motility of spermatozoa cryopreserved in S-GFT was increased at 3 h of post-thaw incubation. The sperm ROS level in the GF-GFT group was inconsistent during the post-thaw incubation time; however, the ROS level in the S-GFT group was gradually increased with progression of the post-thaw incubation period. The post-thaw incubation had no substantial effect on the mRNA expression of the BAX, BCL2, and SMCP genes of spermatozoa in both the GF-GFT and S-GFT groups. CONCLUSION: The supplementation of glucose and fructose improves progressive sperm motility during 6 h of post-thaw incubation while maintaining similar sperm viability. The addition of GF to GFT for cryopreservation and post-thaw incubation would yield more functional spermatozoa for future assisted reproduction practices. Keywords: dog sperm, cryopreservation, gene expression, glucose, sucrose, fructose, tris (hydroxymethyl) aminomethane
CryoLetters 39 (1), 53-59 (2018) EFFECTIVE CONDITION FOR WHOLE TESTIS CRYOPRESERVATION OF ENDANGERED MIHO SPINE LOACH (Cobitis choii) THROUGH THE OPTIMIZATION OF MUD LOACH (Misgurnus mizolepis) WHOLE TESTIS CRYOPRESERVATION CONDITION Jungju Kim1, Yoon Kwon Nam1,2, In-Chul Bang3 1Department of Fisheries Biology and Abstract BACKGROUND: Miho spine loach (Cobitis choii) is an endangered Korean endemic fish. Whole testis cryopreservation is a good way for species preservation, but needs to the sacrifice of a large number of fish to optimize the freezing condition. Considering this limitation, a surrogate fish species was used for the protocol development. OBJECTIVE: This study was to establish the effective condition for Miho spine loach whole testis cryopreservation by optimizing the conditions for whole testis cryopreservation in an allied species, mud loach (Misgurnus mizolepis). MATERIALS AND METHODS: The condition for whole testis cryopreservation was optimized in mud loach first, and then the optimal condition was applied to Miho spine loach testes. RESULTS: The optimal condition for mud loach testis cryopreservation consists of the freezing medium containing 1.3 M dimethyl sulfoxide, 6% fetal bovine serum and 0.3 M trehalose, –1˚/min cooling rate and 26˚C thawing temperature, which also permits effective cryopreservation of Miho spine loach testes. CONCLUSION: An effective cryopreservation condition for whole testis of the endangered Miho spine loach has been established by using mud loach as a surrogate fish. Keywords: cryopreservation, whole testis, endangered fish species, Miho spine loach, mud loach
CryoLetters 39 (1),60-66 (2018) RECOVERY OF OIL PALM (Elaeis guineensis Jacq.) SOMATIC EMBRYOS CRYOSTORED FOR 20 YEARS Thierry Beulé1, Pascal Ilbert1, Kifouli Adeoti2, 1CIRAD, Université Montpellier, UMR DIADE, F-34398 Montpellier, France Abstract BACKGROUND: A cryopreservation protocol has been established for oil palm somatic embryos (SEs), the efficiency of which must be evaluated, both in terms of regeneration and of long-term storage capacity, before its large-scale routine use. OBJECTIVE: To test the survival and recovery of 29 clones of oil palm somatic embryos cryostored for 20 years. MATERIALS AND METHODS: Clumps of SEs were pregrown for 7 days on medium containing 0.75 M sucrose, dehydrated in air-tight containers containing silica gel to moisture contents between 19-35% fresh weight, and then immersed directly in liquid nitrogen and stored in cryotanks for 20 years. RESULTS: Survival of SEs cryopreserved and rewarmed immediately displayed an average value of 19.1% for the 29 clones tested while survival of SEs rewarmed after 20 years of cryostorage was significantly higher, with an average of 33.2% for the 28 surviving clones. Out of these 28 surviving clones, three were lost due to contamination or regrowth decline, six produced only shoots and the rest proliferated. CONCLUSION: It is possible to cryostore oil palm SEs for extended periods and to regenerate proliferating cultures and plantlets from the cryopreserved material. The cryopreservation protocol established can thus be efficiently used to store oil palm germplasm and to manage large-scale production in industrial laboratories. Keywords: cryopreservation, Elaeis guineensis, somatic embryos, tissue-culture, germplasm, preservation
CryoLetters 39 (1), 67-71 (2018) Variable inter-assay estimation of sperm DNA fragmentation in STALLIONS CLASSIFIED AS GOOD AND BAD SEMEN FREEZERs H. N. Ferreira1, J. C. Ferreira-Silva1, J. M. Rocha1, M. C. Fárras3, 1Laboratório de Biotecnologias Reprodutivas, Departamento de Medicina Veterinária (UFRPE), Recife-PE, Brasil. Abstract BACKGROUND: Semen cryopreservation causes DNA damage, thus requiring continuous monitoring. OBJECTIVE: To compare two assays for sperm DNA fragmentation (SDF) from stallions with contrasting semen freezability. MATERIALS AND METHODS: Thirteen stallions were classified as good semen freezers (GSF) or bad semen freezers (BSF). Ejaculates were cryopreserved with three diluents. Semen was subject to SDF evaluation using the sperm chromatin structure assay (SCSA) and Halomax® after thawing (0 h) and after a 4 h thermoresistance test. RESULTS: On semen of BSF, analysis by SCSA was similar between evaluations, but Halomax® showed increased SDF at 4 h. The GSF group was similar between time points in both assays. Diluents did not affect SDF, irrespective of the assay. Halomax® showed differences for BSF between time points, differently from SCSA. Linear regression did not show any correlation between assays. CONCLUSION: The use of Halomax® should be encouraged for sperm DNA fragmentation analysis in horse frozen-thawed semen, particularly under field conditions. Keywords: reproduction, cryobiology, equine, spermatozoa
CryoLetters 39 (1), 72-78 (2018) APPLICATION OF PECTIN FROM Rauvolfia serpentina (L.) Benth TO THE CRYOPRESERVATION OF HUMAN LEUCOCYTE CELL SUSPENSIONS О.О. Zaitseva*, Т.V. Polezhaeva, А.N. Khudyakov*, Physiology Institute at the Komi Scientific Center of the Russian Academy of Sciences, Komi Republic, Syktyvkar, Russian Federation Abstract BACKGROUND: Due to their valuable medicinal properties and high physiological activity, plant polysaccharides are currently being extensively studied. OBJECTIVE: The present study aims to investigate rauwolfian (pectin for Rauvolfia serpentina) supplementation on human leukocytes cryopreservation. We determined the сharacteristics of leukocytes undergoing freezing with pectin at different temperatures. METHODS: Donor leukocytes were frozen under the protection of comprehensive cryoprotectant solution and stored in electrical freezers (-20°C, -40°C, -80°C). RESULT: A regular decrease of all values starting from a higher temperature (-20°С) through to the lower temperature (-80°С) was identified. The study showed that pectin rauwolfian stimulated both the oxygen-independent and the oxygen-dependent killer response. We also found that the oxygen-dependent neutrophil killer effect was reduced as the storage temperature was lowered. It was determined that the LPO levels in the cells with added pectin-containing solutions remained the same before freezing, while their antioxidant activity positively increased, which is beneficial for neutrophils for their further freezing to -20°C, -40°C and -80°C. CONCLUSIONS: The results of the study make it possible to assume that rauwolfian, a pectin extracted from Rauvolfia serpentina, has an exocellular protectant effect as part of cryopreservative solution on human white blood cells stored at different low temperatures. The versatility of the substance is probably due to the degree of the macromolecule branching, in particular, the structure of carbohydrate side chains, which contain a large number of hydroxyl groups. Keywords: leukocytes, neutrophils, pectin, Rauvolfia serpentina, cryoprotective, lipid peroxidation, antioxidant activity |
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For Abstracts published from meetings, such as SLTB meetings, go to the
relevant Volume Year of the journal (above). For Full text Free Access Content (from 2000 onwards) go to CryoLetters at Ingenta and look for the blue symbol. |
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