Cryopreservation of red blood cells(RBCs)provides great potential benefits for providing transfusion timely in emergencies.High concentrations of glycerol(20%or 40%)are used for RBC cryopreservation in current clinica...Cryopreservation of red blood cells(RBCs)provides great potential benefits for providing transfusion timely in emergencies.High concentrations of glycerol(20%or 40%)are used for RBC cryopreservation in current clinical practice,which results in cytotoxicity and osmotic injuries that must be carefully controlled.However,existing studies on the low-glycerol cryopreservation of RBCs still suffer from the bottleneck of low hematocrit levels,which require relatively large storage space and an extra concentration process before transfusion,making it inconvenient(time-consuming,and also may cause injury and sample lose)for clinical applications.To this end,we develop a novel method for the glycerol-free cryopreservation of human RBCs with a high final hematocrit by using trehalose as the sole cryoprotectant to dehydrate RBCs and using core–shell alginate hydrogel microfibers to enhance heat transfer during cryopreservation.Different from previous studies,we achieve the cryopreservation of human RBCs at high hematocrit(>40%)with high recovery(up to 95%).Additionally,the washed RBCs post-cryopreserved are proved to maintain their morphology,mechanics,and functional properties.This may provide a nontoxic,high-efficiency,and glycerol-free approach for RBC cryopreservation,along with potential clinical transfusion benefits.展开更多
Ligament cryopreservation enables a prolonged shelf life of allogeneic ligament grafts,which is fundamentally important to ligament reconstruction.However,conventional cryopreservation techniques fail to eliminate the...Ligament cryopreservation enables a prolonged shelf life of allogeneic ligament grafts,which is fundamentally important to ligament reconstruction.However,conventional cryopreservation techniques fail to eliminate the damage caused by ice crystal growth and the toxicity of cryopreservation agents(CPAs).Here,we report a novel CPA vitrification formulation primarily composed of betaine for ligament cryopreservation.Comprehensive optimization was conducted on the methods for vitrification and rewarming,as well as the loading and unloading conditions,based on the critical cooling rate(CCR),critical warming rate(CWR),and permeation properties of the CPA.Using biomechanical and histological level tests,we demonstrate the superior performance of our method in ligament cryopreservation.After 30 days of vitrification cryopreservation,parameters such as the Young's modulus,tensile stress,denaturation temperature,and glycosaminoglycans content of the ligament remained essentially unchanged.This work pioneers the application of ice-free cryopreservation for ligament and holds great potential for improving the long-term storage of ligament,providing valuable insights for future cryopreservation technique development.展开更多
Teratozoospermia is an infertility issue that affects a significant number of couples of reproductive age. One of the potential causes contributing to the global decline in seminal quality includes factors such as die...Teratozoospermia is an infertility issue that affects a significant number of couples of reproductive age. One of the potential causes contributing to the global decline in seminal quality includes factors such as diet, alcohol and tobacco consumption, high levels of stress, and environmental influences. This underscores the need to preserve the fertility of these patients through cryopreservation techniques. In this review, we explore the latest methods for freezing seminal samples, highlighting their advancements and advantages in addressing the challenge of perpetuating animal species, particularly in the context of human infertility.展开更多
Preserving microbial diversity has become a strategic undertaking. Thus, ex situ microalgal culture conservation results in strategic and functional resource in both biodiversity protection and application domains. Cr...Preserving microbial diversity has become a strategic undertaking. Thus, ex situ microalgal culture conservation results in strategic and functional resource in both biodiversity protection and application domains. Cryopreservation of microalgae has been practiced since the 1960s and is now considered the optimal preservation strategy. Furthermore, the overall monitoring during growth of cultures after freezing/thawing protocols was hardly investigated and there is poor evaluation related to preserve especially the photosystem apparatus. The present study focuses on Stichococcus bacillaris as case study for short-term cryopreservation at −80 °C storage. Various freezing pretreatments using cryoprotective agents, and two thawing methods were compared introducing a novel variable to evaluate viability recovery and assessing growth kinetics of cultures immediately after thawing and after a series batch cultivation. Photosynthetic rate and pigments assessment were proposed to evaluate hidden metabolic cell damage. Results underline cryoprotective agents can increase the kinetic recovery of preserved cells in terms of reduction of lag phase during batch cultivation tests: the use of dimethyl sulfoxide and glycerol granted a growth comparable to unpreserved cells when sudden thawing occurs after 24 hours of storage, but recovery after preservation is less sensitive to cryoprotective agents when gradual thawing and 1 month of storage is considered. However, cells are always able to restore their physiological pathways even without agents, so their kinetic effect has been proved and quantified. Interestingly, both the photosynthetic efficiency and the ratio between total chlorophyll and carotenoids are comparable (0.75 F<sub>v</sub>/F<sub>m</sub>, 2.2 ± 0.25 g/g) to unpreserved cells and they are unsensitive to chosen agents, but the ratio between chlorophyll a and chlorophyll b was clearly altered (up to 10 times), suggesting that photoactive pigments relative proportions can result in similar growth kinetic performances. Long-term studies will be carried out to assess whether the differences found could cause chronic damage to photosystem efficiency of S. bacillaris cultures.展开更多
Poultry genetics resources,including commercial selected lines,indigenous breeds,and experimental lines,are now being irreversibly lost at an alarming rate due to multiple reasons,which further threats the future live...Poultry genetics resources,including commercial selected lines,indigenous breeds,and experimental lines,are now being irreversibly lost at an alarming rate due to multiple reasons,which further threats the future livelihood and academic purpose.Collections of germplasm may reduce the risk of catastrophic loss of genetic diversity by guaranteeing that a pool of genetic variability is available to ensure the reintroduction and replenishment of the genetic stocks.The setting up of biobanks for poultry is challenging because the high sensitiveness of spermatozoa to freezing–thawing process,inability to cryopreserve the egg or embryo,coupled with the females being heterogametic sex.The progress in cryobiology and biotechnologies have made possible the extension of the range of germplasm for poultry species available in cryobanks,including semen,primordial germ cells,somatic cells and gonads.In this review,we introduce the state-of-the-art technologies for avian genetic resource conservation and breed reconstruction,and discuss the potential challenges for future study and further extending of these technologies to ongoing and future conservation efforts.展开更多
For men with severe oligozoospermia, sperm cryopreservation can preserve surgically obtained sperm. How to cryopreserve single sperm in men is still a hot topic in assisted reproduction technology. Aim to analyze the ...For men with severe oligozoospermia, sperm cryopreservation can preserve surgically obtained sperm. How to cryopreserve single sperm in men is still a hot topic in assisted reproduction technology. Aim to analyze the laboratory and pregnancy outcomes of single sperm cryopreservation group, we retrospectively selected 38 cycles underwent single sperm cryopreservation and thawing as the study group and 618 cycles underwent conventional sperm cryopreservation and thawing as the control group, which were performed in the reproductive medicine center of the Sixth Affiliated Hospital, Sun Yatsen University, from April 2014 to October 2023. All the sperm came from microdissection testicular sperm extraction (micro-TESE), and performed intracytoplasmic sperm injection (ICSI) for fertilization. Zygotes were cultured to Day 3 embryo, which were freshly transferred to female uterus. Surplus embryos were cultured to blastosphere and cryopreserved. There was no statistical difference in female/male age, female BMI, infertility duration and female basal sex hormone (FSH, LH E2, AMH), No. of oocytes retrieved per cycle, No. of ICSI oocytes per cycle and No. of embryos transferred per cycle between the two groups (P > 0.05). No significant difference was found in two-pronuclear oocyte fertilization rate (59.23% VS 58.84%), Day 3 available embryo rate (61.81% VS 63.55%), Day 3 good-quality embryo rate (45.73% VS 50.27%), blastocyst formation rate (47.83% VS 49.46%), the implantation rate (47.37% VS 52.16%), clinical pregnancy rate (36.84% VS 47.18%), miscarriage rate (14.29% VS 12.68%) and live birth rate (85.71% VS 81.70%) between two groups (P > 0.05). In conclusion, single-sperm cryopreservation was the optimal method to preserve sperm after micro-TESE. It can increase the utilization of each sperm and lead to clinical pregnancy.展开更多
Cryopreservation is currently the only effective tool for long-term storage of semen in most species. However, it is well-recognized that, even in species that freeze well, some individuals resist cryopreservation. Wo...Cryopreservation is currently the only effective tool for long-term storage of semen in most species. However, it is well-recognized that, even in species that freeze well, some individuals resist cryopreservation. Work from this laboratory has demonstrated a relationship between maternal lipid content and the chemical constitution of the embryos they produce. The objective of the present study was to determine if a similar relationship might exist in paternal body chemistry and the animal’s semen sample and if such a difference could be determined with a simple weight test. Semen samples were obtained from cattle with known differences in body composition. The samples first underwent semen analysis and were then prepared as either cell-free (CF) or neat specimens (NS). Known volumes of each sample were weighed, and the remainder of the samples was analyzed for lipids, total proteins, and total carbohydrates using a series of spectrophotometric assays and blood chemistry techniques. As expected, weight differences were seen in the CF vs NS preparations of individual semen samples (p < 0.001). Differences were also found in triglycerides (p < 0.001), glucose (p < 0.001), total protein (p < 0.001), and fructose (p < 0.009) of individuals with differing body composition. Statistical analysis suggested a non-linear correlation between the observed weights and total protein (p < 0.047) as well as triglyceride levels (p < 0.003). Together, these data suggest it might be possible to develop an algorithm to allow adjustment in cryoprotectants based on a simple weight procedure, allowing modification of cryoprotectants on an individual basis and potentially improving outcomes for valuable animals currently classified as “poor freezers”.展开更多
[Objective] The aim of this study was to establish the in vitro culture system of chicken fibroblasts.[Method] Tissue explant method and enzymatic digestion method were used to separate and culture chicken skin fibrob...[Objective] The aim of this study was to establish the in vitro culture system of chicken fibroblasts.[Method] Tissue explant method and enzymatic digestion method were used to separate and culture chicken skin fibroblasts respectively.The rate of cell growth,cryopreservation and recovery were compared.[Result] The primary chicken fibroblasts prepared by enzymatic digestion grew faster and converged together to form monolayer on 5 d post preparation;the passage cells prepared by these 2 methods grew at similar speed and formed monolayer within 2-3 d;homogeneous fibroblasts could be obtained by trypsin digestion and repeated attachment for 3-4 passages;there were 75%-80% of cells survived after cryopreservation and recovery;the growth curves of embryonic fibroblasts and skin fibroblasts were all normal and the two kind of cells still retained the normal number of chromosomes even at the twelfth passage.[Conclusion] The feeder layer cells needed for establishing ES cell lines could be obtained by culturing chicken fibroblasts through both tissue explant method and enzymatic digestion method.This study provided a basis for the successful establishment of ES cell lines.展开更多
Embryo cryopreservation(CP) has became a very important part of the clinical use of in vitro fertilization. Oocyte CP offers more advantages compared with embryo freezing with regard to less ethical, legal and moral...Embryo cryopreservation(CP) has became a very important part of the clinical use of in vitro fertilization. Oocyte CP offers more advantages compared with embryo freezing with regard to less ethical, legal and moral problems. However, the efficiency of this procedure is still low, which prevents its clinical application in wide range. The aim of our paper is to review the basic principles, technical and safety aspects and current status of oocyte cryopreservation in human assisted reproduction.展开更多
[Objective] This study aimed to investigate the effects of cryopreservation on the quality and ultrastructure of Tibetan Mastiff sperm. [Method] The effects of cryopreservation on the quality of Tibetan Mastiff sperm ...[Objective] This study aimed to investigate the effects of cryopreservation on the quality and ultrastructure of Tibetan Mastiff sperm. [Method] The effects of cryopreservation on the quality of Tibetan Mastiff sperm were evaluated via motility, membrane integrity rate and acrosome intact rate. On that basis, the effects of cryopreservation on ultrastructure of sperm were observed under SEM and TEM. [Result] In Experiment 1, EG gave the best results not only in post-thaw motility rate (36.3%), but also in low membrane integrity rate (38.0%) and acrosome intact rate (42.0% ), but there was no significant difference between EG group and Glycerol group (P0.05). In Experiment 2, the 5 cm freezing height obtained the best freezing-thawing results, but there was no significant difference between 2 and 5 cm height (P 0.05), besides in acrosome intact rate. In Experiment 3, SDS and Vc added separately or together into extenders could improve freezing-thawing results, but there was not obvious difference between SDS group and Vc group (P0.05), besides the lower motility of Vc group (P0.05). Addition of SDS and Vc obtained the best results in post-thaw motility rate (44.1%), and also in membrane integrity rate (48.0%) and acrosome intact rate (48.2%). The ultrastructure of frozen-thawed sperm was also evaluated under SEM and TEM, results showed that cryopreservation caused various degrees of damage to Tibetan Mastiff sperm, more serious damages were observed in the acrosome such as swelling, vesiculation and even disappearance. [Conclusion] This study confirms that EG, horizontal height of 0.25 ml straw above LN 2 surface and additives SDS and Vc together can improve freezing effect. However, cryopreservation has certain damage to ultrastructure of sperm.展开更多
Aim:To establish a method for cynomolgus monkey sperm cryopreservation in a chemically defined extender. Methods:Semen samples were collected by electro-ejaculation from four sexually mature male cynomolgus monkeys. T...Aim:To establish a method for cynomolgus monkey sperm cryopreservation in a chemically defined extender. Methods:Semen samples were collected by electro-ejaculation from four sexually mature male cynomolgus monkeys. The spermatozoa were frozen in straws by liquid nitrogen vapor using egg-yolk-free Tes-Tris (mTTE) synthetic extender and glycerol as cryoprotectant.The effects of glycerol concentration (1%,3 %,5 %,10 % and 15 % [v/v]) and its equilibration time (10 min,30 min,60 min and 90 min) on post-thaw spermatozoa were examined by sperm motility and sperm head membrane integrity.Results:The post-thaw motility and head membrane integrity of spermatozoa were significantly higher (P<0.05) for 5 % glycerol (42.95±2.55 and 50.39±2.42,respectively) than those of the other groups (1%:19.19±3.22 and 24.84±3.64;3 %:34.23±3.43 and 41.37±3.42;10 %: 15.68±2.36 and 21.39±3.14;15 %:7.47±1.44 and 12.90±2.18).The parameters for 30 min equilibration (42.95±2.55 and 50.39±2.42) were better (P<0.05) than those of the other groups (10 min:31.33±3.06 and 38. 98±3.31;60 min:32.49±3.86 and 40.01±4.18;90 min:31.16±3.66 and 38.30±3.78).Five percent glycerol and 30 min equilibration yielded the highest post-thaw sperm motility and head membrane integrity.Conclusion: Cynomolgus monkey spermatozoa can be successfully cryopreserved in a chemically defined extender,which is related to the concentration and the equilibration time of glycerol.展开更多
Liver cell transplantation presents clinical benefit in patients with inborn errors of metabolism as an alternative,or at least as a bridge,to orthotopic liver transplantation.The success of such a therapeutic approac...Liver cell transplantation presents clinical benefit in patients with inborn errors of metabolism as an alternative,or at least as a bridge,to orthotopic liver transplantation.The success of such a therapeutic approach remains limited by the quality of the transplanted cells.Cryopreservation remains the best option for long-term storage of hepatocytes,providing a permanent and sufficient cell supply.However, isolated adult hepatocytes are poorly resistant to such a process,with a significant alteration both at the morphological and functional levels.Hence,the aim of the current review is to discuss the state of the art regarding widely-used hepatocyte cryopreservation protocols,as well as the assays performed to analyse the post-thawing cell quality both in vitro and in vivo. The majority of studies agree upon the poor quality and efficiency of cryopreserved/thawed hepatocytes as compared to freshly isolated hepatocytes.Intracellular ice formation or exposure to hyperosmotic solutionsremains the main phenomenon of cryopreservation process,and its effects on cell quality and cell death induction will be discussed.The increased knowledge and understanding of the cryopreservation process will lead to research strategies to improve the viability and the quality of the cell suspensions after thawing.Such strategies,such as vitrification,will be discussed with respect to their potential to significantly improve the quality of cell suspensions dedicated to liver cell-based therapies.展开更多
Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m^-2 s^-...Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m^-2 s^-1 for 3 weeks were encapsulated in calcium alginate beads. The beads were dehydrated in 0.4 molLl sucrose prepared with seawater for 6 h, desiccated in an incubator set at 10℃ and 70% relative humidity for 4 h, pre-frozen at either -40℃ or -60℃ for 30 min, and stored in liquid nitrogen for 〉24 h. As high as 43% of survival rate was observed when gametophytes were thawed by placing the beads in 40℃ seawater and re-hydrated in 0.05 molL^-1 citrate sodium prepared using 30‰ NaCl 7 d later. More cells of male gametophytes survived the whole procedure in comparison with female gametophytes. The cells of gametophytes surviving the preservation were able to grow asexually and produce morphologically normal sporophytes.展开更多
AIM To demonstrate the feasibility of cryopreservation of peripheral blood mononuclear cells(PBMCs) for prognostic circulating tumor cell(CTC) detection in gastroesophageal cancer.METHODS Using 7.5 m L blood samples c...AIM To demonstrate the feasibility of cryopreservation of peripheral blood mononuclear cells(PBMCs) for prognostic circulating tumor cell(CTC) detection in gastroesophageal cancer.METHODS Using 7.5 m L blood samples collected in EDTA tubes from patients with gastroesopheagal adenocarcinoma, CTCs were isolated by epithelial cell adhesion molecule based immunomagnetic capture using the Iso Flux platform. Paired specimens taken during the same blood draw(n = 15) were used to compare number of CTCs isolated from fresh and cryopreserved PBMCs. Blood samples were processed within 24 h to recover the PBMC fraction, with PBMCs used for fresh analysis immediately processed for CTC isolation. Cryopreservation of PBMCs lasted from 2 wk to 25.2 mo(median 14.6 mo). CTCs isolated from pre-treatment cryopreserved PBMCs(n = 43) were examined for associations with clinicopathological variables and survival outcomes.RESULTS While there was a significant trend to a decrease in CTC numbers associated with cryopreserved specimens(mean number of CTCs 34.4 vs 51.5, P = 0.04), this was predominately in samples with a total CTC count of > 50, with low CTC count samples less affected(P = 0.06). There was no significant association between the duration of cryopreservation and number of CTCs. In cryopreserved PBMCs from patient samples prior to treatment, a high CTC count(> 17) was associated with poorer overall survival(OS)(n = 43, HR = 4.4, 95%CI: 1.7-11.7, P = 0.0013). In multivariate analysis, after controlling for sex, age, stage, ECOG performance status, and primary tumor location, a high CTC count remained significantly associated with a poorer OS(HR = 3.7, 95%CI: 1.2-12.4, P = 0.03). CONCLUSION PBMC cryopreservation for delayed CTC isolation is a valid strategy to assist with sample collection, transporting and processing.展开更多
Cryodamages occur during sperm cryopreservation. Cryopreservation of fish sperm usually results in marked decrease in sperm quality, such as swelling or disruption of the plasma membrane, mi-tochondrial dysfunction, d...Cryodamages occur during sperm cryopreservation. Cryopreservation of fish sperm usually results in marked decrease in sperm quality, such as swelling or disruption of the plasma membrane, mi-tochondrial dysfunction, diminished sperm motility, impaired velocity, shorter motility period, denatura-tion, and release of some enzymes from spermatozoa. In this paper, damages in morphology, physiology, biochemistry and metabolism, and genetic integrity of fish semen after cryopreservation are discussed. New approaches in assessment of fish thawed sperm quality such as computer assisted sperm analysis, flow cytometic analysis combined with fluorescent probes and single cell gel electrophoresis are also briefly reviewed.展开更多
Low-density lipoprotein (LDL) extracted from hen egg yolk has recently been considered to be superior to whole egg yolk in sperm cryopreservation of various animal species. Meanwhile, there was a notion that high-de...Low-density lipoprotein (LDL) extracted from hen egg yolk has recently been considered to be superior to whole egg yolk in sperm cryopreservation of various animal species. Meanwhile, there was a notion that high-density lipoprotein (HDL) in egg yolk may have a negative effect on post-thaw survival. The role of LDL and HDL in sperm cryopreservation of rhesus monkeys has not been explored. The present study evaluates their effect in comparison with egg yolk with or without the addition of permeable cryoprotectant (glycerol) on sperm cryopreservation of rhesus macaques. In addition, various additives intended to change the lipid composition of LDL-sperm membrane complex have also been tested for their effectiveness in preserving post-thaw viability. Our findings indicated that LDL is the main component in egg yolk that is responsible for its protective role for sperm cryopreservation in rhesus monkeys. Regardless of the presence or absence of glycerol, the protective role of LDL is similar to that of egg yolk and we did not observe any superiority in post-thaw survival with LDL when compared to egg yolk. Modifying the lipid composition of LDL-sperm membrane complex with the addition of cholesterol, cholesterol loaded cyclodextrin and phosphatidylcholine also did not yield any improvements in pest-thaw survival; while addition of methyl-β-cyclodextrin reduced post-thaw motility. HDL plays a neutral role in sperm cryopreservation of rhesus monkeys. The present study suggests that egg yolk may still hold advantages when compared with LDL as effective components in extenders for sperm cryopreservation in rhesus monkeys.展开更多
Cell cryopreservation has evolved as an important technology required for supporting various cell-based applications,such as stem cell therapy,tissue engineering,and assisted reproduction.Recent times have witnessed a...Cell cryopreservation has evolved as an important technology required for supporting various cell-based applications,such as stem cell therapy,tissue engineering,and assisted reproduction.Recent times have witnessed an increase in the clinical demand of these applications,requiring urgent improvements in cell cryopreservation.However,cryopreservation technology suff ers from the issues of low cryopreservation effi ciency and cryoprotectant(CPA)toxicity.Application of advanced biotechnology tools can signifi cantly improve post-thaw cell survival and reduce or even eliminate the use of organic solvent CPAs,thus promoting the development of cryopreservation.Herein,based on the diff erent cryopreservation mechanisms available,we provide an overview of the applications and achievements of various biotechnology tools used in cell cryopreservation,including trehalose delivery,hydrogel-based cell encapsulation technique,droplet-based cell printing,and nanowarming,and also discuss the associated challenges and perspectives for future development.展开更多
The changes in the cell ultrastructure of in vitro cultured shoot tips from dwarf genotype of kiwifruit (Actinidia chinensis Ganmi 5) during cryopreservation were investigated. Shoot tips were preserved in liquid ni...The changes in the cell ultrastructure of in vitro cultured shoot tips from dwarf genotype of kiwifruit (Actinidia chinensis Ganmi 5) during cryopreservation were investigated. Shoot tips were preserved in liquid nitrogen using vitrification, and the cell ultrastructure was examined using transmission electron microscopy (TEM). The regular ultrastructure of the cell wall, cell membrane and nucleus of shoot tips could be damaged during the freezing and thawing associated with preservation using liquid nitrogen. The cell plasmolysis was increased and freezing tolerance was improved after precultufing and dehydrating in a preservation and vitrification solution (PVS2) (30% glycerol (Gly)+ 15% ethylene glycol (EG)+ 15% dimethylsulfoxide (DMSO) + 0.4 mol L^-1 sucrose). The structure of some cells with low degree of injury and reversible damage was similar to that of the control and they could undergo normal cell division and differentiation. Besides, they could recover automatically and regenerate after their reculture.展开更多
Sucrose is known to play an important role in the cryopreservation of sperm and female gonads; however, its effect on the cryopreservation ofpig spermatogonial stem cells (pSSCs) has not been tested. The aim of this...Sucrose is known to play an important role in the cryopreservation of sperm and female gonads; however, its effect on the cryopreservation ofpig spermatogonial stem cells (pSSCs) has not been tested. The aim of this work was to study the effect of sucrose during pSSC cryopreservation and to find the most effective concentration in freezing medium, pSSCs were cryopreserved with freezing media containing different concentrations of sucrose (70, 140, 210, and 280 mmol L^-1) and a control group without sucrose. The survival rates, plasma membrane integrity, and mitochondrial membrane potential of thawed cells were detected by trypan blue (TB) staining, SYBR-14/propidium iodide (PI) dual staining, and JC-1 staining, respectively. All the staining results showed an obvious increase in cell survival in the sucrose-treated groups as compared to that in the control group, with the exception of 280 mmol L^-1 sucrose. Moreover, the 210 mmol L^-1 sucrose group yielded the highest survival rate among all the groups (P〈0.05). The results of SYBR-14/PI dual staining and JC-1 staining were consistent with those of TB staining as above described. Quantitative real-time PCR (qRT-PCR) indicated that the mRNA levels of three apoptosis-promoting genes (BAX, APAF1 and CASPASE9) were significantly higher in thawed cells than in cells before freezing (P〈0.05). Moreover, the mRNA level of one anti-apoptotic gene (XIAP) was significantly lower in thawed cells than in cells before freezing (P〈0.05). When comparing the mRNA expression of apoptosis-related genes in thawed cells, the mRNA level of the anti-apoptotic genes in the control group was significantly lower than that in the sucrose-treated groups (P〈0.05). Western blot analyses showed that the expression levels of cleaved CASPASE9, CASPASE3 and PARP-1 in the sucrose-treated groups were lower than those in the control group and were the lowest in the 210 mmol L-1 sucrose group. Both qRT-PCR and Western blot analyses suggested that sucrose inhibited cell apoptosis during freezing and thawing. Briefly, sucrose promoted pSSCs survival after freezing and thawing, especially at a concentration of 210 mmol L^-1, which possibly assisted pSSC dehydration and inhibited cell apoptosis. These findings hold great promise for further studies of the regulatory mechanism of proliferation and differentiation of pSSCs.展开更多
In vertebrates, most somatosensory pathways begin with the activation of dorsal root ganglion(DRG) neurons. The development of an appropriate DRG culture method is a prerequisite for establishing in vitro peripheral n...In vertebrates, most somatosensory pathways begin with the activation of dorsal root ganglion(DRG) neurons. The development of an appropriate DRG culture method is a prerequisite for establishing in vitro peripheral nerve disease models and for screening therapeutic drugs. In this study, we compared the changes in morphology, molecular biology, and transcriptomics of chicken embryo DRG cultured on tissue culture plates(T-DRG) versus three-dimensional collagen hydrogels(C-DRG). Our results showed that after 7 days of culture, the transcriptomics of T-DRG and C-DRG were quite different. The upregulated genes in C-DRG were mainly related to neurogenesis, axon guidance, and synaptic plasticity, whereas the downregulated genes in C-DRG were mainly related to cell proliferation and cell division. In addition, the genes related to cycles/pathways such as the synaptic vesicle cycle, cyclic adenosine monophosphate signaling pathway, and calcium signaling pathway were activated, while those related to cell-cycle pathways were downregulated. Furthermore, neurogenesis-and myelination-related genes were highly expressed in C-DRG, while epithelial–mesenchymal transition-, apoptosis-, and cell division-related genes were suppressed. Morphological results indicated that the numbers of branches, junctions, and end-point voxels per C-DRG were significantly greater than those per T-DRG. Furthermore, cells were scattered in T-DRG and more concentrated in C-DRG, with a higher ratio of 5-ethynyl-2′-deoxyuridine(EdU)-positive cells in T-DRG compared with C-DRG. C-DRG also had higher S100 calcium-binding protein B(S100 B) and lower α-smooth muscle actin(α-SMA) expression than T-DRG, and contained fewer terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)-positive cells after 48 hours of serum starvation. After cryopreservation, C-DRG maintained more intact morphological characteristics, and had higher viability and less TUNEL-positive cells than T-DRG. Furthermore, newly formed nerve bundles were able to grow along the existing Schwann cells in C-DRG. These results suggest that C-DRG may be a promising in vitro culture model, with better nerve growth and anti-apoptotic ability, quiescent Schwann cells, and higher viability. Results from this study provide a reference for the construction, storage, and transportation of tissue-engineered nerves. The study was approved by the Ethics Committee of Aier School of Ophthalmology, Central South University, China(approval No. 2020-IRB16), on March 15, 2020.展开更多
基金the National Natural Science Foundation of China(No.82172114)the Anhui Provincial Natural Science Foundation for Distinguished Young Scholars(No.2108085J37).
文摘Cryopreservation of red blood cells(RBCs)provides great potential benefits for providing transfusion timely in emergencies.High concentrations of glycerol(20%or 40%)are used for RBC cryopreservation in current clinical practice,which results in cytotoxicity and osmotic injuries that must be carefully controlled.However,existing studies on the low-glycerol cryopreservation of RBCs still suffer from the bottleneck of low hematocrit levels,which require relatively large storage space and an extra concentration process before transfusion,making it inconvenient(time-consuming,and also may cause injury and sample lose)for clinical applications.To this end,we develop a novel method for the glycerol-free cryopreservation of human RBCs with a high final hematocrit by using trehalose as the sole cryoprotectant to dehydrate RBCs and using core–shell alginate hydrogel microfibers to enhance heat transfer during cryopreservation.Different from previous studies,we achieve the cryopreservation of human RBCs at high hematocrit(>40%)with high recovery(up to 95%).Additionally,the washed RBCs post-cryopreserved are proved to maintain their morphology,mechanics,and functional properties.This may provide a nontoxic,high-efficiency,and glycerol-free approach for RBC cryopreservation,along with potential clinical transfusion benefits.
基金supported by the National Natural Science Foundation of China(22078238,U23B20121)。
文摘Ligament cryopreservation enables a prolonged shelf life of allogeneic ligament grafts,which is fundamentally important to ligament reconstruction.However,conventional cryopreservation techniques fail to eliminate the damage caused by ice crystal growth and the toxicity of cryopreservation agents(CPAs).Here,we report a novel CPA vitrification formulation primarily composed of betaine for ligament cryopreservation.Comprehensive optimization was conducted on the methods for vitrification and rewarming,as well as the loading and unloading conditions,based on the critical cooling rate(CCR),critical warming rate(CWR),and permeation properties of the CPA.Using biomechanical and histological level tests,we demonstrate the superior performance of our method in ligament cryopreservation.After 30 days of vitrification cryopreservation,parameters such as the Young's modulus,tensile stress,denaturation temperature,and glycosaminoglycans content of the ligament remained essentially unchanged.This work pioneers the application of ice-free cryopreservation for ligament and holds great potential for improving the long-term storage of ligament,providing valuable insights for future cryopreservation technique development.
文摘Teratozoospermia is an infertility issue that affects a significant number of couples of reproductive age. One of the potential causes contributing to the global decline in seminal quality includes factors such as diet, alcohol and tobacco consumption, high levels of stress, and environmental influences. This underscores the need to preserve the fertility of these patients through cryopreservation techniques. In this review, we explore the latest methods for freezing seminal samples, highlighting their advancements and advantages in addressing the challenge of perpetuating animal species, particularly in the context of human infertility.
文摘Preserving microbial diversity has become a strategic undertaking. Thus, ex situ microalgal culture conservation results in strategic and functional resource in both biodiversity protection and application domains. Cryopreservation of microalgae has been practiced since the 1960s and is now considered the optimal preservation strategy. Furthermore, the overall monitoring during growth of cultures after freezing/thawing protocols was hardly investigated and there is poor evaluation related to preserve especially the photosystem apparatus. The present study focuses on Stichococcus bacillaris as case study for short-term cryopreservation at −80 °C storage. Various freezing pretreatments using cryoprotective agents, and two thawing methods were compared introducing a novel variable to evaluate viability recovery and assessing growth kinetics of cultures immediately after thawing and after a series batch cultivation. Photosynthetic rate and pigments assessment were proposed to evaluate hidden metabolic cell damage. Results underline cryoprotective agents can increase the kinetic recovery of preserved cells in terms of reduction of lag phase during batch cultivation tests: the use of dimethyl sulfoxide and glycerol granted a growth comparable to unpreserved cells when sudden thawing occurs after 24 hours of storage, but recovery after preservation is less sensitive to cryoprotective agents when gradual thawing and 1 month of storage is considered. However, cells are always able to restore their physiological pathways even without agents, so their kinetic effect has been proved and quantified. Interestingly, both the photosynthetic efficiency and the ratio between total chlorophyll and carotenoids are comparable (0.75 F<sub>v</sub>/F<sub>m</sub>, 2.2 ± 0.25 g/g) to unpreserved cells and they are unsensitive to chosen agents, but the ratio between chlorophyll a and chlorophyll b was clearly altered (up to 10 times), suggesting that photoactive pigments relative proportions can result in similar growth kinetic performances. Long-term studies will be carried out to assess whether the differences found could cause chronic damage to photosystem efficiency of S. bacillaris cultures.
基金Financial support of this study was provided by National Key R&D Program of China(No.2021YFD1200301 and 2021YFD1200305)joint research project raised by National Natural Science Foundation of China and The Egyptian Academy of Scientific Research and Technology(No.31961143028)+1 种基金China Agriculture Research Systems(No.CARS-40)National Germplasm Bank of Domestic Animals(No.2021–2022)。
文摘Poultry genetics resources,including commercial selected lines,indigenous breeds,and experimental lines,are now being irreversibly lost at an alarming rate due to multiple reasons,which further threats the future livelihood and academic purpose.Collections of germplasm may reduce the risk of catastrophic loss of genetic diversity by guaranteeing that a pool of genetic variability is available to ensure the reintroduction and replenishment of the genetic stocks.The setting up of biobanks for poultry is challenging because the high sensitiveness of spermatozoa to freezing–thawing process,inability to cryopreserve the egg or embryo,coupled with the females being heterogametic sex.The progress in cryobiology and biotechnologies have made possible the extension of the range of germplasm for poultry species available in cryobanks,including semen,primordial germ cells,somatic cells and gonads.In this review,we introduce the state-of-the-art technologies for avian genetic resource conservation and breed reconstruction,and discuss the potential challenges for future study and further extending of these technologies to ongoing and future conservation efforts.
文摘For men with severe oligozoospermia, sperm cryopreservation can preserve surgically obtained sperm. How to cryopreserve single sperm in men is still a hot topic in assisted reproduction technology. Aim to analyze the laboratory and pregnancy outcomes of single sperm cryopreservation group, we retrospectively selected 38 cycles underwent single sperm cryopreservation and thawing as the study group and 618 cycles underwent conventional sperm cryopreservation and thawing as the control group, which were performed in the reproductive medicine center of the Sixth Affiliated Hospital, Sun Yatsen University, from April 2014 to October 2023. All the sperm came from microdissection testicular sperm extraction (micro-TESE), and performed intracytoplasmic sperm injection (ICSI) for fertilization. Zygotes were cultured to Day 3 embryo, which were freshly transferred to female uterus. Surplus embryos were cultured to blastosphere and cryopreserved. There was no statistical difference in female/male age, female BMI, infertility duration and female basal sex hormone (FSH, LH E2, AMH), No. of oocytes retrieved per cycle, No. of ICSI oocytes per cycle and No. of embryos transferred per cycle between the two groups (P > 0.05). No significant difference was found in two-pronuclear oocyte fertilization rate (59.23% VS 58.84%), Day 3 available embryo rate (61.81% VS 63.55%), Day 3 good-quality embryo rate (45.73% VS 50.27%), blastocyst formation rate (47.83% VS 49.46%), the implantation rate (47.37% VS 52.16%), clinical pregnancy rate (36.84% VS 47.18%), miscarriage rate (14.29% VS 12.68%) and live birth rate (85.71% VS 81.70%) between two groups (P > 0.05). In conclusion, single-sperm cryopreservation was the optimal method to preserve sperm after micro-TESE. It can increase the utilization of each sperm and lead to clinical pregnancy.
文摘Cryopreservation is currently the only effective tool for long-term storage of semen in most species. However, it is well-recognized that, even in species that freeze well, some individuals resist cryopreservation. Work from this laboratory has demonstrated a relationship between maternal lipid content and the chemical constitution of the embryos they produce. The objective of the present study was to determine if a similar relationship might exist in paternal body chemistry and the animal’s semen sample and if such a difference could be determined with a simple weight test. Semen samples were obtained from cattle with known differences in body composition. The samples first underwent semen analysis and were then prepared as either cell-free (CF) or neat specimens (NS). Known volumes of each sample were weighed, and the remainder of the samples was analyzed for lipids, total proteins, and total carbohydrates using a series of spectrophotometric assays and blood chemistry techniques. As expected, weight differences were seen in the CF vs NS preparations of individual semen samples (p < 0.001). Differences were also found in triglycerides (p < 0.001), glucose (p < 0.001), total protein (p < 0.001), and fructose (p < 0.009) of individuals with differing body composition. Statistical analysis suggested a non-linear correlation between the observed weights and total protein (p < 0.047) as well as triglyceride levels (p < 0.003). Together, these data suggest it might be possible to develop an algorithm to allow adjustment in cryoprotectants based on a simple weight procedure, allowing modification of cryoprotectants on an individual basis and potentially improving outcomes for valuable animals currently classified as “poor freezers”.
基金Supported by National Natural Science Foundation of China(30801353)Shandong Education Department Foundation Project(G08LG53)~~
文摘[Objective] The aim of this study was to establish the in vitro culture system of chicken fibroblasts.[Method] Tissue explant method and enzymatic digestion method were used to separate and culture chicken skin fibroblasts respectively.The rate of cell growth,cryopreservation and recovery were compared.[Result] The primary chicken fibroblasts prepared by enzymatic digestion grew faster and converged together to form monolayer on 5 d post preparation;the passage cells prepared by these 2 methods grew at similar speed and formed monolayer within 2-3 d;homogeneous fibroblasts could be obtained by trypsin digestion and repeated attachment for 3-4 passages;there were 75%-80% of cells survived after cryopreservation and recovery;the growth curves of embryonic fibroblasts and skin fibroblasts were all normal and the two kind of cells still retained the normal number of chromosomes even at the twelfth passage.[Conclusion] The feeder layer cells needed for establishing ES cell lines could be obtained by culturing chicken fibroblasts through both tissue explant method and enzymatic digestion method.This study provided a basis for the successful establishment of ES cell lines.
文摘Embryo cryopreservation(CP) has became a very important part of the clinical use of in vitro fertilization. Oocyte CP offers more advantages compared with embryo freezing with regard to less ethical, legal and moral problems. However, the efficiency of this procedure is still low, which prevents its clinical application in wide range. The aim of our paper is to review the basic principles, technical and safety aspects and current status of oocyte cryopreservation in human assisted reproduction.
基金Natural Science Foundation of Jiangsu Province (BK2008589)Qing Lan Project of Jiangsu ProvinceCooperation Project of Agricultural Production, Study and Research in Wuxi City~~
文摘[Objective] This study aimed to investigate the effects of cryopreservation on the quality and ultrastructure of Tibetan Mastiff sperm. [Method] The effects of cryopreservation on the quality of Tibetan Mastiff sperm were evaluated via motility, membrane integrity rate and acrosome intact rate. On that basis, the effects of cryopreservation on ultrastructure of sperm were observed under SEM and TEM. [Result] In Experiment 1, EG gave the best results not only in post-thaw motility rate (36.3%), but also in low membrane integrity rate (38.0%) and acrosome intact rate (42.0% ), but there was no significant difference between EG group and Glycerol group (P0.05). In Experiment 2, the 5 cm freezing height obtained the best freezing-thawing results, but there was no significant difference between 2 and 5 cm height (P 0.05), besides in acrosome intact rate. In Experiment 3, SDS and Vc added separately or together into extenders could improve freezing-thawing results, but there was not obvious difference between SDS group and Vc group (P0.05), besides the lower motility of Vc group (P0.05). Addition of SDS and Vc obtained the best results in post-thaw motility rate (44.1%), and also in membrane integrity rate (48.0%) and acrosome intact rate (48.2%). The ultrastructure of frozen-thawed sperm was also evaluated under SEM and TEM, results showed that cryopreservation caused various degrees of damage to Tibetan Mastiff sperm, more serious damages were observed in the acrosome such as swelling, vesiculation and even disappearance. [Conclusion] This study confirms that EG, horizontal height of 0.25 ml straw above LN 2 surface and additives SDS and Vc together can improve freezing effect. However, cryopreservation has certain damage to ultrastructure of sperm.
文摘Aim:To establish a method for cynomolgus monkey sperm cryopreservation in a chemically defined extender. Methods:Semen samples were collected by electro-ejaculation from four sexually mature male cynomolgus monkeys. The spermatozoa were frozen in straws by liquid nitrogen vapor using egg-yolk-free Tes-Tris (mTTE) synthetic extender and glycerol as cryoprotectant.The effects of glycerol concentration (1%,3 %,5 %,10 % and 15 % [v/v]) and its equilibration time (10 min,30 min,60 min and 90 min) on post-thaw spermatozoa were examined by sperm motility and sperm head membrane integrity.Results:The post-thaw motility and head membrane integrity of spermatozoa were significantly higher (P<0.05) for 5 % glycerol (42.95±2.55 and 50.39±2.42,respectively) than those of the other groups (1%:19.19±3.22 and 24.84±3.64;3 %:34.23±3.43 and 41.37±3.42;10 %: 15.68±2.36 and 21.39±3.14;15 %:7.47±1.44 and 12.90±2.18).The parameters for 30 min equilibration (42.95±2.55 and 50.39±2.42) were better (P<0.05) than those of the other groups (10 min:31.33±3.06 and 38. 98±3.31;60 min:32.49±3.86 and 40.01±4.18;90 min:31.16±3.66 and 38.30±3.78).Five percent glycerol and 30 min equilibration yielded the highest post-thaw sperm motility and head membrane integrity.Conclusion: Cynomolgus monkey spermatozoa can be successfully cryopreserved in a chemically defined extender,which is related to the concentration and the equilibration time of glycerol.
基金Supported by The Belgian National Fund for Medical Research, the Région Wallonne-DGTRE(Grant WALEO/HEPATERA) and "La Fondation St Luc-ARC Thérapie Cellulaire"Stéphenne Xis recipient of a Grant-FNRS for cell cryopreservation
文摘Liver cell transplantation presents clinical benefit in patients with inborn errors of metabolism as an alternative,or at least as a bridge,to orthotopic liver transplantation.The success of such a therapeutic approach remains limited by the quality of the transplanted cells.Cryopreservation remains the best option for long-term storage of hepatocytes,providing a permanent and sufficient cell supply.However, isolated adult hepatocytes are poorly resistant to such a process,with a significant alteration both at the morphological and functional levels.Hence,the aim of the current review is to discuss the state of the art regarding widely-used hepatocyte cryopreservation protocols,as well as the assays performed to analyse the post-thawing cell quality both in vitro and in vivo. The majority of studies agree upon the poor quality and efficiency of cryopreserved/thawed hepatocytes as compared to freshly isolated hepatocytes.Intracellular ice formation or exposure to hyperosmotic solutionsremains the main phenomenon of cryopreservation process,and its effects on cell quality and cell death induction will be discussed.The increased knowledge and understanding of the cryopreservation process will lead to research strategies to improve the viability and the quality of the cell suspensions after thawing.Such strategies,such as vitrification,will be discussed with respect to their potential to significantly improve the quality of cell suspensions dedicated to liver cell-based therapies.
文摘Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10℃ and under continuous irradiance of 30 μmol m^-2 s^-1 for 3 weeks were encapsulated in calcium alginate beads. The beads were dehydrated in 0.4 molLl sucrose prepared with seawater for 6 h, desiccated in an incubator set at 10℃ and 70% relative humidity for 4 h, pre-frozen at either -40℃ or -60℃ for 30 min, and stored in liquid nitrogen for 〉24 h. As high as 43% of survival rate was observed when gametophytes were thawed by placing the beads in 40℃ seawater and re-hydrated in 0.05 molL^-1 citrate sodium prepared using 30‰ NaCl 7 d later. More cells of male gametophytes survived the whole procedure in comparison with female gametophytes. The cells of gametophytes surviving the preservation were able to grow asexually and produce morphologically normal sporophytes.
文摘AIM To demonstrate the feasibility of cryopreservation of peripheral blood mononuclear cells(PBMCs) for prognostic circulating tumor cell(CTC) detection in gastroesophageal cancer.METHODS Using 7.5 m L blood samples collected in EDTA tubes from patients with gastroesopheagal adenocarcinoma, CTCs were isolated by epithelial cell adhesion molecule based immunomagnetic capture using the Iso Flux platform. Paired specimens taken during the same blood draw(n = 15) were used to compare number of CTCs isolated from fresh and cryopreserved PBMCs. Blood samples were processed within 24 h to recover the PBMC fraction, with PBMCs used for fresh analysis immediately processed for CTC isolation. Cryopreservation of PBMCs lasted from 2 wk to 25.2 mo(median 14.6 mo). CTCs isolated from pre-treatment cryopreserved PBMCs(n = 43) were examined for associations with clinicopathological variables and survival outcomes.RESULTS While there was a significant trend to a decrease in CTC numbers associated with cryopreserved specimens(mean number of CTCs 34.4 vs 51.5, P = 0.04), this was predominately in samples with a total CTC count of > 50, with low CTC count samples less affected(P = 0.06). There was no significant association between the duration of cryopreservation and number of CTCs. In cryopreserved PBMCs from patient samples prior to treatment, a high CTC count(> 17) was associated with poorer overall survival(OS)(n = 43, HR = 4.4, 95%CI: 1.7-11.7, P = 0.0013). In multivariate analysis, after controlling for sex, age, stage, ECOG performance status, and primary tumor location, a high CTC count remained significantly associated with a poorer OS(HR = 3.7, 95%CI: 1.2-12.4, P = 0.03). CONCLUSION PBMC cryopreservation for delayed CTC isolation is a valid strategy to assist with sample collection, transporting and processing.
基金Funded by the National High Technology R&D Program of China (863 Program, Nos. 2001AA621100, 2003AA603510 and 2004AA603310).
文摘Cryodamages occur during sperm cryopreservation. Cryopreservation of fish sperm usually results in marked decrease in sperm quality, such as swelling or disruption of the plasma membrane, mi-tochondrial dysfunction, diminished sperm motility, impaired velocity, shorter motility period, denatura-tion, and release of some enzymes from spermatozoa. In this paper, damages in morphology, physiology, biochemistry and metabolism, and genetic integrity of fish semen after cryopreservation are discussed. New approaches in assessment of fish thawed sperm quality such as computer assisted sperm analysis, flow cytometic analysis combined with fluorescent probes and single cell gel electrophoresis are also briefly reviewed.
基金This work was supported in part by funding from the National Natural Science Foundation of China (No. 30800845), the Natural Science Fund for Distinguished Young Scholars of Zhejiang Province (No. R3100105), and the NIH grants RR00169 and RR13439. We thank Dr. M. Anton for providing the detailed protocols of LDL and HDL extraction.
文摘Low-density lipoprotein (LDL) extracted from hen egg yolk has recently been considered to be superior to whole egg yolk in sperm cryopreservation of various animal species. Meanwhile, there was a notion that high-density lipoprotein (HDL) in egg yolk may have a negative effect on post-thaw survival. The role of LDL and HDL in sperm cryopreservation of rhesus monkeys has not been explored. The present study evaluates their effect in comparison with egg yolk with or without the addition of permeable cryoprotectant (glycerol) on sperm cryopreservation of rhesus macaques. In addition, various additives intended to change the lipid composition of LDL-sperm membrane complex have also been tested for their effectiveness in preserving post-thaw viability. Our findings indicated that LDL is the main component in egg yolk that is responsible for its protective role for sperm cryopreservation in rhesus monkeys. Regardless of the presence or absence of glycerol, the protective role of LDL is similar to that of egg yolk and we did not observe any superiority in post-thaw survival with LDL when compared to egg yolk. Modifying the lipid composition of LDL-sperm membrane complex with the addition of cholesterol, cholesterol loaded cyclodextrin and phosphatidylcholine also did not yield any improvements in pest-thaw survival; while addition of methyl-β-cyclodextrin reduced post-thaw motility. HDL plays a neutral role in sperm cryopreservation of rhesus monkeys. The present study suggests that egg yolk may still hold advantages when compared with LDL as effective components in extenders for sperm cryopreservation in rhesus monkeys.
文摘Cell cryopreservation has evolved as an important technology required for supporting various cell-based applications,such as stem cell therapy,tissue engineering,and assisted reproduction.Recent times have witnessed an increase in the clinical demand of these applications,requiring urgent improvements in cell cryopreservation.However,cryopreservation technology suff ers from the issues of low cryopreservation effi ciency and cryoprotectant(CPA)toxicity.Application of advanced biotechnology tools can signifi cantly improve post-thaw cell survival and reduce or even eliminate the use of organic solvent CPAs,thus promoting the development of cryopreservation.Herein,based on the diff erent cryopreservation mechanisms available,we provide an overview of the applications and achievements of various biotechnology tools used in cell cryopreservation,including trehalose delivery,hydrogel-based cell encapsulation technique,droplet-based cell printing,and nanowarming,and also discuss the associated challenges and perspectives for future development.
文摘The changes in the cell ultrastructure of in vitro cultured shoot tips from dwarf genotype of kiwifruit (Actinidia chinensis Ganmi 5) during cryopreservation were investigated. Shoot tips were preserved in liquid nitrogen using vitrification, and the cell ultrastructure was examined using transmission electron microscopy (TEM). The regular ultrastructure of the cell wall, cell membrane and nucleus of shoot tips could be damaged during the freezing and thawing associated with preservation using liquid nitrogen. The cell plasmolysis was increased and freezing tolerance was improved after precultufing and dehydrating in a preservation and vitrification solution (PVS2) (30% glycerol (Gly)+ 15% ethylene glycol (EG)+ 15% dimethylsulfoxide (DMSO) + 0.4 mol L^-1 sucrose). The structure of some cells with low degree of injury and reversible damage was similar to that of the control and they could undergo normal cell division and differentiation. Besides, they could recover automatically and regenerate after their reculture.
基金supported by the China Postdoctoral Science Foundation(2014M560809)the Shaanxi Province Postdoctoral Science Foundation,China+1 种基金the Fundamental Research Funds for the Central Universities,China(NWSUAF,2452015145)the National Basic Research Program of China(2014CB943100)
文摘Sucrose is known to play an important role in the cryopreservation of sperm and female gonads; however, its effect on the cryopreservation ofpig spermatogonial stem cells (pSSCs) has not been tested. The aim of this work was to study the effect of sucrose during pSSC cryopreservation and to find the most effective concentration in freezing medium, pSSCs were cryopreserved with freezing media containing different concentrations of sucrose (70, 140, 210, and 280 mmol L^-1) and a control group without sucrose. The survival rates, plasma membrane integrity, and mitochondrial membrane potential of thawed cells were detected by trypan blue (TB) staining, SYBR-14/propidium iodide (PI) dual staining, and JC-1 staining, respectively. All the staining results showed an obvious increase in cell survival in the sucrose-treated groups as compared to that in the control group, with the exception of 280 mmol L^-1 sucrose. Moreover, the 210 mmol L^-1 sucrose group yielded the highest survival rate among all the groups (P〈0.05). The results of SYBR-14/PI dual staining and JC-1 staining were consistent with those of TB staining as above described. Quantitative real-time PCR (qRT-PCR) indicated that the mRNA levels of three apoptosis-promoting genes (BAX, APAF1 and CASPASE9) were significantly higher in thawed cells than in cells before freezing (P〈0.05). Moreover, the mRNA level of one anti-apoptotic gene (XIAP) was significantly lower in thawed cells than in cells before freezing (P〈0.05). When comparing the mRNA expression of apoptosis-related genes in thawed cells, the mRNA level of the anti-apoptotic genes in the control group was significantly lower than that in the sucrose-treated groups (P〈0.05). Western blot analyses showed that the expression levels of cleaved CASPASE9, CASPASE3 and PARP-1 in the sucrose-treated groups were lower than those in the control group and were the lowest in the 210 mmol L-1 sucrose group. Both qRT-PCR and Western blot analyses suggested that sucrose inhibited cell apoptosis during freezing and thawing. Briefly, sucrose promoted pSSCs survival after freezing and thawing, especially at a concentration of 210 mmol L^-1, which possibly assisted pSSC dehydration and inhibited cell apoptosis. These findings hold great promise for further studies of the regulatory mechanism of proliferation and differentiation of pSSCs.
基金supported by the National Natural Science Foundation of China,Nos.82000871(to ZKC),81871495(to JSC)the Natural Science Foundation of Hunan Province,China,No.2020JJ5001(to ZKC)+1 种基金the Science Research Grant of Aier Eye Hospital Group,China,No.AF1913D2(to ZKC)Central South University Postdoctoral Funds,China。
文摘In vertebrates, most somatosensory pathways begin with the activation of dorsal root ganglion(DRG) neurons. The development of an appropriate DRG culture method is a prerequisite for establishing in vitro peripheral nerve disease models and for screening therapeutic drugs. In this study, we compared the changes in morphology, molecular biology, and transcriptomics of chicken embryo DRG cultured on tissue culture plates(T-DRG) versus three-dimensional collagen hydrogels(C-DRG). Our results showed that after 7 days of culture, the transcriptomics of T-DRG and C-DRG were quite different. The upregulated genes in C-DRG were mainly related to neurogenesis, axon guidance, and synaptic plasticity, whereas the downregulated genes in C-DRG were mainly related to cell proliferation and cell division. In addition, the genes related to cycles/pathways such as the synaptic vesicle cycle, cyclic adenosine monophosphate signaling pathway, and calcium signaling pathway were activated, while those related to cell-cycle pathways were downregulated. Furthermore, neurogenesis-and myelination-related genes were highly expressed in C-DRG, while epithelial–mesenchymal transition-, apoptosis-, and cell division-related genes were suppressed. Morphological results indicated that the numbers of branches, junctions, and end-point voxels per C-DRG were significantly greater than those per T-DRG. Furthermore, cells were scattered in T-DRG and more concentrated in C-DRG, with a higher ratio of 5-ethynyl-2′-deoxyuridine(EdU)-positive cells in T-DRG compared with C-DRG. C-DRG also had higher S100 calcium-binding protein B(S100 B) and lower α-smooth muscle actin(α-SMA) expression than T-DRG, and contained fewer terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)-positive cells after 48 hours of serum starvation. After cryopreservation, C-DRG maintained more intact morphological characteristics, and had higher viability and less TUNEL-positive cells than T-DRG. Furthermore, newly formed nerve bundles were able to grow along the existing Schwann cells in C-DRG. These results suggest that C-DRG may be a promising in vitro culture model, with better nerve growth and anti-apoptotic ability, quiescent Schwann cells, and higher viability. Results from this study provide a reference for the construction, storage, and transportation of tissue-engineered nerves. The study was approved by the Ethics Committee of Aier School of Ophthalmology, Central South University, China(approval No. 2020-IRB16), on March 15, 2020.