No abstract available.
Cryopreservation* ; Embryonic Stem Cells* ; Humans* ; Vitrification

Humans ; Vitrification ; Consensus ; Oocytes ; Fertilization in Vitro ; Cryopreservation

OBJECTIVE: This study was carried out to compare the effects of the stepwise exposure treatments on the morphological normality, fertilization and blastocyst formation rate of the frozen-thawed mouse mature oocytes by vitrification or ultra-rapid freezing and to use as a fundamental data for the cryopreservation of human oocytes. MATERIALS AND METHODS: The morphological normality and fertilization rates of the vitrified and ultra-rapid frozen mouse mature oocytes after three-stepwise exposure treatments (1step, 3step and 5step) were observed. After choosing the 3step exposure treatment groups, we observed the morphological normality and fertilization, blastocyst formation rate vitrified and ultra-rapid frozen mouse mature oocytes. RESULTS: The morphological normality and fertilization rates of the vitrified mouse mature oocytes after three-stepwise exposure treatments (1step, 3step and 5step) were 75%, 85%, 88% and 58%, 61%, 54% respectively. There were no significant differences among treatments (p>0.05). The morphological normality and fertilization rates of the control was 92% and 65%. There were no significant differences in fertilization rate among control and treatments (p>0.05). The morphological normality and fertilization rates of the ultra-rapid frozen mouse mature oocytes after three-stepwise exposure treatments (1step, 3step and 5step) were 83%, 83%, 84% and 75%, 63%, 56% respectively. There were no significant differences among treatments (p>0.05). The morphological normality and fertilization rate of the control was 95% and 67%. There were no significant differences among control and treatments (p>0.05). The morphological normality and fertilization rate of the vitrified or ultra-rapid frozen mouse mature oocytes after 3step exposure treatment were 69% and 75%, respectively. The blastocyst formation rate was 60% and 57%. The results did not differ significantly between vitrification and ultra-rapid freezing (p>0.05). CONCLUSION: As known in the above results, there were no significant differences in the fertilization and blastocyst formation rate of the frozen-thawed mouse mature oocytes by vitrification or ultra-rapid freezing among the control and treatments. It is suggested that vitrification and ultra-rapid freezing method were effective for the cryopreservation of mouse mature oocytes.
Animals ; Blastocyst ; Cryopreservation ; Fertilization ; Freezing* ; Humans ; Mice* ; Oocytes* ; Vitrification*

OBJECTIVE: The study was performed to compare the survival rate and the development of day 2 mouse embryos which had freezing procedures done. METHODS: We used three different vitrification solutions (EFS, VS14, DPS) and a ultrarapid freezing solution (UFS) for cryopreservation of day 2 mouse embryo. RESULTS: We tested toxicity by exposing embryos to vitrification solutions and a ultrarapid freezing solution. The survival rates are 100%, 97.8%, 95.6% and 100% (EFS, VS14, DPS and UFS). After cultured for 96 hours, hatching rates of each group are 93.5% (no freezing), 95.6% (EFS), 86.4% (VS14), 93.0% (DPS), and 93.0% (UFS). There is no significant differences among groups. The survival rates after thawing cryopreserved embryos are 80.2%, 91.7%, 69.5%, 0% and 91.8% (slow freezing, EFS, VS14, DPS and UFS). Also cultured for 96 hours, the hatching rates are 93.5% (no freezing), 84.1% (slow freezing), 93.9%) (EFS), 48.5% (VS14) and 70.1% (UFS). CONCLUSION:The survival rates of vitrification in EFS solution and ultrarapid freezing are higher than slow freezing (p<0.05). The hatching rate of vitrification in EFS solution cultured for 96 hours is highest, so vitrification of day 2 mouse embryos in EFS solution considered as more effective for cryopreservation.
Animals ; Cryopreservation ; Embryonic Structures* ; Freezing* ; Mice* ; Survival Rate ; Vitrification*

Bioreactors ; Cryopreservation ; methods ; Hepatocytes ; Humans ; Liver, Artificial ; Vitrification

OBJECTIVETo explore the feasibility and safety of microdrop-vitrification for epididymal spermatozoa obtained by percutaneous epididymal sperm aspiration (PESA) without cryoprotectants.

METHODSWe treated the epididymal sperm samples from 22 patients by conventional freezing (Group 1) and microdrop-vitrification without cryoprotectants (Group 2), and evaluated the effectiveness of the two methods by comparing their revival rate, retrieval rate and incidence of sperm nuclear DNA fractures.

RESULTSMotile sperm were found in all but 1 case in Group 1. The revival rates of the frozen sperm were low in both Groups 1 and 2 ([18.16 +/- 9.38]% vs [21.99 +/- 10.95]%, P > 0.05), but statistically significant differences were shown between the two groups in the retrieval rate ([58.39 +/- 12.67]% vs [70.82 +/- 14.94]%, P < 0.01). Before freezing, nuclear DNA fractures existed in the epididymal sperm samples of all the 22 patients, comet sperm were seen after unicellular gel electrophoresis, and the incidence of sperm nuclear DNA fracture was (26.68 +/- 9.45)%. After freezing, no increase was observed in the incidence of sperm nuclear DNA fracture in either Group 1 or 2 ([28.68 +/- 12.54]% vs [27.64 +/- 10.70]%, P > 0.05).

CONCLUSIONMicrodrop can be used as a suitable freezing carrier for a low number of sperm, and cryoprotectant-free vitrification with microdrop may be a simple, safe and effective method for the cryopreservation of a low number of epididymal sperm.

There is a great demand for blood and stem cells in clinic. It is difficult to achieve high throughput and to increase the cooling rate at the same time during vitrification. In this paper, a micro-droplet spray system with a container collection device was fabricated, and HepG2 cells were sprayed by this system for high-throughput vitrification. First, the container collection device and a cryo-paper were used to receive micro-droplets in the spray vitrification system. The results showed that the cell survival rate and 24h adhesion rate in container collection vitrification group were significantly higher than those in cryo-paper collection group. Second, HepG2 cells were sprayed and vitrified at increased cell density, and it was found that the results of micro-droplet spray vitrification did not change significantly. Finally, micro-droplet spray vitrification is compared with slow freezing. Cell processing capacity in the vitrification group increased, meanwhile, the cell survival rate and 24h adhesion rate in the vitrification group were significantly higher than those in slow freezing group. The results indicated that the micro-droplet spray vitrification system with container collection device designed in this paper can achieve high-throughput cell vitrification, which is of great significance for mass preservation of small cells.
Cell Adhesion ; Cell Survival ; Cryopreservation ; Hep G2 Cells ; Humans ; Vitrification

Oocyte cryopreservation is widely used for clinical and social reasons. Previous studies have demonstrated that conventional slow-freezing cryopreservation procedures, but not storage time, can alter the gene expression profiles of frozen oocytes. Whether vitrification procedures and the related frozen storage durations have any effects on the transcriptomes of human metaphase II oocytes remain unknown. Four women (30-32 years old) who had undergone IVF treatment were recruited for this study. RNA-Seq profiles of 3 fresh oocytes and 13 surviving vitrified-thawed oocytes (3, 3, 4, and 3 oocytes were cryostored for 1,2, 3, and 12 months) were analyzed at a single-cell resolution. A total of 1987 genes were differentially expressed in the 13 vitrified-thawed oocytes. However, no differentially expressed genes were found between any two groups among the 1-, 2-, 3-, and 12-month storage groups. Further analysis revealed that the aberrant genes in the vitrified oocytes were closely related to oogenesis and development. Our findings indicated that the effects of vitrification on the transcriptomes of mature human oocytes are induced by the procedure itself, suggesting that long-term cryostorage of human oocytes is safe.
Adult ; Cryopreservation ; Female ; Humans ; Metaphase ; Oocytes ; RNA-Seq ; Vitrification

Objective To investigate the effects of self-made carriers on the cryopreservation of ovarian tissue of sheep. Methods Thirty-two ovaries were randomly assigned to fresh group,programmed freezing group,self-made carrier I vitrification group,and self-made carrier Ⅱ vitrification group.The morphology,proliferation,apoptosis,and estrogen level of the ovarian tissue in each group were observed. Results After cryopreservation,the morphology normal rate of the primordial follicles in programmed freezing group,self-made carrier I vitrification group,and self-made carrier Ⅱ vitrification group were 74.2%,72.8%,and 72.3%,respectively,lower than that(83.7%)in the fresh group(χ
Animals ; Cryopreservation ; Female ; Freezing ; Ovarian Follicle ; Ovary ; Sheep ; Vitrification

OBJECTIVE: To find out the optimal freezing time in terms of developmental stage of mouse embryo and the effectiveness of vitrification method for freezing them. METHODS: Superovulation induction was performed using PMSG and hCG. Total 1,437 mouse embryos (vitrification group: 743, slow-freezing group: 694) were obtained and cultured with the T6 containing 0.4% BSA medium. Each developmental stage of embryos (1-, 2-, 4-, 8-cell, morula and blastocyst) were cryopreserved by vitrification and also by slow freezing method for comparison of the results. After thawing, the recovery rate, the survival rate and the blastocyst developmental rate were analysed and compared in two different settings. Student's t-test was used for statistical analysis. RESULTS: The survival and developmental rates at all subgroups of vitrification method are significantly higher than those of slow-freezing groups, but not in the recovery rates. In vitrification group, the survival rate and the blastocyst developmental rate are highest when frozen at morula stage, 98.4% and 86.4%, respectively. In slow-freezing group, the survival rate is also highest when frozen at morula stage, 87.2%, and the blastocyst developmental rate is highest when frozen at 8-cell stage, 78.1%. CONCLUSION: The vitrification method is more efficient for mouse embryo freezing compared with slow freezing one. Among various developmental stages of mouse embryos, morula stage seems to be the optimal stage for cryopreservation, whatever the freezing method applied. Therefore, we recommend embryo freezing at morula stage by vitrification method.
Animals ; Blastocyst ; Cryopreservation ; Embryonic Structures* ; Freezing ; Mice* ; Morula ; Superovulation ; Survival Rate ; Vitrification*