China
Africa
Explore chapters and articles related to this topic
Synthetic Seeds Vis-A-Vis Cryopreservation: An Efficient Technique for Long-Term Preservation of Endangered Medicinal Plants
Published in Amit Baran Sharangi, K. V. Peter, Medicinal Plants, 2023
Md. Nasim Ali, Syandan Sinha Ray
On the contrary, cryopreservation is the most widely used method for long-term storage of germplasm under ex-situ condition at ultra-low temperature (–150 to –196°C) using liquid nitrogen (Chudhury and Malik, 2004). This is the only method to ensure the safe and cost-efficient long-term conservation of various types of plants (Engelmann, 2011). This method has been widely used for long time conservation because the metabolic activity of cells, cell divisions are ceased at an ultra-low temperature as well as there is no scope of any genetic modification which may happen during when they are maintained by serial subculturing (Cruz-Cruz et al., 2013). Optimum responses of plant propagules after cryopreservation are depending on the status of the plant, cryopreservation techniques and re-growth conditions (Uchendu and Reed, 2008). A convenient way of cryopreservation leads to the formation of ice and increases the solute concentration within the cell which causes cell damage. To counter this problem, cryoprotectants are used to reduce the amount of ice that crystallizes at any given temperature and thereby limit the solute concentration factor (Fahy et al., 1984).
Quality Control in Bone Marrow Processing
Published in Adrian P. Gee, BONE MARROW PROCESSING and PURGING, 2020
The most widely used cryoprotectant is dimethyl sulfoxide (DMSO), although it has not been formally approved by the FDA for this application (see Chapter 2). Adverse reactions to this agent can occur,5 particularly when large volumes are infused, e.g., in the case of peripheral blood stem cell transplants. Alternative freezing mixtures, in which the concentration of DMSO is reduced, have been developed (as described in this volume) and should be investigated where possible. The other components of the mixture consist of tissue culture medium and a protein source. Again, questions relating to the use of cell culture medium raised earlier in this article should be borne in mind. In particular, it is advisable to use indicator-free preparations, since there have been reports of adverse reactions to phenol red in transplant recipients.
Equine Semen Preservation: Current and Future Trends
Published in Juan Carlos Gardón, Katy Satué, Biotechnologies Applied to Animal Reproduction, 2020
Lydia Gil Huerta, Cristina Álvarez, Victoria Luño Lázaro
In the last years, long-storage alternatives sperm preservation methods simplest and cost-effective have been proposed in several species. One of them is sperm vitrification. This method preserves the spermatozoa in a hypertonic medium by plunging the cells directly into liquid nitrogen (Rall y Fahy, 1985). The advantages of vitrification are related to the low cost of equipment, simplicity, and low exposure time at low temperatures. However, it produces adverse effects due to the use of hypertonic solutions and high concentrations of cryoprotectants (Lopera et al., 2007).
Fecal microbiota transplantation: a review on current formulations in Clostridioides difficile infection and future outlooks
Published in Expert Opinion on Biological Therapy, 2022
Adèle Rakotonirina, Tatiana Galperine, Eric Allémann
To surpass the hurdle surrounding frozen FMT capsules and reduce the overall treatment volume, freeze-drying is a formulation enhancement. Briefly, freeze-drying, also known as lyophilization, consists of increasing sample stability by freezing the water it contains and removing it by sublimation. Several cryoprotectants can be used to reduce sample degradation. The main cryoprotectants can be classified as extracellular or as crossing or penetrating the cell membrane. Extracellular cryoprotectants generally possess a high molecular weight and limit the formation of intracellular crystals (e.g. starch). Cryoprotectants that cross or penetrate the cellular membrane limit cell dehydration, reduce its freezing point and diminish osmotic shock (e.g. amino acids, oligosaccharides, dimethylsulfoxide, glycerol) [88,89].
Perinatal outcome in children born after assisted reproductive technologies
Published in Upsala Journal of Medical Sciences, 2020
Ulla-Britt Wennerholm, Christina Bergh
Vitrification is an ultrarapid cryopreservation method, which instead of slow freezing has become the dominant method for cryopreservation in recent years. It has been associated with higher post-thaw survival rates and higher clinical pregnancy rates when compared with slow freezing (41,42). However, the high concentrations of cryoprotectants used for vitrification have raised concerns about possible negative health effects for the children. When comparing vitrification and slow freezing of day-3 embryos (43) or blastocysts (44), similar outcomes were found. A Nordic study compared vitrified blastocyst transfers with slow freezing day-2–3 embryo transfer (45). Except for a higher risk of preterm birth in the vitrified blastocyst group (aOR 1.33, 95% CI 1.09–1.62), there were no other differences. The higher risk of preterm birth was considered to be related to extended culture.
Optimization of composite cryoprotectant for freeze-drying Bifidobacterium bifidum BB01 by response surface methodology
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
He Chen, Mengqi Tian, Li Chen, Xiuxiu Cui, Jiangpeng Meng, Guowei Shu
The addition of cryoprotectants can reduce cell damage and cell death rate [21]. Single protective agent is not enough to protect the B. bifidum effectively; therefore, complex protective agents are required to improve the bacterial survival rate. It has been reported that 10 or 20% polysaccharide mixed with 10% skim milk exhibits the best protective effect against Bifidobacterium MYL16 [22]. Generally, the formulation of the protective agent depends on the cell structure. Response surface methodology (RSM) can be used to design, optimize and improve the protective agent combination which is time-saving and low cost [23,24]. Center composite design (CCD) is appropriate to study factors with three and/or five levels. The obtained results could fit with a nonlinear mathematical model and the equation expresses the relationship between the independent factors and the response values. The response values finally show the optimized cryoprotectant combination [25].