Explore chapters and articles related to this topic
The Journey of the Porcine Spermatozoa from Its Origin to the Fertilization Site: The Road In Vivo vs. In Vitro
Published in Juan Carlos Gardón, Katy Satué, Biotechnologies Applied to Animal Reproduction, 2020
Cristina Soriano-Úbeda, Francisco Alberto García-Vázquez, Carmen Matás
As discussed, under in vitro conditions, the pattern of sperm capacitation and fertilization is not similar to the situation in vivo. The media used in laboratories is not similar to OF and there is not a single medium commonly used in all laboratories that allows standardization of IVF in porcine (Coy et al., 2002). Chemically defined media are currently used for these techniques, with more or less complex composition based in salts, sugars, proteins such as albumin and other components. However, the media composition has not been able to equate with OF, as it is still unknown. In order to increase the performance of IVF in pigs, several protocols have been developed that include OF in the medium (Coy et al., 2010; Cánovas et al., 2017) although the lack of knowledge of OF composition remains a handicap in achieving consistency.
Embryonic Stem Cells
Published in Richard K. Burt, Alberto M. Marmont, Stem Cell Therapy for Autoimmune Disease, 2019
Dan S. Kaufman, James A. Thomson
Recently, the culture conditions required for growth of undifferentiated human ES cells have been refined. Whereas the original derivation of these cells used irradiated mouse embryonic fibroblast (MEF) feeder cells and media containing fetal bovine serum, it is now possible to grow these cells in serum-free media and on plates coated with either Matrigel® or laminin.25 Growth without feeder cells still requires “conditioned media” taken from cultures of MEFs. The requirement for “conditioned media” suggests that soluble factor(s) produced by the MEFs are essential for maintenance of undifferentiated ES cell growth. These refinements in the culture methods are the start of a process to identify the conditions that are essential for maintenance of human ES cell self-renewal. Eventually, use of a chemically defined media will aide in large-scale growth of human ES cells as a prelude to better cell-based therapies.
Tissue engineering and regeneration
Published in Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie, Bailey & Love's Short Practice of Surgery, 2018
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie
There is an enormous research effort aimed at better understanding the factors responsible for cell fate decisions, and establishing effective and reproducible protocols that can be used to differentiate stem cells in vitro into the desired type of specialised cell. Typically such protocols use culture in chemically defined media containing cocktails of small molecules that stimulate or inhibit key signalling pathways, along with cytokines, growth factors and chemicals. Many protocols include the addition of critical amounts of Activin, bone-morphogenetic protein-4 (BMP4) and fibroblast growth factor-2 (FGF2) at specific time points during culture, but protocols vary widely. For example, exposure of iPSCs to a combination of retinoic acid and BMP4 promotes differentiation along the ectoderm and then the keratinocyte lineage. Alternatively, culture of iPSCs on a Matrigel® scaffold in defined media supplemented with ascorbic acid and exposed sequentially to a glycogen synthase kinase (GSK) inhibitor followed by an inhibitor of Wnt signalling promotes the development of immature cardiomyocytes.
Effects of the green tea catechin epigallocatechin-3-gallate on Streptococcus mutans planktonic cultures and biofilms: systematic literature review of in vitro studies
Published in Biofouling, 2022
Maria Gerusa Brito Aragão, Carolina Patrícia Aires, Silmara Aparecida Milori Corona
Although several studies included in this systematic review showed that EGCG affects S. mutans susceptibility, a large discrepancy was found when comparing the reported MIC and MBC. Such differences might be ascribed to the use of different culture media as discussed by Xu et al. (2011), who found the lowest effective concentrations of EGCG to inhibit S. mutans. In this regard, Xu et al. (2011) investigated how EGCG affects the susceptibility of S. mutans in a chemically defined medium and BHI medium. The authors found a MIC 20 times higher in BHI when compared to chemically defined medium. The high protein content of BHI medium might interfere with the antimicrobial effect of EGCG once the proteins might bind to or precipitate this catechin (Xu et al. 2018). Moreover, the selected studies reported that higher concentrations of EGCG are needed to affect viability (>1,000 µg ml−1) (Sakanaka et al. 1989; Hirasawa et al. 2006; Han et al. 2021) and that such effects might be inhibited by sucrose (Hirasawa et al. 2006). In this regard, it is known that sucrose is a substrate for the synthesis of insoluble polysaccharides, which increase the virulence of S. mutans (Paes Leme et al. 2006) and might inhibit the effects of EGCG on growth and bacterial counts. Similar results have been demonstrated for xylitol and sorbitol, whose effects on S. mutans are suppressed in the presence of sucrose (Chan et al. 2020).
Human platelet lysates for human cell propagation
Published in Platelets, 2021
Lassina Barro, Pierre-Alain Burnouf, Ming-Li Chou, Ouada Nebie, Yu-Wen Wu, Ming-Sheng Chen, Miryana Radosevic, Folke Knutson, Thierry Burnouf
T-cell therapy involves a collection process of mononuclear cells by leukapheresis, their activation and genetic modification using viral vectors, followed by their expansion ex vivo for 9 ~ 11 days [103,104]. CAR-T cell differentiation during the phase of ex vivo propagation should be limited for optimal therapeutic outcomes [105]. One parameter impacting the performance and clinical compliance of T-cell therapy is the composition of the growth medium used for the ex vivo expansion phase. The development of a chemically defined medium has been intensely researched but, so far, FBS-based media that contain a complex combination of cell growth-promoting factors have performed better. However, as is the case with the expansion of other cells, the use of FBS is associated with risk exposure to zoonotic infections and xeno-immunization [104] and does not mimic the human microenvironments most suitable for T-cell expansion [103]. Human AB serum was tested as a growth medium supplement, but its supply is limited, and as it is not available on a large scale, batch-to-batch variability affects the consistency of its performance in ex vivo culture [103]. Recently, data published by several groups indicated that HPL (or freshly frozen plasma) can be used to successfully grow CAR-T cells.
Improving titer while maintaining quality of final formulated drug substance via optimization of CHO cell culture conditions in low-iron chemically defined media
Published in mAbs, 2018
Jianlin Xu, Matthew S. Rehmann, Xuankuo Xu, Chao Huang, Jun Tian, Nan-Xin Qian, Zheng Jian Li
In addition to titer, the consistent quality of biologics products is important to ensure patient safety and drug efficacy.6 In order to reduce raw material lot-to-lot variation, there has been a trend in the industry towards use of chemically defined media to replace serum and hydrolysate media, but some of the components in these chemically defined media may have adverse effects on protein quality attributes such as drug substance color,10-13 charge variants,14-17 and glycosylation.18-20 Since there may be more than 50 components in chemically defined media, it remains challenging to fully understand the effects and interactions of those components on cell culture performance and final protein quality.13,21,22 Although the downstream process is critical to control the quality attributes of final formulated biologic drug substances, it is quite common that quality issues originate from characteristics of the upstream process such as cell lines,21,23 media9,13,24 and bioreactor operation conditions.25,26 Since downstream processes cannot remove some of those impurities to meet the quality requirements, upstream parameters often need to be optimized, potentially sacrificing upstream titer by changing medium formulations, shifting culture temperature and even shortening culture duration.13,27,28