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Vectored vaccines
Published in Amine Kamen, Laura Cervera, Bioprocessing of Viral Vaccines, 2023
Zeyu Yang, Kumar Subramaniam, Amine Kamen
Cultivation of mammalian cells has been realized using various technologies including roller bottles, microcarriers, bioreactor suspension cultures, etc. Suspension cell culture remains the most effective method for the production of AdV vectors at large scale especially when compared to processes using adherent cells. Additionally, with a homogeneous concentration of nutrients, metabolites, and cellular environment, the suspension culture is easy to monitor and scale-up to control process robustness and critical quality attributes of the AdV vectors. As the main cell line for production of AdV, HEK-293 cells have been adapted to suspension culture (293S). They were further adapted to serum-free medium 293SF, enhancing the scalability, batch-to-batch reproducibility, and regulatory approval [48,49]. Suspension cultures of HEK-293 in stirred tank bioreactors are projected to scale up to 10,000L, with yields for unpurified culture in the range of 109–1010 VP/ml [44,50]. Another important cell line PER.C6 has been successfully used in GMP manufacturing processes, growing to high cell densities in serum-free suspension culture, and can be used to produce AdV vectors in a similar fashion [50].
Cell Biology for Bioprocessing
Published in Wei-Shou Hu, Cell Culture Bioprocess Engineering, 2020
In contrast to tissue cells, cancer cells proliferate in vivo. They typically carry a variety of mutations that allow them to bypass the growth control mechanism that would normally keep them in a quiescent state. Therefore, they are more readily isolated from tumor tissue for culture in vitro. Sometimes, lines of cells can also be established from normal tissues by “immortalization” through viral or oncogene transformation. Those cells that can be grown continuously without senescence typically do not have the same morphology as their normal counterparts. Their karyotype is not diploid and their growth is not contact inhibited. With adequate supplies of nutrients and growth factors, they can even overlay each other to form multiple layers of cells. Such cells include commonly used industrial cell lines like CHO cells from Chinese hamster ovary, Vero cells from green monkey kidney, and human kidney cell HEK293.
A Review of Tubeless Microfluidic Devices
Published in Eric Lagally, Krzysztof Iniewski, Microfluidics and Nanotechnology, 2017
Pedro J. Resto, David J. Beebe, Justin C. Williams
Another clever example of passive pumping for automated cell manipulation was demonstrated by Ju et al. in their work using passive pumping in cell programmable assay (CPA) chips.28 The authors created CPA chips for culturing cells and automating the process of staining using surface tension passive pumping (Figure 9.31). The system was tested using human embryonic kidney (HEK) 293 cells. The rationale for this work was that interfacing robotics and culture control systems require equipment or methods that can make regular use of the device in small biology laboratories challenging. Therefore, they developed these chips to increase the throughput of common laboratory procedures without requiring the machines and equipment needed for most high-throughput approaches—for example, the high-throughput method proposed by Puccinelli et al. using ALHs.
Advances of engineered extracellular vesicles-based therapeutics strategy
Published in Science and Technology of Advanced Materials, 2022
Hiroaki Komuro, Shakhlo Aminova, Katherine Lauro, Masako Harada
HEK293 cell-derived EVs showed minimal toxicologically and immunogenic effects in mice as well as autologous-derived EVs in terms of functionality [104,105]. Some therapeutic agents produced by HEK293 cells have been approved by the US Food and Drug Administration (FDA) or European Medicines Agency (EMA) [106]. To enhance the therapeutic efficacy of EVs from HEK293 cells, cell engineering would be a requirement to load EVs with therapeutic cargo and target them to a specific tissue type. HEK293 cells can easily be manipulated with transfected plasmids or nucleic acids with targeting molecules. In addition, the fast growth and ease of culture of these cells allow for them to be more easily mass produced. EVs derived from several cell sources all exert different biological contents, functions, and biodistribution [107]. Exploiting the unique properties of EVs derived from different cell types will be an important factor for future treatments, including their large-scale generation and drug delivery efficiency. Therefore, in-depth studies are required for the development of EV-based therapies.
Conscience and Vaccines: Lessons from Babylon 5 and COVID-19
Published in The New Bioethics, 2021
Australian Christian leaders from the Catholic, Orthodox and Anglican Churches have raised concerns regarding a deal struck between the Australian government and AstraZenaca which, in conjunction with Oxford University, developed a COVID-19 vaccine that is produced using the HEK293 cell line.19 Though this has been widely reported in the media (see e.g. Rachwani 2020), the nature of the concern seems to have been misrepresented (Bowling 2020). HEK293 is a cell line developed from a human foetal kidney (the acronym HEK refers to human embryonic kidney) most likely obtained from the remains of an elective abortion subject (van der Eb 2001).20 Use of cell lines derived from human embryonic or foetal tissues and products derived from such cell lines has been debated among Catholic scholars, with an official statement made by the Vatican in 2005 (Wong 2006, Treloar 2019, Pontifical Academy for Life 2005, Watt 2020, Austriaco 2020) and in 2008 reaffirmed in Dignitas Personae (Congregation for the Doctrine of the Faith 2008). The provision and use of vaccines developed with such cells were deemed by Catholic Church authorities to be ‘very remote mediate material cooperation’ with evil (Pontifical Academy for Life 2005). This means that the healthcare staff and patients using such vaccines would be greatly removed in time or material connection from the evil act and would not share the intention of the associated evil, i.e. the original elective abortion (Pontifical Academy for Life 2005, Fisher 2012). In essence, the Church document meant that parents could let their children be vaccinated with such a product if there was a proportionately serious risk associated with them not getting the vaccination and there was no alternative available, but that Catholics could not use these cell lines in research. Importantly, it does not force the faithful to obtain such a vaccination for their children, but only permits it, and still states that ‘everyone has the duty to make known their disagreement and to ask that their healthcare system make other types of vaccines available’ (Congregation for the Doctrine of the Faith 2008, para.35).21 Indeed one instance showing the overall commitment of Catholics towards ensuring that appropriate vaccines will be available to the whole world population is that at least one priest-scientists is working on a COVID-19 vaccine that would be more accessible in poor countries and does not involve the use of such controversial cells lines (Picón 2021). Secondly, the UK and US bishops have highlighted that taking a vaccine can be viewed as an act of charity towards one's neighbour (Moth 2020; United States Conference of Catholic Bishops 2020).