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Media for large scale mammalian cell growth and maintenance

Technological developments resulting from the collaboration
will result in improved products from which mammalian cells
may be cultivated and will also enable production costs of
such products as vaccines and monoclonal antibodies

1. Background: Until recently, the main effort in cell culture for the purpose of expressing human and animal proteins, has centred on procaryote hosts such as E. coli. It has now been realized, however, that the human and animal proteins expressed from procaryotes are frequently in an insoluble and denatured form. They require subsequent tedious and active procedures to make them soluble and active. For these reasons, greater interest is now being displayed in mamalian cell culture, and consequently in cell nutritional and environmental requirements, both for growth and for maintenance. 2. Information Required: For many cell lines, at laboratory scale a growth medium augmented by Foetal Calf Serum (FCS) is used. This, however, is not satisfactory for large-scale culture, for reasons of supply, cost and variability. For some cell lines, e.g. for vaccine production, adult bovine serum is an attractive alternative to FCS, except that it, too, suffers from variability. There is, therefore, a need to study media characterization, even for "simpler" media containing whole-serum supplements. Where monoclonal antibody production is concerned, it is important for subsequent purifications that immunoglobins be absent from the growth media. Research sponsored by ADVANCED PROTEIN PRODUCTS LTD. has demonstrated that "immunoglobulin depleted" adult bovine serum satisfies this requirement and effectively substitutes for FCS for the particular cell lines, both myeloma and hybridoma, already tested. Each specific cell line of commercial interest, would, however, need to be tested. It is widely accepted that supplements, particularly 'growth factors',and 'spreading factors' for anchorage-dependent cell lines, would be advantageous, or even essential in specific cases. Natural materials, such as sera, are subject to variability and there is therefore widespread interest in completely 'synthetic' media. Present knowledge, however, indicates that these media are insufficient and that suitable media must apparently contain components which are themselves of natural origin, most frequently specific proteins fractionated from animal blood and other animal tissues. Not only will the media required for growth of one cell line be different from that required for another, but optimal cell maintenance during expression will almost certainly require a different medium from that required for optimal cell growth, in all of the above instances. Anchorage-dependent cell lines have traditionally been cultivated in roller bottles, a cumbersome and expensive method of scaling-up laboratory culture techniques. More recently, hollow fibre and microcarrier systems have been developed, and these show promise for significant cost reduction on a large scale. It is necessary, however, to devise simple and cost effective methods for binding cells to substrates, possibly based on the protein fibronectin. (iii) Market Description: The world market for supplying culture media for eucaryotic cells is in total modest (900-1000 million US dollars), but is growing rapidly. In the period between 1980-1985, growth was as 16% per year. Market studies indicate that the growth rate will increase to around 25% per year by 1990. This market is divided into four segments, corresponding to each stage in the production of biological molecules: - cell modification, including genetic engineering - cell culture and technology, in which cells are cultured in optimized media, for ultimate secretion of the required molecule-separation and purification, in which the isolation of the required molecule from all others present takes place - analytical control, monitoring product purity throughout the production process. Each of these stages applies precise protocols, necessitating the use of specialist high technology equipment and materials. Each stage is also interacting, making it necessary for cross-country and cross-company collaboration to take place, to successfully participate in this market. At the present time, it has been estimated that 40-45% of this market is in the US., 20-25% in JAPAN and 20-25% in Europe. Within this overall market, the categories Cell Culture and Extraction- Purification represent respectively 30-35% and 25-30%. Within the specific cell culture sector, the world market in 1984 has been estimated at 330 million dollars, divided into two parts: - 60-65% for culture of procaryotic cells, and - 35-40% for culture of eucaryotic cells. It is this latter sector which concerns the present proposal. It is estimated that because of this, 20% concerns equipment, and 80% concerns consumbles, mainly culture media. Animal cell culture is composed by simple nutrients, to which are added complex supplements, such as animal sera or their substitutes, increasingly more tightly defined. Of these, the most important in volume and in growth rate is that of sera. The growth rate of this market was 5-7% per year between 1982 and 1986, and is estimated to approach 30% per year in the near future. This will create shortages, resulting in market pressures for substitutes, as well as technological advantages: - natural sera present problems of purity and reproducibility - industrial cultures are difficult to standardize with sera. Protein concentration is the final media should be low, and this is more readily achievable with substitutes. Within the market sector 'Supplements' (i.e. sera + substitutes), 'substitutes' had a market share of around 7-8% in 1982, 10-14% in 1984, and will exceed 20% in 1987. 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Acronym: 
CELLMED
Project ID: 
123
Start date: 
12-09-1988
Project Duration: 
48months
Project costs: 
3 800 000.00€
Technological Area: 
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.