Dry powder cells and cell culture reagents and methods of production thereof

Abstract

The present invention relates generally to nutritive medium, medium supplement, media subgroup and buffer formulations. Specifically, powdered nutritive medium, supplement, subgroup formulations, cell culture media comprising all of the necessary nutritive factors for in vitro cell cultivation, buffer formulations that produce particular ionic and pH conditions upon reconstitution with a solvent are provided. Particularly, methods of production of these media, supplement, subgroup, buffer formulations and kits, and methods for the cultivation of prokaryotic and eukaryotic cells using these dry powdered nutritive media, supplement, subgroup and buffer formulations are provided. Methods of producing sterile, powdered media or supplement (e.g., powdered FBS, powdered transferrin, powdered insulin, powdered organ extracts, powdered growth factors), media subgroup and buffer formulations by gamma irradiation are provided. Methods for producing dry cell powders, comprising spray-drying a cell suspension, and cells, media, media supplement, media subgroup and buffer powders produced by these methods are provided.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Application Nos. 60 / 040,314, filed Feb. 14, 1997, 60 / 058,716, filed Sep. 12, 1997, and 60 / 062,192, filed Oct. 16, 1997, the disclosures of which are entirely incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates generally to cells, nutritive media, media supplements, media subgroups and buffer formulations. Specifically, the present invention provides dry powder nutritive medium formulations, particularly cell culture medium formulations, comprising all of the necessary nutritive factors that facilitate the in vitro cultivation of cells, and methods of production of these media formulations. The invention also relates to methods of producing dry powder media supplements, such as dry powder sera (e.g., fetal bovine serum). The invention also relates to dry powder buffer formulations that produce particular ionic and pH conditions upon rehydration. The...

AI Technical Summary

Benefits of technology

This approach results in stable, easily reconstituted, and cost-effective cell culture media that can be produced in large quantities, maintaining biological activity and reducing the need for specialized equipment, while ensuring sterility and consistency between batches.

Problems solved by technology

Often, particularly in complex media compositions, stability problems result in toxic products and / or lower effective concentrations of required nutrients, thereby limiting the functional life-span of the culture media.

The rate of degradation can be influenced by pH and ionic conditions but in cell culture media, formation of these breakdown products often cannot be avoided (Tritsch et al, Exp.

Since most mammalian culture media contain riboflavin, tyrosine and tryptophan, toxic photoproducts are likely produced in most cell culture media.

However, only a limited number of commercial culture media are available, except for those custom formulations supplied by the manufacturer.

Although dry powder media formulations may increase the shelf-life of some media, there are a number of problems associated with dry powdered media, especially in large scale application.

Due to the corrosive nature of dry powder media, mixing tanks must be periodically replaced.

Liquid media have the disadvantages, however, that they often do require the addition of supplements (e.g., L-glutamine, serum, extracts, cytokines, lipids, etc.) for optimal performance in cell cultivation.

Furthermore, liquid medium is often difficult to sterilize economically, since many of the components are heat labile (thus obviating the use of autoclaving, for example) and bulk liquids are not particularly amenable to penetrating sterilization methods such as gamma or ultraviolet irradiation; thus, liquid culture media are most often sterilized by filtration, which can become a time-consuming and expensive process.

Furthermore, production and storage of large batch sizes (e.g., 1000 liters or more) of liquid culture media are impractical, and the components of liquid culture media often have relatively short shelf lives.

Despite these advantages, however, concentrated liquid media still have the disadvantages of their need for the addition of supplements (e.g., FBS, L-glutamine or organ / gland extracts), and may be difficult to sterilize economically.

However, powdered media have several distinct disadvantages.

For example, some of the components of powdered media become insoluble or aggregate upon lyophilization such that resolubilization is difficult or impossible.

Furthermore, powdered media typically comprise fine dust particles which can make them particularly difficult to reconstitute without some loss of material, and which may further make them impractical for use in many biotechnology production facilities operating under GMP / GLP, USP or ISO 9000 settings.

Additionally, many of the supplements used in culture media, e.g., L-glutamine and FBS, cannot be added to the culture medium prior to lyophilization or ball-milling due to their instability or propensity to aggregate upon concentration or due to their sensitivity to shearing by processes such as ball-milling.

Finally, many of these supplements, particularly serum supplements such as FBS, show a substantial loss of activity or are rendered completely inactive if attempts are made to produce powdered supplements by processes such as lyophilization.

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