Patent GB-1525022-A (GB)
Title: Cell culture method
IPC: C12M3/04
Filed: 1975-05-21
Abstract: 1525022 Culturing cells BEECHAM GROUP Ltd 6 May 1976 [21 May 1975] 21998/75 Heading A5B [Also in Division C6] A method for culturing animal cells, e.g. in the production of interferon or the preparation of virus vaccines, involves contacting the cells supported on the surface of a solid porous matrix with a film of liquid nutrient medium derived from the breakdown of a foam which is generated from a liquid nutrient medium and a gas. The cells may be treated with an interferon inducer (e.g. double-stranded RNA isolated from virus particles infecting Penicillium chrysogenum), or with an infective virus (e.g. Mareks disease virus or foot and mouth disease virus), prior to contact with the film of liquid nutrient medium. Alternatively, the matrix is submerged in the induction or infection medium, or the induction or infection medium is introduced as a thin film derived from the breakdown of a foam generated in the medium. The procedure for the recovery from the cells and medium of the interferon or virus produced, and the production of the vaccines, is conventional. The matrix may comprise spheres of diameters in the range 110mm, cylinders of lengths and diameters in the range 1-10mm, plugs of fibrous material, or netting. The spherical and cylindrical granules may be made from plastics material, ceramic, glass, an inert metal, or an inert metallic oxide; phosphate, silicate or carbide. The foam produced may be stabilized by supplementing the medium with a non-toxic surfactant (specified). It is stated that a foam generated using a nutrient medium containing at least 0.05% surfactant and in which the gas bubbles have diameters within the range 0.1 to 2mm inclusive may travel through a distance of at least 175cm without any substantial collapse of foam. The rate of flow of foam supplied to a matrix made up of spheres having diameters in the range 2-4mm or cylinders having diameters and lengths of 1-10mm is between 20 and 320cm<SP>3</SP> hr<SP>-1</SP> per cm<SP>2</SP> of bed cross-sectional area.  Referring to the figure, liquid nutrient medium from a reservoir 10 is foamed in a foam generator 1 by the introduction of gas through a sintered glass disc 7 and the foam produced passes through line 9a to the top of a cylindrical tower 2 containing a solid porous matrix 3 upon which tissue cells are supported. Liquid drained from, the matrix may be returned to the reservoir 10 through a line 18a. The apparatus also includes inlets 15, 23 for cell suspension and liquid nutrient medium, respectively, in the form of selfsealing rubber diaphragms, and a bacterial filter 17. The Examples describe: (1) the culturing. of mouse fibroblast cells on polycarbonate cylinders 4mm in diameter and 4mm long. A gas mixture containing 10% oxygen, 5% carbon dioxide and 85% nitrogen was supplied to the foam generator; (2) culturing human skin/muscle fibreblasts on 4mm silicone-treated polycarbonate beads. The cultured cells were induced to produce interferon; and (3) culturing human skin/muscle fibroblasts on 4mm polycarbonate beads that had been sprayed with PTFE aerosol spray. The results of culturing tests using human skin and muscle fibroblasts, human foreskin fibroblasts and human epithelial nasal mucosal cells on a wide variety of differing matrices are given.