Preparation of substances with encapsulated cells
First Claim
1. A process for producing a substance which is produced by living cells, said process comprising the steps of:
- A. encapsulating said cells within semipermeable membranes having a selected upper limit of permeability, said encapsulating being effected by forming said semipermeable membranes by reacting cationic groups on polymer chains having a molecular weight greater than about 3000 with anionic groups on a polysaccharide gel encapsulating said cells to crosslink surface layers of said polysaccharide gel to form said semipermeable membranes;
B. suspending said encapsulated cells in an aqueous culture medium;
C. allowing said cells to undergo metabolism in vitro and to produce said substance; and
D. harvesting said substance either from said aqueous medium or from within said membranes.
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Accused Products
Abstract
Disclosed is a system and process for producing substances produced in cells such as antibodies and biological response modifiers. Cells which produce the substance of interest are encapsulated within semipermeable membranes having an upper limit of permeability sufficient to allow traverse of ions, amino acids and other cell nutrients and then suspended in a culture medium. Serum components or other high molecular weight materials needed for ongoing viability and normal in vitro metabolism of certain types of cells may be included within the intracapsular volume and may be excluded from the extracapsular medium by limiting the permeability of the membranes. The substance of interest collects either in the intracapsular volume or the extracapsular medium, depending on the degree of permeability of the membranes and on the molecular weight of the substance.
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Citations
25 Claims
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1. A process for producing a substance which is produced by living cells, said process comprising the steps of:
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A. encapsulating said cells within semipermeable membranes having a selected upper limit of permeability, said encapsulating being effected by forming said semipermeable membranes by reacting cationic groups on polymer chains having a molecular weight greater than about 3000 with anionic groups on a polysaccharide gel encapsulating said cells to crosslink surface layers of said polysaccharide gel to form said semipermeable membranes; B. suspending said encapsulated cells in an aqueous culture medium; C. allowing said cells to undergo metabolism in vitro and to produce said substance; and D. harvesting said substance either from said aqueous medium or from within said membranes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A system for producing a substance which is produced by living cells comprising viable cells encapsulated within semipermeable membranes and suspended in an aqueous culture medium for said cells,
the semipermeable membranes of said encapsulated viable cells having an upper limit of permeability sufficient to allow traverse of nutrients required by said cells, said semipermeable membranes comprising a polysaccharide gel having plural anionic groups cross-linked with a polymer having a molecular weight greater than about 3000 and having plural cationic groups, said semipermeable membranes encapsulating suspended viable, healthy, physiologically active cells disposed in a medium which includes all components (A) needed to maintain viability of said cells and which components are of a size in excess of the upper permeability limit of said membranes, said aqueous culture medium comprising all components (B) needed to maintain viability of said cells having a molecular weight below the upper permeability limit of said membranes.
Specification