Abstract Disclosed is a process for damage-free encapsulation of a variety of core materials including viable cells. The core material is suspended in an aqueous solution of a polymeric material containing cationic groups such as an aminated glucopolysaccharide, e.g. chitosan. A temporary matrix is formed by gelling droplets of the suspension with a divalent or multivalent anion. The temporary matrix is permanently cross-linked with a polymeric material containing plural anionic groups, e.g., polyaspartic or polyglutamic acid, to form a semipermeable membrane. The interior of the microcapsule may be resolublized by subjecting the capsule to a solution of low molecular weight cations. The process produces microcapsules which are not sticky, do not clump and allow viable cell growth and proliferation.
A viable cell-containing capsule comprising a semipermeable membrane defining an enclosed intracapsular volume in which viable mammalian cells are disposed within a culture medium, said membrane consisting essentially of an inner layer comprising chitosan and an outer layer comprising a polyanionic polymer, said chitosan layer and polyanionic polymer being cross-linked by ionic interaction between cationic amine groups on said chitosan and anionic groups on said polyanionic polymer to form a water-insoluble permanent capsule, said encapsulated viable cells being capable of growth and reproduction within said capsule.
Claim 2
Dependent Claim
86 words
A viable cell-containing capsule comprising a semipermeable membrane defining an enclosed intracapsular volume in which viable mammalian cells are disposed within a culture medium, said membrane consisting essentially of an inner layer comprising chitosan and an outer layer comprising a polyanionic polymer, said chitosan layer and polyanionic polymer being cross-linked by ionic interaction between cationic amine groups on said chitosan and anionic groups on said polyanionic polymer to form a water-insoluble permanent capsule, said encapsulated viable cells being capable of growth and reproduction within said capsule.
Claim 3
Dependent Claim
13 words
The capsule of claim 1 wherein said polyanionic polymer is a polycarboxylated polymer.
Claim 4
Dependent Claim
16 words
The capsule of claim 2 wherein said polyanionic polymer is polyaspartic acid or a salt thereof.
Claim 5
Dependent Claim
16 words
The capsule of claim 2 wherein said polyanionic polymer is polyglutamic acid or a salt thereof.
Claim 6
Dependent Claim
19 words
The capsule of claim 1 wherein said chitosan layer and said polyanionic polymer are physiologically compatible with said cell.
Claim 7
Dependent Claim
13 words
The capsule of claim 1 wherein said cell comprises a genetically modified cell.