title: Biocompatible coating of encapsulated cells using ionotropic gelation.
abstract: The technique of immunoisolated transplantation has seen in the last twenty years improvements in biocompatibility, long term stability and methods for avoidance of fibrosis in alginate capsules. However, two major problems are not yet solved: living cellular material that is not centered in the capsule is not properly protected from the hosts' immune system and the total transplant volume needs to be reduced. To solve these problems, we present a method for applying fully biocompatible alginate multilayers to a barium-alginate core without the use of polycations. We report on the factors that influence layer formation and stability and can therefore provide data for full adjustability of the additional layer. Although known for yeast and plant cells, this technique has not previously been demonstrated with mammalian cells or ultra-high viscous alginates. Viability of murine insulinoma cells was investigated by live-dead staining and live cell imaging, for murine Langerhans' islets viability and insulin secretion have been measured. No hampering effects of the second alginate layer were found. This multi-layer technique therefore has great potential for clinical and in vitro use and is likely to be central in alginate matrix based immunoisolated cell therapy.
authors.affiliation: Biophysik und Kryotechnologie, Fraunhofer IBMT, Sankt Ingbert, Germany.
authors.forename: Friederike
authors.initials: F
authors.lastname: Ehrhart
authors.forename: Esther
authors.initials: E
authors.lastname: Mettler
authors.forename: Thomas
authors.initials: T
authors.lastname: Böse
authors.forename: Matthias Max
authors.initials: MM
authors.lastname: Weber
authors.forename: Julio Alberto
authors.initials: JA
authors.lastname: Vásquez
authors.forename: Heiko
authors.initials: H
authors.lastname: Zimmermann
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000818:Animals; D001464:Barium / Q000737:chemistry*; D045744:Cell Line, Tumor; D002470:Cell Survival; D002478:Cells, Cultured; D018914:Cells, Immobilized / Q000166:cytology; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D007515:Islets of Langerhans / Q000166:cytology*; D051379:Mice; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000464:Alginates; D020099:Coated Materials, Biocompatible; D005782:Gels; D006603:Hexuronic Acids; D001464:Barium; D020723:Glucuronic Acid
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