title: Self-cross-linking polyelectrolyte complexes for therapeutic cell encapsulation.
abstract: Self-cross-linking polyelectrolytes are used to strengthen the surface of calcium alginate beads for cell encapsulation. Poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride), containing 30 mol % 2-aminoethyl methacrylate, and poly(sodium methacrylate), containing 30 mol % 2-(methacryloyloxy)ethyl acetoacetate, were prepared by radical polymerization. Sequential deposition of these polyelectrolytes on calcium alginate films or beads led to a shell consisting of a covalently cross-linked polyelectrolyte complex that resisted osmotic pressure changes as well as challenges with citrate and high ionic strength. Confocal laser fluorescence microscopy revealed that both polyelectrolytes were concentrated in the outer 7-25 microm of the calcium alginate beads. The thickness of this cross-linked shell increased with exposure time. GPC studies of solutions permeating through analogous flat model membranes showed molecular weight cut-offs between 150 and 200 kg/mol for poly(ethylene glycol), suitable for cell encapsulation. C 2C 12 mouse cells were shown to be viable within calcium alginate capsules coated with the new polyelectrolytes, even though some of the capsules showed fibroid overcoats when implanted in mice due to an immune response.
authors.affiliation: Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada.
authors.forename: M A Jafar
authors.initials: MA
authors.lastname: Mazumder
authors.forename: Feng
authors.initials: F
authors.lastname: Shen
authors.forename: Nicholas A D
authors.initials: NA
authors.lastname: Burke
authors.forename: Murray A
authors.initials: MA
authors.lastname: Potter
authors.forename: Harald D H
authors.initials: HD
authors.lastname: Stöver
mesh_terms: D000090:Acetoacetates; D000464:Alginates / Q000737:chemistry*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D019343:Citric Acid / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D016503:Drug Delivery Systems; D015195:Drug Design; D004573:Electrolytes / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008567:Membranes, Artificial; D008689:Methacrylates / Q000737:chemistry*; D051379:Mice; D015394:Molecular Structure; D008970:Molecular Weight; D009994:Osmolar Concentration; D009997:Osmotic Pressure; D010539:Permeability / Q000187:drug effects; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry*; D013499:Surface Properties
chemical_list: C534569:2-(methacryloyloxy)ethyl acetocetate; D000090:Acetoacetates; D000464:Alginates; D003432:Cross-Linking Reagents; D004573:Electrolytes; D006603:Hexuronic Acids; D008567:Membranes, Artificial; D008689:Methacrylates; D011109:Polymethacrylic Acids; C401965:poly(2-(trimethylamino)ethyl methacrylate); C030613:polymethacrylic acid; D019343:Citric Acid; D011092:Polyethylene Glycols; C072703:2-aminoethylmethacrylate; D020723:Glucuronic Acid