title: Fabrication of patterned calcium cross-linked alginate hydrogel films and coatings through reductive cation exchange.
abstract: Calcium cross-linked alginate hydrogels are widely used in targeted drug delivery, tissue engineering, wound treatment, and other biomedical applications. We developed a method for preparing homogeneous alginate hydrogels cross-linked with Ca(2+) cations using reductive cation exchange in homogeneous iron(III) cross-linked alginate hydrogels. Treatment of iron(III) cross-linked alginate hydrogels with calcium salts and sodium ascorbate results in reduction of iron(III) cations to iron(II) that are instantaneously replaced with Ca(2+) cations, producing homogeneous ionically cross-linking hydrogels. Alternatively, the cation exchange can be performed by photochemical reduction in the presence of calcium chloride using a sacrificial photoreductant. This approach allows fabrication of patterned calcium alginate hydrogels through photochemical patterning of iron(III) cross-linked alginate hydrogel followed by the photochemical reductive exchange of iron cations to calcium.
authors.affiliation: Department of Chemistry and Biomolecular Science, Clarkson University, 8 Clarkson Ave., Potsdam, NY 13699-5810, USA. Electronic address: bruchem@clarkson.edu.
authors.forename: Marion
authors.initials: M
authors.lastname: Bruchet
authors.affiliation: Department of Chemistry and Biomolecular Science, Clarkson University, 8 Clarkson Ave., Potsdam, NY 13699-5810, USA. Electronic address: amelman@clarkson.edu.
authors.forename: Artem
authors.initials: A
authors.lastname: Melman
mesh_terms: D000464:Alginates / Q000737:chemistry; D002118:Calcium / Q000737:chemistry*; D002412:Cations; D002942:Circular Dichroism; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004563:Electrochemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D007474:Ion Exchange; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D008027:Light; D008756:Methylgalactosides / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D000464:Alginates; D002412:Cations; D020099:Coated Materials, Biocompatible; D003432:Cross-Linking Reagents; D006603:Hexuronic Acids; D008756:Methylgalactosides; C109801:hydrogel film; D020723:Glucuronic Acid; D007501:Iron; D002118:Calcium
keywords: Alginate; Hydrogel; Ionic cross-linking; Iron; Photochemistry