title: Effect of alginate composition and gelling cation on microbead swelling.
abstract: OBJECTIVE
  The purpose of this study was to determine the roles of alginate composition and gelling cations on bead swelling, which affects its durability.
  
  
  METHODS
  Using a 2-channel droplet generator, microspheres were generated with 1.5% solutions of low viscosity high-mannuronic acid (LVM), medium viscosity high-mannuronic acid (MVM), low viscosity high-guluronic acid (LVG) and medium viscosity high-guluronic acid (MVG) alginate. They were gelled by cross-linking with 1.1% solution of either BaCl2 or CaCl2. The diameters of the microbeads were measured and recorded on day 0. The microbeads were subsequently washed and incubated in saline at 37 degrees C for 2 weeks with size assessment every 2 days. The data were normalized by calculation of the percentage change from control (day 0) for all groups of microbeads.
  
  
  RESULTS
  Diameters of all beads were between 550-700 microns on day 0. Viscosity had no effect on swelling of Ba++- and Ca++-alginate microbeads. Ca++-alginate microbeads were more prone to swelling than the corresponding Ba++-alginate beads. High G-Ba++ beads had only a modest increase in size over time, in contrast to the high M-Ba++.
  
  
  CONCLUSIONS
  Alginate composition and the gelling cation have significant effects on bead swelling.
authors.affiliation: Department of Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: Marcus D
authors.initials: MD
authors.lastname: Darrabie
authors.forename: William F
authors.initials: WF
authors.lastname: Kendall
authors.forename: Emmanuel C
authors.initials: EC
authors.lastname: Opara
mesh_terms: D000464:Alginates / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D005782:Gels / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008863:Microspheres; D010316:Particle Size; D013997:Time Factors; D014783:Viscosity
chemical_list: D000464:Alginates; D003432:Cross-Linking Reagents; D005782:Gels; D006603:Hexuronic Acids; D020723:Glucuronic Acid; C008324:mannuronic acid