title: Factors influencing alginate gel biocompatibility.
abstract: Alginate remains the most popular polymer used for cell encapsulation, yet its biocompatibility is inconsistent. Two commercially available alginates were compared, one with 71% guluronate (HiG), and the other with 44% (IntG). Both alginates were purified, and their purities were verified. After 2 days in the peritoneal cavity of C57BL/6J mice, barium (Ba)-gel and calcium (Ca)-gel beads of IntG alginate were clean, while host cells were adhered to beads of HiG alginate. IntG gel beads, however, showed fragmentation in vivo while HiG gel beads stayed firm. The physicochemical properties of the sodium alginates and their gels were thoroughly characterized. The intrinsic viscosity of IntG alginate was 2.5-fold higher than that of HiG alginate, suggesting a greater molecular mass. X-ray photoelectron spectroscopy indicated that both alginates were similar in elemental composition, including low levels of counterions in all gels. The wettabilities of the alginates and gels were also identical, as measured by contact angles of water on dry films. Ba-gel beads of HiG alginate resisted swelling and degradation when immersed in water, much more than the other gel beads. These results suggest that the main factors contributing to the biocompatibility of gels of purified alginate are the mannuronate/guluronate content and/or intrinsic viscosity.
authors.affiliation: Laboratoire d'innovation et d'analyse de bioperformance, Institut de génie biomédical, École Polytechnique, Montréal, Québec H3T1J4, Canada. susan-kimberly.tam@polymtl.ca
authors.forename: Susan K
authors.initials: SK
authors.lastname: Tam
authors.forename: Julie
authors.initials: J
authors.lastname: Dusseault
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Bilodeau
authors.forename: Geneviève
authors.initials: G
authors.lastname: Langlois
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Hallé
authors.forename: L'Hocine
authors.initials: L
authors.lastname: Yahia
mesh_terms: D000464:Alginates / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D004602:Elements; D005782:Gels / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008863:Microspheres; D010529:Peritoneal Cavity / Q000166:cytology; D056951:Photoelectron Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D014783:Viscosity / Q000187:drug effects; D017155:Wettability / Q000187:drug effects
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D004602:Elements; D005782:Gels