title: Magnetic/pH-sensitive κ-carrageenan/sodium alginate hydrogel nanocomposite beads: preparation, swelling behavior, and drug delivery.
abstract: This work describes the preparation of magnetic and pH-sensitive beads based on κ-carrageenan and sodium alginate for use as drug-targeting carriers. Physical cross-linking using K(+)/Ca(2+) ions was applied to obtain ionic cross-linked magnetic hydrogel beads. The produced magnetite beads were thoroughly characterized by TEM, SEM/EDS, XRD, FTIR, and VSM techniques. While the water absorbency (WA) of magnetic beads was enhanced by increasing the weight ratio of κ-carrageenan, introducing magnetic nanoparticles caused a decrease in WA capacity from 15.4 to 6.3 g/g. Investigation on the swelling of the hydrogel beads in NaCl, KCl, and CaCl2 solutions revealed the disintegration of beads depending on the composition of hydrogel beads and the type of metal cations in swelling media. The swelling ratio of beads indicated pH-dependent properties with maximum water absorbing at pH 7.4. Also, it was found that the strength of pH-sensitivity of magnetic beads was low for beads with the high content of carrageenan component. The in vitro drug release studies from hydrogels exhibited significant behaviors on the subject of physiological-simulated pH values and external magnetic fields. The maximum cumulative releases obtained were 98 and 43% at pH values 7.4 and 1.2, respectively. The Introducing magnetite nanoparticles influenced the cumulative release of drug.
authors.affiliation: a Faculty of Science, Department of Chemistry , University of Maragheh , Maragheh 55181-83111 , Iran.
authors.forename: Gholam Reza
authors.initials: GR
authors.lastname: Mahdavinia
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Rahmani
authors.forename: Shiva
authors.initials: S
authors.lastname: Karami
authors.forename: Ali
authors.initials: A
authors.lastname: Pourjavadi
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002351:Carrageenan / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D012256:Riboflavin / Q000737:chemistry
chemical_list: D000464:Alginates; D004337:Drug Carriers; D006603:Hexuronic Acids; D058185:Magnetite Nanoparticles; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D020723:Glucuronic Acid; D002351:Carrageenan; D012256:Riboflavin
keywords: drug delivery; magnetic beads; pH-sensitive; sodium alginate; κ-carrageenan