title: Biofunctionalized magnetic hydrogel nanospheres of magnetite and kappa-carrageenan.
abstract: Magnetic hydrogel kappa-carrageenan nanospheres were successfully prepared via water-in-oil (w/o) microemulsions combined with thermally induced gelation of the polysaccharide. The size of the nanospheres (an average diameter of about 50 and 75 nm) was modulated by varying the concentration of surfactant. The nanospheres contained superparamagnetic magnetite nanoparticles (average diameter 8 nm), previously prepared by co-precipitation within the biopolymer. Carboxyl groups, at a concentration of about 4 mmol g(-1), were successfully grafted at the surface of these magnetic nanospheres via carboxymethylation of the kappa-carrageenan. The carboxylated nanospheres were shown to be thermo-sensitive in the 37-45 degrees C temperature range, indicating their potential as thermally controlled delivery systems for drugs and/or magnetic particles at physiological temperatures. Finally, preliminary results have been obtained for IgG antibody conjugation of the carboxylated nanospheres and the potential of these systems for bio-applications is discussed.
authors: Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal. ana.luisa@ua.pt
authors: Ana L
authors: AL
authors: Daniel-da-Silva
authors: Sara
authors: S
authors: Fateixa
authors: António J
authors: AJ
authors: Guiomar
authors: Benilde F O
authors: BF
authors: Costa
authors: Nuno J O
authors: NJ
authors: Silva
authors: Tito
authors: T
authors: Trindade
authors: Brian J
authors: BJ
authors: Goodfellow
authors: Ana M
authors: AM
authors: Gil
mesh_terms: D000906:Antibodies / Q000378:metabolism*; D002152:Calorimetry, Differential Scanning; D002234:Carbodiimides / Q000378:metabolism; D002236:Carbohydrate Conformation; D002351:Carrageenan / Q000737:chemistry / Q000378:metabolism*; D052203:Ferrosoferric Oxide / Q000378:metabolism*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000378:metabolism*; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D008745:Methylation; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D012542:Scattering, Radiation; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature
chemical_list: D000906:Antibodies; D002234:Carbodiimides; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D002351:Carrageenan; D052203:Ferrosoferric Oxide