RESUMO
The near monodispersed ibuprofen-loaded superparamagnetic alginate (AL/IBU/Fe(3)O(4)) nanoparticles with particles size less than 200 nm were prepared via the facile heterogeneous coprecipitation of the superparamagnetic Fe(3)O(4) nanoparticles, sodium alginate (AL) and the model drug ibuprofen (IBU) from the aqueous dispersion. Then the chitosan multilayers were self-assembled onto the AL/IBU/Fe(3)O(4) nanoparticles to produce novel magnetic-targeted controlled release drug delivery system, with chitosan as the polycation (CS) and the carboxymethyl chitosan (CMCS) as the polyanion. The drug controlled releasing behaviors of the AL/IBU/Fe(3)O(4) nanoparticles and the CS multilayers encapsulated ibuprofen-loaded superparamagnetic alginate ((AL/IBU/Fe(3)O(4))@(CS-CMCS)(3)) nanoparticles were compared in the different pH media. In media with the same pH value, the encapsulated vessels exhibited the slower releasing rate.
Assuntos
Alginatos/química , Quitosana/química , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Nanotecnologia/métodos , Química Farmacêutica/métodos , Quitosana/análogos & derivados , Portadores de Fármacos , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Concentração de Íons de Hidrogênio , Ibuprofeno/química , Magnetismo , Microscopia Eletrônica de Transmissão/métodos , Tamanho da Partícula , Poliaminas/química , Polieletrólitos , Polímeros/química , Fatores de Tempo , Água/químicaRESUMO
Novel stimuli-responsive multilayer chitosan hollow microspheres with chitosan as the unique component have been fabricated by the sequential layer-by-layer electrostatic assembly technique from the sacrificial templates (polystyrene sulfonate, PSS) with chitosan (CS) as the polycation and carboxymethyl chitosan (CMCS) as the polyanion, respectively. Their hollow structure was confirmed by the TEM analysis. The DLS analysis indicated that the multilayer chitosan microcapsules were pH and ionic strength dual-responsive. Due to the biocompatibility of the single component chitosan used, the multilayer chitosan microcapsules are expected to be used in the controlled release of drugs.
Assuntos
Quitosana/química , Microesferas , Tamanho da Partícula , Poliestirenos/química , Propriedades de SuperfícieRESUMO
The disintegration-controllable stimuli-responsive polyelectrolyte multilayer microcapsules have been fabricated via the covalent layer-by-layer assembly between the amino groups of chitosan (CS) and the aldehyde groups of the oxidized sodium alginate (OSA) onto the sacrificial templates (polystyrene sulfonate, PSS) which was removed by dialysis subsequently. The covalent crosslinking bonds of the multilayer microcapsules were confirmed by FTIR analysis. The TEM analysis showed that the diameter of the multilayer microcapsules was <200nm. The diameter of the multilayer microcapsules decreased with the increasing of the pH values or the ionic strength. The pH and ionic strength dual-responsive multilayer microcapsules were stable in acidic and neutral media while they could disintegrate only at strong basic media.